FR3142915A1 - New bimetallic heterogeneous catalyst based on copper, its preparation process and its use - Google Patents

Abstract

The present invention relates to the use of a supported bimetallic catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( H2) to obtain ethylene glycol, the catalyst. (Not shown)

Description

New heterogeneous bimetallic copper-based catalyst, its preparation process and use

The present invention relates to a novel bimetallic heterogeneous catalyst, its preparation process and its use, in particular for the synthesis of ethylene glycol from the hydrogenation of oxamide or oxamate.

Ethylene glycol is an important material in the chemical industry, allowing various applications such as antifreeze or refrigerant, but especially in the production of textile fibers and polyester resins. Ethylene glycol can be used as a monomer in the manufacture of polyester, and in particular PET (Polyethylene terephthalate) in the presence of terephthalic acid. PET is a polymer widely used in the textile industry, which today is mainly produced from petroleum-based products that generate a large quantity of greenhouse gases, including carbon dioxide.

A classic method of manufacturing ethylene glycol is made from naphtha and is shown schematically below:

The recovery of carbon dioxide _CO2 is a major challenge for reducing greenhouse gas emissions. Another little-studied route for the synthesis of ethylene glycol is the hydrogenation of oxamides or oxamates.

Oxamide compounds can be synthesized directly by a double oxidative carbonylation of an amine, in the presence of a catalyst, notably palladium (Pd).

Oxamate compounds can be synthesized directly by oxidative carbonylation of an alcohol and an amine, in the presence of a catalyst, notably palladium (Pd).

Thus the consumption of _CO2 can be achieved during the synthesis of oxamides or oxamates, which are precursors for producing ethylene glycol via a hydrogenation reaction catalyzed with transition metals, as homogeneous or heterogeneous catalysts, as shown schematically below:

A homogeneous transition metal catalyst is a catalyst that is soluble in the reaction solvent and forms a single phase.

A heterogeneous transition metal catalyst is a catalyst that is not soluble involving a reaction involving two phases, for example liquid-solid.

The hydrogenation reaction of oxamide or oxamate to ethylene glycol is catalyzed by metals. The hydrogenation step of oxamides described in Dong et al (Nature Communication, 7:12075, DOI: 10.1038/ncomms12075, 2016) is carried out in homogeneous catalysis with organometallic complexes of ruthenium or iron.

For many years, there has been a need for a low-cost and environmentally friendly route to prepare ethylene glycol.

To date, a heterogeneous catalyst, easy to prepare, allowing an efficient synthesis is being sought. environmentally friendly ethylene glycol from oxamide or oxamate, easily industrializable and safe.

Ethylene glycol also represents a model compound for the cleavage by the action of hydrogen, namely hydrogenolysis, of the carbon-carbon (C-C) and/or carbon-oxygen (C-O) bonds of the diol groups -CHOH-CHOH- present in the carbohydrate molecules (polyols) contained in the biomass. Thus, a catalyst allowing by hydrogenolysis the cleavage of the C-C and C-O bonds of ethylene glycol would allow a depolymerization of the biomass by cleavage of the C-C and/or C-O bonds of the diol groups present in the biomass.

One of the aims of the invention is to propose a process for preparing ethylene glycol, from oxamide or oxamate by a reaction using a heterogeneous bimetallic catalyst, in particular based on copper associated with another metal.

Another object of the invention is a process for preparing ethylene glycol having efficient yields and significant selectivity.

Another aim of the invention is the preparation of ethylene glycol without using toxic reagents.

Another aim of the invention is the preparation of ethylene glycol, using recyclable or recycled reagents and an efficient and reusable heterogeneous catalyst.

Another aim of the invention is to propose a process for the hydrogenolysis of ethylene glycol using a heterogeneous bimetallic catalyst.

Another aim of the invention is to propose a process for depolymerizing biomass using a heterogeneous bimetallic catalyst.

Another aim of the invention is to propose a new heterogeneous bimetallic catalyst on a support.

Another aim of the invention is to provide a heterogeneous catalyst usable in a continuous flow process.

Another aim of the present invention is to propose a simple, industrializable and optimized preparation process for this catalyst.

Use

A first object of the present invention is the use of a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

The inventors observed unexpectedly and surprisingly that a bimetallic catalyst of copper and a metal M chosen from Mn, Co, Ni and Iron, on a support makes it possible to catalyze the hydrogenation of oxamides or oxamates into ethylene glycol, in particular with a yield of up to 80% in ethylene glycol.

For the purposes of the present invention, the term “oxamide” means the oxamide derivative 1,1'-oxalyl diamine corresponding to the amine NR _a R _b , of formula:

For the purposes of the present invention, the term “oxamate” means the oxalate derivative comprising an amine group (NR _a R _b ) and an alkoxide or alcohol group, of the following formula:

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamide compound by a hydrogenation reaction of said oxamide compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamate compound by a hydrogenation reaction of said oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from a mixture of oxamide and oxamate by a hydrogenation reaction of said mixture of oxamide and oxamate with hydrogen (H ₂ ) to obtain ethylene glycol.

It is understood that the Cu-M/Support catalyst is a heterogeneous catalyst, the catalyst being in solid phase and the reactants being in liquid or gaseous form.

The use of a heterogeneous catalyst has the advantage of facilitating the separation of the catalyst from the other species involved in the reaction, allowing easy recovery and reuse of the catalyst and limiting contamination of the product with transition metals.

The use of a heterogeneous catalyst also has the advantage of allowing the catalyst to be fixed in the reactor in an enclosure such as a cartridge when operating under continuous flow and thus obtaining products at the reactor outlet free of catalyst.

For the purposes of the present invention, the term “catalyst” or “supported catalyst” means ", a material consisting of a support on which catalytic sites are located. It is understood that the bimetallic catalyst comprises a support and atoms of the elements copper and the metal M. The total weight of the catalyst corresponds to the weight of the support and that of the two metals, namely copper and the metal M.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol, in which said support is an oxide, in particular zirconium dioxide (ZrO ₂ ) or alumina (γ-Al ₂ O ₃ ).

Advantageously, the support is an oxide such as zirconium dioxide ZrO ₂ and alumina (γ-Al ₂ O ₃ ).

For the purposes of the present invention, the term “oxide” means a transition metal oxide in solid form and insoluble in solvents.

Use with Cu-Mn catalyst / Support

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and manganese on a support, of formula Cu-Mn / support, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and manganese on an oxide support, of formula Cu-Mn / Oxide, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and manganese on a zirconium dioxide support, of formula Cu-Mn / ZrO ₂ , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and manganese on a γ-alumina support, of formula Cu-Mn/γ- _Al2O3 , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen _{( H2} ) to obtain ethylene glycol.

Use with Cu-Co catalyst / Support

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and cobalt on a support, of formula Cu-Co / support, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and cobalt on an oxide support, of formula Cu-Co/oxide, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( _H2 ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and cobalt on a zirconium dioxide support, of formula Cu-Co / ZrO ₂ , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and cobalt on a γ-alumina support, of formula Cu-Co/γ– _Al2O3 , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen _{( H2} ) to obtain ethylene glycol.

Use with Cu-Ni catalyst / Support

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and nickel on a support, of formula Cu-Ni / support, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and nickel on an oxide support, of formula Cu-Ni/oxide, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( _H2 ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and nickel on a zirconium dioxide support, of formula Cu-Ni / ZrO ₂ , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and nickel on a γ-alumina support, of formula Cu-Ni/γ– _Al2O3 , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen _{( H2} ) to obtain ethylene glycol.

Use with Cu-Fe catalyst / Support

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and iron on a support, of formula Cu-Fe/support, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( _H2 ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and iron on an oxide support, of formula Cu-Fe/oxide, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( _H2 ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and iron on a zirconium dioxide support, of formula Cu-Fe/ _ZrO2 , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen ( _H2 ) to obtain ethylene glycol.

According to a particular embodiment, the invention relates to the use as defined above of a bimetallic supported catalyst comprising copper and iron on a γ-alumina support, of formula Cu-Fe / γ- Al ₂ O ₃ , in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol.

Oxamide

According to a particular embodiment, the invention relates to the use as defined above, in which said oxamide is of the following formula 1:

• un atome d’hydrogène,

• un groupement alkyle en C₁à C₂₀, linéaire ou ramifié,
• un groupement alcényle en C₂à C₂₀, linéaire ou ramifié,
• un groupement hétéroalkyle en C₁à C₂₀, linéaire ou ramifié,,
  • un groupement aryle ou hétéroaryle en C₃à C₂₀
  • un groupement alkyl-aryle ou alkyl-hérétoaryle en C₅à C₂₀,
  • un groupement cycloalkyle en C₃à C₁₀,

in which R _a and R _b represent independently of each other:

• a hydrogen atom,

• a linear or branched _C1 to _C20 alkyl group,
• a linear or branched _C2 to _C20 alkenyl group,
• a linear or branched _C1 to _C20 heteroalkyl group,
  • a _C3 to _C20 aryl or heteroaryl group
  • a _C5 to _C20 alkyl-aryl or alkyl-heretoaryl group,
  • a _C3 to _C10 cycloalkyl group,

at least one of the groups R _a or R _b being other than hydrogen,

R _a and R _b can be covalently bonded and form a cycle.

According to a particular embodiment, the invention relates to the use as defined above, in which said oxamide is chosen from oxamides prepared with diethylamine, piperidine, pyrrolidine, morpholine and aniline, preferably piperidine.

Oxamate

According to a particular embodiment, the invention relates to the use as defined above, in which said oxamate is of the following formula 2:

• un atome d’hydrogène,

• un groupement alkyle en C₁à C₂₀, linéaire ou ramifié,
• un groupement alcényle en C₂à C₂₀, linéaire ou ramifié
• un groupement hétéroalkyle en C₁à C₂₀, linéaire ou ramifié,
  • un groupement aryle ou hétéroaryle en C₃à C₂₀
  • un groupement alkyl-aryle ou alkyl-hérétoaryle en C₅à C₂₀,
  • un groupement cycloalkyle en C₃à C₁₀,

in which R _a and R _b represent independently of each other:

• a hydrogen atom,

• a linear or branched _C1 to _C20 alkyl group,
• a linear or branched _C2 to _C20 alkenyl group
• a linear or branched _C1 to _C20 heteroalkyl group,
  • a _C3 to _C20 aryl or heteroaryl group
  • a _C5 to _C20 alkyl-aryl or alkyl-heretoaryl group,
  • a _C3 to _C10 cycloalkyl group,

at least one of the groups R _a or R _b being other than hydrogen,

R _a and R _b can be covalently linked and form a cycle,

• alkyle en C₁à C₁₀, linéaire ou ramifié, et
• cycloalkyle en C₃à C_10,
• un groupement aryle ou héréroaryle en C₃à C_20,

• un groupement alkyl-aryle ou alkyl-hétéroaryle en C₅à C₂₀.

in which R _c represents a group chosen from:

• _C1 - _C10 alkyl, linear or branched, and
• C ₃ to C _{10 cycloalkyl,}
• a _C3 to C20 aryl or heteroaryl group _,

• a _C5 to _C20 alkyl-aryl or alkyl-heteroaryl group.

According to a particular embodiment, the invention relates to the use as defined above, in which said oxamate is chosen from oxamates prepared with diethylamine, piperidine, pyrrolidine, morpholine and aniline, preferably piperidine and with water, methanol, ethanol or isopropanol.

From CO2

Advantageously, the oxamides used can be obtained by a carbonylation reaction of an amine in the presence of CO and oxygen.

Advantageously, the oxamates used can be obtained by a carbonylation reaction of an amine and an alcohol or water in the presence of CO and oxygen.

Advantageously, carbon monoxide CO for the preparation of oxamide or oxamate comes from the electrolysis of carbon dioxide _CO2 into carbon monoxide CO.

Thus, advantageously, the synthesis of ethylene glycol is carried out from the recovery of _CO2 .

Use with catalyst preparation by soft chemistry

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is prepared by mixing the support in powder form and an aqueous solution of copper salts and the metal M, M being chosen from Mn, Co, Ni and Fe, followed by drying and calcination.

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is prepared by mixing the support in powder form and an aqueous solution of copper salts and the metal M, M being chosen from Mn, Co, Ni and Fe, free of additive or surfactant, in particular free of an ammonia solution, followed by drying of the material obtained and calcination thereof.

It is understood that the mixture of the support in powder form and an aqueous solution of copper salts and of the metal M, M being chosen from Mn, Co, Ni and Fe, consists of bringing a solution of copper salts and of the metal M into contact with a support and therefore of impregnation of the support by the copper salts and of the metal M, namely the deposition of the copper atoms and of the metal M on the surface of the support.

“Drying” means an operation consisting of heating the material in ambient air in a closed enclosure at a temperature of the order of 60 to 100°C for 10 to 24 hours in order to dry the material, namely to eliminate water molecules, namely free water, adsorbed on the surface or interstitial.

"Calcination" means an operation consisting of heating the solid material in ambient air in a closed enclosure to a high temperature of the order of 400 to 1,000°C in order to activate it or to modify the physical characteristics of the support and to eliminate the water of constitution and the salts of the metal precursors such as nitrates and acetates. After calcination, said material is free of water.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel du métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dans un volume d’eau de 5 à 10 mL, sur un support sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

Advantageously, the catalyst used is prepared as follows with a preparation process comprising the following steps:

• a step A of impregnation of a copper salt and a salt of the metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, in a volume of water of 5 to 10 mL, on a support in powder form, with a mass of the solution / mass of support ratio of from 0.6 to 1.0;

• une étape B de séchage dudit mélange homogène, pour obtenir le catalyseur Cu-M / Support sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination dudit mélange homogène sec pour obtenir ledit catalyseur.

to obtain the Cu-M catalyst / Support in the form of a homogeneous mixture,

• a step B of drying said homogeneous mixture, to obtain the Cu-M/Support catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination of said dry homogeneous mixture to obtain said catalyst.

For the purposes of the present invention, the term “homogeneous mixture” means the homogeneous material obtained by mixing an aqueous solution of metal salts with the support in the form of a solid powder, said aqueous solution of metal salts being distributed homogeneously on the surface of the particles constituting the support and in the interstices of said particles.

By "dry homogeneous mixture" is meant a homogeneous mixture in which the majority of free water molecules, adsorbed on the surface or in the interstices of the support particles are eliminated, for example by drying at 60 to 100°C, in particular 80°C to obtain a powder. The preparation of the catalyst leads to the formation of the corresponding insoluble metal oxides because the metal salts of the metals such as nitrate, are completely eliminated after the calcination step at 600°C.

Advantageously, in impregnation step A, said aqueous solution containing the salts of copper and of the metal M, M being chosen from Mn, Co, Ni and Fe, is free of additive and surfactant. In other words, said aqueous impregnation solution consists of a demineralized solution of water in which the salts of copper and of the metal M are dissolved.

Advantageously the salt of the metal M is nitrate and the copper salt is copper nitrate.

The use according to the invention is therefore implemented with a catalyst prepared with an aqueous solution, a green solvent without danger in comparison with the organic solvents, implemented in the prior art. Advantageously, additional additives and surfactants in the synthesis of the catalyst are not necessary, which makes it more industrializable at a lower cost.

“Green solvent” means a non-toxic, biodegradable or agro-sourced substitute solvent that has the same properties as the toxic solvents it replaces.

Use with a catalyst having a characteristic relating to the specific surface area.

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g.

The range from 1 to 250 m²/g includes the following ranges; from 1 to 25 m²/g; from 25 to 50 m²/g; from 50 to 75 m²/g; from 75 to 100 m²/g; from 100 to 125 m²/g; from 125 to 150 m²/g; from 150 to 175 m²/g; from 175 to 200 m²/g; from 200 to 225 m²/g; from 225 to 250 m²/g.

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst has a surface area, analyzed by BET, of 1 to 50 m²/g.

The range from 1 to 50 m²/g includes the following ranges: from 1 to 10 m²/g; from 10 to 20 m²/g; from 20 to 30 m²/g; from 30 to 40 m²/g; from 40 to 50 m²/g.

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst has a surface area, analyzed by BET, of 1 to 10 m²/g, preferably approximately 5 m²/g.

The range of 1 to 10 m²/g includes the following ranges: 1 to 2 m²/g; 2 to 3 m²/g; 3 to 4 m²/g; 4 to 5 m²/g; 5 to 6 m²/g; 6 to 7 m²/g; 7 to 8 m²/g; 8 to 9 m²/g, 9 to 10 m²/g, in particular about 5 m²/g.

Use with a ZrO supported catalyst ₂ having a specific crystal structure

According to a particular embodiment, the invention relates to the use as defined above, of a Cu-M / ZrO ₂ catalyst in which said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system.

A "monoclinic crystal system" means a system having one of the following point groups as its point symmetry group: 2, m or 2/m.

According to a particular embodiment, the invention relates to the use as defined above of a Cu-M / ZrO ₂ catalyst in which said crystalline phase represents from 50 to 90% by total weight of the catalyst.

According to a particular embodiment, the invention relates to the use as defined above of a Cu-M / ZrO ₂ catalyst in which said crystalline phase is baddeleyite.

According to a particular embodiment, the invention relates to the use as defined above of a Cu-M / ZrO ₂ catalyst in which the catalyst support is natural zirconium dioxide (ZrO ₂ ) crystallizing in monoclinic baddeleyite.

For the purposes of the present invention, the term "baddeleyite" means a natural zirconium oxide of formula ZrO ₂ , containing from 0.1% to 5% of hafnium oxide, and crystallizing in a monoclinic crystal system. The characteristics of baddeleyite such as the composition and the crystallographic structure, in particular the space group with the dimensions of the crystal lattice, are reported and accessible in the prior art and known to those skilled in the art, such as in Kudoh, Y. et al., (Phys Chem Minerals 13, 233–237 (1986)) or McCullough J D. et al. (Acta Crystallographica 12 (1959) 507-511).

According to a particular embodiment, the invention relates to the use as defined above, in which the support of the zirconium dioxide ZrO ₂ catalyst comprises impurities such as Hafnium (Hf), Rhenium (Re) and Silicon (Si) atoms.

Advantageously, the mass percentage ratio between Hafnium atoms and zirconium atoms (Hf/Zr) is less than 5%.

Advantageously, the mass percentage ratio between Rhenium atoms and zirconium atoms (Re/Zr) is less than 5%.

Advantageously, the mass percentage ratio between the silicon atoms and the zirconium atoms (Si/Zr) is less than 2%.

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst has a microstructure whose crystallite size is from 15 to 100 nm, preferably from 15 to 50 nm.

The crystalline structure of the catalyst can be analyzed by X-ray powder diffraction. The analysis of the phases present and that of their structure are carried out by the attribution of the diffraction peaks present in the diffraction diagram obtained in comparison with reference files.

The crystalline phase of baddeleyite zirconium dioxide ZrO ₂ is for example indicated in the ICDD reference file n° 00-037-1484.

From the diffraction pattern, the crystallite size can be evaluated according to the following Scherrer formula:

The “15 to 100 nanometer” range includes the following ranges: 15 to 20 nm; 20 to 30 nm; 30 to 40 nm; 40 to 50 nm; 50 to 60 nm; 60 to 70 nm; 70 to 80 nm; 80 to 90 nm; 90 to 100 nm.

Use with a catalyst having particular Cu and M metal contents

According to a particular embodiment, the invention relates to the use as defined above, in which the total content of the bimetallic elements of copper and of the metal M, M being chosen from Mn, Co, Ni and Fe, is from 0.5 to 25% by total weight of the catalyst.

The total weight of the catalyst includes the mass of the support and the mass of the bimetallic elements copper and metal M.

The 0.5 to 25% range includes the following ranges: 0.5 to 5%; 5 to 10%; 10 to 15%; 15 to 20%; 20 to 25%

According to a particular embodiment, the invention relates to the use as defined above, in which the total content of the bimetallic elements copper and the metal M is from 5 to 20% by total weight of the catalyst.

By "total content of bimetallic elements of copper and metal M" is meant a content corresponding to the addition of the elements copper and metal M in the catalyst.

According to a particular embodiment, the invention relates to the use as defined above, in which the total content of the copper element is from 1 to 25% by total weight of the catalyst, in particular from 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to the use as defined above, in which the total content of the metal element M, M being chosen from Mn, Co, Ni and Fe, is from 1 to 25% by total weight of the catalyst, in particular from 1 to 10% by total weight of the catalyst.

• la teneur totale de l’élément cuivre est de 1 à 25% en poids total du catalyseur, en particulier de 1 à 10% en poids total du catalyseur,
• et la teneur totale de l’élément métal M est de 1 à 25% en poids total du catalyseur, en particulier de 1 à 10% en poids total du catalyseur.

According to a particular embodiment, the invention relates to the use as defined above, in which:

• the total content of the copper element is 1 to 25% by total weight of the catalyst, in particular 1 to 10% by total weight of the catalyst,
• and the total content of the metal element M is 1 to 25% by total weight of the catalyst, in particular 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to the use as defined above, in which the mass quantity of copper is greater than that of the metal M.

According to a particular embodiment, the invention relates to the use as defined above, in which the mass quantity of the metal M is greater than that of copper.

According to a particular embodiment, the invention relates to the use as defined above, in which the weight ratio between the metal M and the copper varies from 1:1 to 1:10, preferably from 1:1 to 1:5, in particular the ratio is 1:2.

According to a particular embodiment, the invention relates to the use as defined above, in which the mass composition of the metal M, M being chosen from Mn, Co, Ni and Fe and copper of the catalyst is M(5%)Cu(10%).

The mass composition M(5%)Cu(10%) corresponds to a content of 5% of metal M in total weight of the catalyst and 10% of Cu in total weight of the catalyst, i.e. a mass ratio between metal M and copper of 1:2.

Use with CuMn catalyst / Support having surface characteristic on Cu and Co

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is CuMn/Support and said catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) and/or in which the element manganese is present at oxidation states (II), (III) and (IV).

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is CuMn/ZrO ₂ and said catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) and/or element manganese at an oxidation state (II).

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is CuMn/γ-Al ₂ O ₃ and said catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) and/or element manganese at an oxidation state (III).

Use with CuCo/ZrO catalyst ₂ exhibiting a surface characteristic on Cu and Co

According to a particular embodiment, the invention relates to the use as defined above, in which said catalyst is CuCo/ZrO ₂ and has an amount of more than 50 mol% of element copper at an oxidation state (II) and/or element cobalt at an oxidation state (II).

The inventors unexpectedly found that for the hydrogenation reaction of oxamides or oxamates in ethylene glycol, the bimetallic CoCu/ _ZrO2 catalysts could be directly used after preparation by calcination in air without a prior step of reduction in hydrogen of the copper and cobalt atoms before use of the catalyst in the hydrogenation reaction.

Advantageously, the use of a catalyst in which a majority of the copper and cobalt elements are already present in the oxidized state makes it possible to use said catalyst without prior reduction of the copper and cobalt elements of the catalyst before implementing the hydrogenation reaction of the oxamides or oxamate to ethylene glycol. This also makes it possible to avoid storing the catalysts in an inert atmosphere to avoid oxidation of the copper and cobalt atoms.

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) and more than 50% of element cobalt at an oxidation state (II).

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has an amount of more than 70 mol% of element copper at an oxidation state (II) and more than 65% of element cobalt at an oxidation state (II).

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) in the form of CuO and more than 50% of element cobalt at an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has an amount greater than 70 mol% of element copper at an oxidation state (II) in the form of CuO and an amount greater than 65 mol% of element cobalt at an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has:

- a quantity of 10 to 30 mol% of copper element in the metallic state at an oxidation state (0) or at an oxidation state (I) in the form of Cu ₂ O

-and a quantity of 10 to 35 mol% of cobalt element in the metallic state at an oxidation state (0).

• une quantité supérieure à 70% molaire d’élément cuivre à un degré d’oxydation (II) sous forme de CuO,
• une quantité de 10 à 30% molaire d’élément cuivre à l’état métallique à un degré d’oxydation (0) ou à un degré d’oxydation (I) sous forme de Cu₂O
• une quantité de 10 à 35% molaire d’élément cobalt à l’état métallique à un degré d’oxydation (0),
• et une quantité supérieure à 65% molaire d’élément cobalt à un degré d’oxydation (II) sous forme de Co₂O₃ou Co(OH)₂.

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst has:

• an amount greater than 70 mol% of the element copper in oxidation state (II) in the form of CuO,
• an amount of 10 to 30 mol% of the element copper in the metallic state at an oxidation state (0) or at an oxidation state (I) in the form of Cu ₂ O
• an amount of 10 to 35 mol% of the element cobalt in the metallic state at an oxidation state (0),
• and an amount greater than 65 mol% of the element cobalt in an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

Use with a CuCo/ZrO2 catalyst _of particular morphology

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst is in the form of a population of micrometric particles from 1 to 500 µm.

The 1 to 500 µm range includes the following ranges: 1 to 50 µm; 50 to 100 µm; 100 to 200 µm; 200 to 300 µm, 300 to 400 µm.

By "particles" we mean distinct clusters having either visual or mechanical coherence.

According to a particular embodiment, the invention relates to the use as defined above, in which said CuCo / ZrO ₂ catalyst is in the form of a population of particles of rounded morphology.

For the purposes of the present invention, the term “rounded particles” means particles having no edge, corner or beveled edge.

Catalyst

A second subject of the invention relates to a bimetallic supported catalyst, comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe.

Cu-M / γ-Al catalyst ₂ O ₃

According to a particular embodiment, the invention relates to a bimetallic supported catalyst comprising copper and metal M, M being chosen from Mn, Co, Ni and Fe, on a γ-alumina support, of formula Cu-M/ γ-Al ₂ O ₃ ,

wherein said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, preferably of 100 to 200 m²/g, preferentially of 150 to 160 m²/g

and optionally in which said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, comprising a crystallite size of less than 10 nm.

Cu-M/ZrO catalyst ₂

According to a particular embodiment, the invention relates to a bimetallic supported catalyst comprising copper and metal M, M being chosen from Mn, Co, Ni and Fe, on a zirconium dioxide support, of formula Cu-M/ZrO ₂ ,

wherein said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, preferably of 1 to 50 m²/g, preferentially of 1 to 10 m²/g, in particular of approximately 5 m²/g

and wherein said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystal system, in particular said crystalline phase represents from 50 to 90% by total weight of the catalyst, preferably said crystalline phase being baddeleyite and preferably comprising a crystallite size of 15 to 100 nm.

Specific surface area

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst has a surface area, analyzed by BET, of 1 to 50 m²/g.

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst has a surface area, analyzed by BET, of 1 to 10 m²/g, preferably approximately 5 m²/g.

Structure

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, in which said crystalline phase represents from 50 to 90% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, in which said crystalline phase is baddeleyite.

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, in which the zirconium dioxide ZrO ₂ catalyst support comprises impurities such as Hafnium (Hf), Rhenium (Re) and Silicon (Si) atoms.

Advantageously, the mass percentage ratio between Hafnium atoms and zirconium atoms (Hf/Zr) is less than 5%.

Advantageously, the mass percentage ratio between Rhenium atoms and zirconium atoms (Re/Zr) is less than 5%.

Advantageously, the mass percentage ratio between the silicon atoms and the zirconium atoms (Si/Zr) is less than 2%.

According to a particular embodiment, the invention relates to a Cu-M / ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst has a microstructure whose crystallite size is from 15 to 100 nm, preferably from 15 to 50 nm.

• ledit catalyseur possède une aire de surface, analysée par BET, de 1 à 250 m²/g, en particulier de 1 à 50 m²/g, de préférence de 1 à 10 m²g,
• et ledit catalyseur comporte une phase cristalline, analysée par diffraction des RX, cristallisée dans un système cristallin monoclinique.

According to a particular embodiment, the invention relates to a Cu-M / ZrO ₂ bimetallic supported catalyst as defined above, in which:

• said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, in particular of 1 to 50 m²/g, preferably of 1 to 10 m²g,
• and said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system.

• ledit catalyseur possède une aire de surface, analysée par BET, de 1 à 10 m²/g,
• et ledit catalyseur comporte une phase cristalline, analysée par diffraction des RX, cristallisée dans la baddeleyite monoclinique dont la taille des cristallites est de 15 à 100 nm, de préférence de 15 à 50 nm.
• et comprenant des impuretés telles que des atomes d’Hafnium (Hf), de Rhénium (Re) et du Silicium (Si).

According to a particular embodiment, the invention relates to a Cu-M / ZrO ₂ bimetallic supported catalyst as defined above, in which:

• said catalyst has a surface area, analyzed by BET, of 1 to 10 m²/g,
• and said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in monoclinic baddeleyite whose crystallite size is from 15 to 100 nm, preferably from 15 to 50 nm.
• and including impurities such as Hafnium (Hf), Rhenium (Re) and Silicon (Si) atoms.

According to a particular embodiment, the invention relates to a Cu-M/ZrO ₂ bimetallic supported catalyst as defined above, comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a zirconium dioxide support, of formula Cu-M/ZrO ₂ ,

wherein said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, preferably of 1 to 50 m²/g, preferentially of 1 to 10 m²/g, in particular of approximately 5 m²/g

and wherein said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystal system, in particular said crystalline phase represents from 50 to 90% by total weight of the catalyst, preferably said crystalline phase being baddeleyite and preferably comprising a crystallite size of 15 to 100 nm.

Composition

According to a particular embodiment, the invention relates to a Cu-M/Support bimetallic supported catalyst as defined above, in which said catalyst comprises a total content of the bimetallic elements copper and metal M, M being chosen from Mn, Co, Ni and Fe, of 0.5 to 25% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a Cu-M/Support bimetallic supported catalyst as defined above, in which said catalyst comprises a total content of the bimetallic elements copper and metal M, M being chosen from Mn, Co, Ni and Fe, of 5 to 20% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a Cu-M/Support bimetallic supported catalyst as defined above, in which the total content of the copper element is from 1 to 25% by total weight of the catalyst, preferably from 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a Cu-M/Support bimetallic supported catalyst as defined above, in which the total content of the metal element M, M being chosen from Mn, Co, Ni and Fe, is from 1 to 25% by total weight of the catalyst, preferably from 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a Cu-M/Support bimetallic supported catalyst as defined above, in which the weight ratio between the metal M and the copper varies from 1:1 to 1:10, preferably 1:2.

Cu-Mn /Support, ZrO ₂ or Al ₂ O ₃ : Degree of oxidation of Mn and Cu on the surface

According to a particular embodiment, the invention relates to a CuMn/Support bimetallic supported catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of copper element at an oxidation state (II) and/or in which the manganese element is present at oxidation states (II), (III) and (IV).

According to a particular embodiment, the invention relates to a CuMn/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of copper element at an oxidation state (II) and/or manganese element at an oxidation state (II).

According to a particular embodiment, the invention relates to a CuMn/γ-Al ₂ O ₃ bimetallic supported catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of copper element at an oxidation state (II) and/or manganese element at an oxidation state (III).

CuCo / ZrO ₂ : Degree of oxidation of Co and Cu on the surface

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of copper element at an oxidation state (II) and/or cobalt element at an oxidation state (II).

Advantageously, in certain cases a CuCo/ZrO ₂ bimetallic catalyst in which the majority of the copper and cobalt elements are already present in the oxidized state possibly makes it possible to use said catalyst without prior reduction of the copper and cobalt elements of the catalyst before carrying out the hydrogenation reaction of the oxamides or oxamates in ethylene glycol. This also makes it possible to avoid storing the catalysts in an inert atmosphere to avoid oxidation of the copper and cobalt atoms.

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of copper element at an oxidation state (II) and more than 50% of cobalt element at an oxidation state (II).

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has an amount of more than 70 mol% of copper element at an oxidation state (II) and more than 65% of cobalt element at an oxidation state (II).

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has an amount of more than 50 mol% of element copper at an oxidation state (II) in the form of CuO and more than 50% of element cobalt at an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has an amount greater than 70 mol% of element copper at an oxidation state (II) in the form of CuO and an amount greater than 65 mol% of element cobalt at an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has:

- a quantity of 10 to 30 mol% of copper element in the metallic state at an oxidation state (0) or at an oxidation state (I) in the form of Cu ₂ O

-and a quantity of 10 to 35 mol% of cobalt element in the metallic state at an oxidation state (0).

• une quantité supérieure à 70% molaire d’élément cuivre à un degré d’oxydation (II) sous forme de CuO,
• une quantité de 10 à 30% molaire d’élément cuivre à l’état métallique à un degré d’oxydation (0) ou à un degré d’oxydation (I) sous forme de Cu₂O
• une quantité de 10 à 35% molaire d’élément cobalt à l’état métallique à un degré d’oxydation (0),
• et une quantité supérieure à 65% molaire d’élément cobalt à un degré d’oxydation (II) sous forme de Co₂O₃ou Co(OH)₂.

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has:

• an amount greater than 70 mol% of the element copper in oxidation state (II) in the form of CuO,
• an amount of 10 to 30 mol% of the element copper in the metallic state at an oxidation state (0) or at an oxidation state (I) in the form of Cu ₂ O
• an amount of 10 to 35 mol% of the element cobalt in the metallic state at an oxidation state (0),
• and an amount greater than 65 mol% of the element cobalt in an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has:

- a quantity of more than 50 mol% of the element copper at oxidation state (II) and more than 50% of the element cobalt at oxidation state (II),

- a specific surface area of 1 to 50 m²/g

- a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system.

• une quantité supérieure à 70% molaire d’élément cuivre à un degré d’oxydation (II) sous forme de CuO,
• une quantité de 10 à 30% molaire d’élément cuivre à l’état métallique à un degré d’oxydation (0) ou à un degré d’oxydation (I) sous forme de Cu₂O
• une quantité de 10 à 35% molaire d’élément cobalt à l’état métallique à un degré d’oxydation (0),
• une quantité supérieure à 65% molaire d’élément cobalt à un degré d’oxydation (II) sous forme de Co₂O₃ou Co(OH)₂.
• une surface spécifique de 1 à 50 m²/g, en particulier de 1 à 10 m²/g analysée par BET,
• et une phase cristalline, analysée par diffraction des RX, cristallisée dans un système cristallin monoclinique, notamment de la baddeleyite, en particulier comprenant des impuretés d’Hafnium, de Rhénium et de Silicium.

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ catalyst as defined above, in which said catalyst has:

• an amount greater than 70 mol% of the element copper in oxidation state (II) in the form of CuO,
• an amount of 10 to 30 mol% of the element copper in the metallic state at an oxidation state (0) or at an oxidation state (I) in the form of Cu ₂ O
• an amount of 10 to 35 mol% of the element cobalt in the metallic state at an oxidation state (0),
• an amount greater than 65 mol% of the element cobalt in an oxidation state (II) in the form of Co ₂ O ₃ or Co(OH) ₂ .
• a specific surface area of 1 to 50 m²/g, in particular 1 to 10 m²/g analyzed by BET,
• and a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system, in particular baddeleyite, in particular comprising impurities of Hafnium, Rhenium and Silicon.

Cu-M/ZrO ₂ catalyst morphology

According to a particular embodiment, the invention relates to a Cu-M / ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst is in the form of micrometric particles of 1 to 500 µm, preferably in the form of a population of particles of rounded morphology.

Cu-Mn / ZrO ₂ catalyst morphology

According to a particular embodiment, the invention relates to a Cu-Mn/ _ZrO2 bimetallic supported catalyst as defined above, in which said catalyst is in the form of micrometric particles of 1 to 500 µm, preferably in the form of a population of particles of rounded morphology.

CuCo/ _ZrO2 catalyst morphology

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst is in the form of micrometric particles of 1 to 500 µm.

As a non-limiting example, morphology and average size can be assessed by scanning electron microscopy (SEM).

Micrometric sizes allow easier handling of the catalyst.

According to a particular embodiment, the invention relates to a CuCo/ZrO ₂ bimetallic supported catalyst as defined above, in which said catalyst comprises a total content of the bimetallic elements copper and cobalt of 0.5 to 25% by total weight of the catalyst, preferably the weight ratio between cobalt and copper varies from 1:1 to 1:10, preferentially from 1:1 to 1:5,

and/or wherein said catalyst has an amount of more than 50 mol% of element copper at oxidation state (II) and/or element cobalt at oxidation state (II),

and/or wherein said catalyst is in the form of a population of micrometric particles of 1 to 500 µm, preferably in the form of a population of particles of rounded morphology.

Cu-Mn / γ-Al catalyst morphology ₂ O ₃

According to a particular embodiment, the invention relates to a Cu-Mn/γ-Al ₂ O ₃ bimetallic supported catalyst as defined above, in which said catalyst is in the form of micrometric particles of 1 to 500 µm, preferably in the form of a population of particles of rounded morphology.

Process for the preparation of ethylene glycol

• une étape d’hydrogénation par de l’hydrogène d’un composé oxamide ou oxamate, en éthylène glycol, en présence d’un catalyseur supporté bimétallique comprenant du cuivre et un métal M choisi parmi le manganèse, le cobalt, le nickel et le fer, sur un support, de formule Cu-M / Support, dans laquelle M représente Mn, Co, Ni ou Fe.

A third subject of the invention relates to a process for preparing ethylene glycol comprising:

• a step of hydrogenation by hydrogen of an oxamide or oxamate compound, into ethylene glycol, in the presence of a bimetallic supported catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe.

According to a particular embodiment, the invention relates to a preparation method as defined above, in which the support is chosen from an oxide, in particular zirconium dioxide (ZrO ₂ ) and γ-alumina (γ-Al ₂ O ₃ ).

According to a particular embodiment, the invention relates to a preparation process as defined above, in which said oxamide compound is of the following Formula 1:

• un atome d’hydrogène,

• un groupement alkyle en C₁à C₂₀, linéaire ou ramifié,
• un groupement alcényle en C₂à C₂₀, linéaire ou ramifié,
• un groupement aryle ou hétéroaryle en C₃à C_20,
• un groupement alkyl-aryle ou alkyl-hérétoaryle en C₅à C₂₀,
• un groupement cycloalkyle en C₃à C₁₀,

in which R _a and R _b represent independently of each other:

• a hydrogen atom,

• a linear or branched _C1 to _C20 alkyl group,
• a linear or branched _C2 to _C20 alkenyl group,
• a _C3 to C20 aryl or heteroaryl group _,
• a _C5 to _C20 alkyl-aryl or alkyl-heretoaryl group,
• a _C3 to _C10 cycloalkyl group,

at least one of the groups R _a or R _b being other than hydrogen,

R _a and R _b can form a cycle.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above in which said oxamide compound is chosen from oxamides prepared with diethylamine, piperidine, pyrrolidine, morpholine and aniline, preferably piperidine.

According to a particular embodiment, the invention relates to a preparation process as defined above, in which said oxamate compound is of the following Formula 2,

• un atome d’hydrogène,

• un groupement alkyle en C₁à C₂₀, linéaire ou ramifié,
• un groupement alcényle en C₂à C₂₀, linéaire ou ramifié
• un groupement hétéroalkyle en C₁à C₂₀, linéaire ou ramifié, ,
  • un groupement aryle ou hétéroaryle en C₃à C₂₀
  • un groupement alkyl-aryle ou alkyl-hérétoaryle en C₅à C₂₀,
  • un groupement cycloalkyle en C₃à C₁₀,

in which R _a and R _b represent independently of each other:

• a hydrogen atom,

• a linear or branched _C1 to _C20 alkyl group,
• a linear or branched _C2 to _C20 alkenyl group
• a linear or branched _C1 to _C20 heteroalkyl group,
  • a _C3 to _C20 aryl or heteroaryl group
  • a _C5 to _C20 alkyl-aryl or alkyl-heretoaryl group,
  • a _C3 to _C10 cycloalkyl group,

at least one of the groups R _a or R _b being other than hydrogen,

R _a and R _b can be covalently linked and form a cycle,

• alkyle en C₁à C₁₀, linéaire ou ramifié, et
• cycloalkyle en C₃à C_10,
• un groupement aryle ou héréroaryle en C₃à C₂₀

• un groupement alkyl-aryle ou alkyl-hétéroaryle en C₅à C₂₀.

in which R _c represents a group chosen from:

• _C1 - _C10 alkyl, linear or branched, and
• C ₃ to C _{10 cycloalkyl,}
• a _C3 to _C20 aryl or heteroaryl group

• a _C5 to _C20 alkyl-aryl or alkyl-heteroaryl group.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et un métal M choisi parmi le manganèse, le cobalt, le nickel et le fer, sur un support, de formule Cu-M / Support, dans laquelle M représente Mn, Co, Ni ou Fe,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et un métal M choisi parmi le manganèse, le cobalt, le nickel et le fer, sur un support, de formule Cu-M / Support, dans laquelle M représente Mn, Co, Ni ou Fe,
• d’une base
• d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe,
• from a base
• of a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et un métal M choisi parmi le manganèse, le cobalt, le nickel et le fer, sur un support, de formule Cu-M / Support, dans laquelle M représente Mn, Co, Ni ou Fe,
• d’une base
• d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe,
• from a base
• of a solvent,

• un chauffage dudit milieu réactionnel,

to obtain a reaction medium,

• heating of said reaction medium,

to obtain ethylene glycol.

Cu-Mn / Support, ZrO ₂ or γ-Al ₂ O ₃

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du manganèse sur un support, de formule Cu-Mn / Support,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and manganese on a support, of formula Cu-Mn / Support,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du manganèse sur un support en oxyde, de formule Cu-Mn / oxyde,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and manganese on an oxide support, of formula Cu-Mn/oxide,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du manganèse sur un support en dioxyde de zirconium, de formule Cu-Mn / ZrO₂,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and manganese on a zirconium dioxide support, of formula Cu-Mn / ZrO ₂ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du manganèse sur un support en alumine γ, de formule Cu-Mn / γ-Al₂O₃,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and manganese on a γ-alumina support, of formula Cu-Mn / γ-Al ₂ O ₃ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

Cu-Co / Support, ZrO ₂ or γ-Al ₂ O ₃

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du cobalt sur un support, de formule Cu-Co / Support,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and cobalt on a support, of formula Cu-Co / Support,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du cobalt sur un support en oxyde, de formule Cu-Co / oxyde,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and cobalt on an oxide support, of formula Cu-Co/oxide,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du cobalt sur un support en dioxyde de zirconium, de formule Cu-Co / ZrO₂,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and cobalt on a zirconium dioxide support, of formula Cu-Co / ZrO ₂ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du cobalt sur un support en alumine γ, de formule Cu-Co / γ-Al₂O₃,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and cobalt on a γ-alumina support, of formula Cu-Co / γ-Al ₂ O ₃ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

Cu-Ni / Support, ZrO ₂ or γ-Al ₂ O ₃

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du nickel sur un support, de formule Cu-Ni / Support,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and nickel on a support, of formula Cu-Ni / Support,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du nickel sur un support en oxyde, de formule Cu-Ni / oxyde,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and nickel on an oxide support, of formula Cu-Ni/oxide,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du nickel sur un support en dioxyde de zirconium, de formule Cu-Ni / ZrO₂,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and nickel on a zirconium dioxide support, of formula Cu-Ni / ZrO ₂ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du nickel sur un support en alumine γ, de formule Cu-Ni / γ-Al₂O₃,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and nickel on a γ-alumina support, of formula Cu-Ni / γ-Al ₂ O ₃ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

Cu-Fe / Support, ZrO ₂ or γ-Al ₂ O ₃

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du fer sur un support, de formule Cu-Fe / Support,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and iron on a support, of formula Cu-Fe / Support,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du fer sur un support en oxyde, de formule Cu-Fe / oxyde,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and iron on an oxide support, of formula Cu-Fe/oxide,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du fer sur un support en dioxyde de zirconium, de formule Cu-Fe / ZrO₂,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and iron on a zirconium dioxide support, of formula Cu-Fe / ZrO ₂ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

• l’étape d’hydrogénation comprend
  • la mise en contact :

• dudit composé oxamide ou oxamate,
• du dihydrogène,
• dudit catalyseur bimétallique supporté comprenant du cuivre et du fer sur un support en alumine γ, de formule Cu-Fe / γ-Al₂O₃,
• éventuellement d’un base
• éventuellement d’un solvant,

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which:

• The hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and iron on a γ-alumina support, of formula Cu-Fe / γ-Al ₂ O ₃ ,
• possibly from a base
• possibly a solvent,

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol.

Process for the preparation of ethylene glycol with conditions on the catalyst used

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said catalyst is according to the catalyst of the invention as defined above.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said catalyst is prepared by mixing the support in powder form and an aqueous solution of copper and cobalt salts, followed by calcination.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said catalyst is prepared by mixing the support in powder form and an aqueous solution of copper and cobalt salts, without adding additives or surfactants, followed by calcination.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel du métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dans un volume d’eau de 5 à 10 mL, sur un support sous forme de poudre, en particulier du dioxyde de zirconium ou de l’alumine γ, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

Advantageously, the Cu-M/Support catalyst used in the process as defined above is prepared according to a preparation process comprising the following steps:

• a step A of impregnation of a copper salt and a salt of the metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, in a volume of water of 5 to 10 mL, on a support in powder form, in particular zirconium dioxide or γ-alumina, with a mass of the solution/mass of support ratio of from 0.6 to 1.0;

• une étape B de séchage dudit mélange homogène, pour obtenir le catalyseur Cu-M / Support sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination dudit mélange homogène sec pour obtenir ledit catalyseur.

to obtain the Cu-M catalyst / Support in the form of a homogeneous mixture,

• a step B of drying said homogeneous mixture, to obtain the Cu-M catalyst / Support in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination of said dry homogeneous mixture to obtain said catalyst.

Advantageously, in impregnation step A, said aqueous solution containing the salts of copper and of the metal M, M being chosen from Mn, Co, Ni and Fe, is free of additive and surfactant. In other words, said aqueous impregnation solution consists of a demineralized solution of water in which the salts of said metal M and of copper are dissolved.

Advantageously the salt of the metal M is a nitrate salt and the copper salt is copper nitrate.

The process for preparing ethylene glycol as defined above according to the invention is therefore implemented with a catalyst prepared with an aqueous solution, advantageously free of additives and surfactants, which makes it more industrializable and at lower cost.

With Cu-M/ZrO catalyst ₂

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said Cu-M / ZrO ₂ catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, in particular of 1 to 50 m²/g, preferably of 1 to 10 m²/g, preferentially approximately 5 m²/g.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said Cu-M / ZrO ₂ catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system, in particular baddeleyite,

optionally wherein said crystalline phase of the Cu-M/ _ZrO2 catalyst represents from 50 to 90% by total weight of the catalyst,

possibly the size of the crystallites of said crystalline phase is 15 to 40 nm.

Conditions of the process for the preparation of ethylene glycol

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which said catalyst is used in a proportion of 0.1 to 10 mmol of copper, in particular in a proportion of 4 mmol of Cu.

The 0.1 to 10 mmol range includes the following ranges: 0.1 to 0.5 mmol, 0.5 to 1 mmol, 1 to 2 mmol, 2 to 3 mmol, 3 to 4 mmol.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the oxamide or oxamate compound is used in a proportion of 2 to 400 molar equivalents, in particular in a proportion of 5 equivalents, relative to the metal Cu.

The range of 2 to 400 molar equivalents (eq.) includes the following ranges: 2 to 3 eq., 3 to 4 eq., 4 to 5 eq., 5 to 10 eq., 10 to 50 eq., 50 to 100 eq., 100 to 200 eq., 200 to 300 eq., 300 to 400 eq.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the dihydrogen is used under a pressure of 2 to 10 MPa, in particular 6 MPa.

The expression MPa corresponds to 10 ⁶ Pascal and is equivalent to 10 bars.

The expression “from 2.0 to 10.0 MPa” corresponds to the ranges: from 2.0 to 2.5 MPa; from 2.5 to 3.0 MPa; from 3.0 to 3.5 MPa; from 3.5 to 4.0 MPa; from 4.0 to 4.5 MPa; from 4.5 to 5.0 MPa; from 5.0 to 5.5 MPa; from 5.5 to 6.0 MPa; from 6.0 to 6.5 MPa; from 6.5 to 7.0 MPa; from 7.0 to 7.5 MPa; from 7.5 to 8.0 MPa; from 8.0 to 8.5 MPa; from 8.5 to 9.0 MPa; from 9.0 to 9.5 MPa; from 9.5 to 10 MPa.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the solvent is chosen from dioxane, xylene, mesitylene, tetrahydrofuran (THF), 2-methyltetrahydrofuran, toluene, in particular THF.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the reaction medium is placed under a pressure of 2 to 10 MPa, in particular 6 MPa.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the reaction medium is heated to a temperature of from 100 to 250°C, in particular from 180 to 200°C.

The 100 to 250°C range includes the following ranges: 100 to 110°C, 110 to 120°C, 120 to 130°C, 130 to 140°C, 140 to 150°C, 150 to 160°C, 160 to 170°C, 170 to 180°C, 180 to 190°C, 190 to 200°C, 200 to 210°C, 210 to 220°C, 220 to 230°C, 230 to 240°C, 240 to 250°C.

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the reaction medium is heated for 5 to 24 hours, in particular 8 or 16 hours.

Process conditions in flow

Without limitation, the method according to the invention can be implemented in a flow chemistry apparatus, for example in commercial reactors such as “H-Cube Pro®” or “Phoenix®” from the company ThalesNano INC. (7 Zahony Street, Graphisoft Park, Building D, H-1031 Budapest, Hungary) or such as the “E-Series” or “R-Series flow chemistry systems” reactors from the company Vapourtec Ltd (Unit 21/Park Farm Business Centre/Fornham Pk, Bury Saint Edmunds IP28 6TS, United Kingdom).

Advantageously, the continuous flow process is carried out at a temperature of 100°C to 250°C.

Advantageously, the continuous flow process is carried out at a pressure of 0.1 MPa to 10 MPa.

According to a particular embodiment, the continuous flow process is carried out in a reactor in which the gases represent 10 to 90% of the volume of the reactor.

The expression “10 to 90%” corresponds to the following ranges: 10 to 20%; 20 to 30%; 30 to 40%; 40 to 50%; 50 to 60%; 60 to 70%; 70 to 80%; 80 to 90%.

According to a particular embodiment, the continuous flow process is carried out by means allowing a contact time between the reagents of 1 second to 2 hours, in particular of 1 second to 2 minutes.

The expression "1 second to 2 hours" corresponds to the ranges: 1 to 15 seconds; 15 to 30 seconds; 30 seconds to 1 minute; 1 to 2 minutes; 2 to 15 minutes; 15 to 30 minutes; 30 minutes to 1 hour; 1 to 2 hours.

According to a particular embodiment, the hydrogenation reaction step of the process is carried out in continuous flow and comprises means for introducing into the reactor the flow of hydrogen in contact with the substrate (oxamide or oxamate).

According to a particular embodiment, the invention relates to a process for preparing ethylene glycol as defined above, in which the substrate, namely the oxamide or the oxamate or their mixture, circulates under flow and/or the dihydrogen circulates under flow, through or in contact with said catalyst.

Process for the preparation of the catalyst

• une étape A d’imprégnation d’un sel de cuivre et d’un sel d’un métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

A fourth object of the invention relates to a process for preparing a Cu-M/Support catalyst, comprising:

• a step A of impregnation of a copper salt and a salt of a metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a support in powder form, with a mass of the solution / mass of support ratio of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-M / Support sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-M / Support.

to obtain the Cu-M catalyst / Support in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M catalyst / Support in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-M/Support catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel d’un métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en oxyde sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-M/oxide catalyst, comprising:

• a step A of impregnation of a copper salt and a salt of a metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on an oxide support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-M / Support sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-M / Support.

to obtain the Cu-M catalyst / Support in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M catalyst / Support in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-M/Support catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel d’un métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en dioxyde de zirconium sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-M / ZrO ₂ catalyst, comprising:

• a step A of impregnation of a copper salt and a salt of a metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a zirconium dioxide support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

to obtain the Cu-M/ZrO ₂ catalyst in the form of a homogeneous mixture,

said support

having a surface area of 1 to 250 m²/g, in particular 1 to 50 m²/g, preferably 1 to 10 m²/g

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-M/ZrO₂sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur.

and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M/ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said catalyst.

• une étape A d’imprégnation d’un sel de cuivre et de manganèse, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en dioxyde de zirconium sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Mn / ZrO ₂ catalyst, comprising:

• a step A of impregnation of a copper and manganese salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a zirconium dioxide support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

to obtain the Cu-Mn/ZrO ₂ catalyst in the form of a homogeneous mixture,

said support

having a surface area of 1 to 250 m²/g, in particular 1 to 50 m²/g, preferably 1 to 10 m²/g

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Mn/ZrO₂sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur.

and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Mn/ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said catalyst.

• une étape A d’imprégnation d’un sel de cuivre et de cobalt, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en dioxyde de zirconium sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Co / ZrO ₂ catalyst, comprising:

• a step A of impregnation of a copper and cobalt salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a zirconium dioxide support in powder form, with a mass ratio of the solution / mass of the support of from 0.6 to 1.0;

to obtain the Cu-Co/ZrO ₂ catalyst in the form of a homogeneous mixture,

said support

having a surface area of 1 to 250 m²/g, in particular 1 to 50 m²/g, preferably 1 to 10 m²/g

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Co/ZrO₂sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur.

and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Co/ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said catalyst.

• une étape A d’imprégnation d’un sel de cuivre et de nickel, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en dioxyde de zirconium sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Ni / ZrO ₂ catalyst, comprising:

• a step A of impregnation of a copper and nickel salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a zirconium dioxide support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

to obtain the Cu-Ni/ZrO ₂ catalyst in the form of a homogeneous mixture,

said support

having a surface area of 1 to 250 m²/g, in particular 1 to 50 m²/g, preferably 1 to 10 m²/g

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Ni/ZrO₂sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur.

and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Ni/ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said catalyst.

• une étape A d’imprégnation d’un sel de cuivre et de fer, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en dioxyde de zirconium sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Fe/ _ZrO2 catalyst, comprising:

• a step A of impregnation of a copper and iron salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a zirconium dioxide support in powder form, with a mass ratio of the solution / mass of the support of from 0.6 to 1.0;

to obtain the Cu-Fe/ZrO ₂ catalyst in the form of a homogeneous mixture,

said support

having a surface area of 1 to 250 m²/g, in particular 1 to 50 m²/g, preferably 1 to 10 m²/g

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Fe/ZrO₂sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur.

and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Fe/ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel d’un métal M, M étant choisi parmi Mn, Co, Ni et Fe, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en alumine γ-Al₂O₃sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-M / γ-Al ₂ O ₃ catalyst, comprising:

• a step A of impregnation of a copper salt and a salt of a metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a γ-Al ₂ O ₃ alumina support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-M / γ-Al₂O₃sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-M / γ-Al₂O₃.

to obtain the Cu-M / γ-Al ₂ O ₃ catalyst in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M / γ-Al ₂ O ₃ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-M / γ-Al ₂ O ₃ catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel de manganèse, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en alumine γ-Al₂O₃sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Mn / γ-Al ₂ O ₃ catalyst, comprising:

• a step A of impregnation of a copper salt and a manganese salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a γ-Al ₂ O ₃ alumina support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Mn / γ-Al₂O₃sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-Mn / γ-Al₂O₃.

to obtain the Cu-Mn / γ-Al ₂ O ₃ catalyst in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Mn / γ-Al ₂ O ₃ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-Mn / γ-Al ₂ O ₃ catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel de cobalt, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en alumine γ-Al₂O₃sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Co / γ-Al ₂ O ₃ catalyst, comprising:

• a step A of impregnation of a copper salt and a cobalt salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a γ-Al ₂ O ₃ alumina support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Co / γ-Al₂O₃sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-Co / γ-Al₂O₃.

to obtain the Cu-Co / γ-Al ₂ O ₃ catalyst in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Co / γ-Al ₂ O ₃ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-Co / γ-Al ₂ O ₃ catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel de nickel, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en alumine γ-Al₂O₃sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Ni / γ-Al ₂ O ₃ catalyst, comprising:

• a step A of impregnation of a copper salt and a nickel salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a γ-Al ₂ O ₃ alumina support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Ni / γ-Al₂O₃sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-Ni / γ-Al₂O₃.

to obtain the Cu-Ni / γ-Al ₂ O ₃ catalyst in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Ni / γ-Al ₂ O ₃ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-Ni / γ-Al ₂ O ₃ catalyst.

• une étape A d’imprégnation d’un sel de cuivre et d’un sel de fer, dissous dans une solution aqueuse, dépourvue d’additif et de surfactant, dans un volume d’eau de 5 à 10 mL, sur un support en alumine γ-Al₂O₃sous forme de poudre, avec un rapport masse de la solution / masse de support compris de 0,6 à 1,0 ;

According to a particular embodiment, the invention relates to a process for preparing a Cu-Fe / γ-Al ₂ O ₃ catalyst, comprising:

• a step A of impregnation of a copper salt and an iron salt, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a γ-Al ₂ O ₃ alumina support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0;

• une étape B de séchage dudit matériau homogène, à une température de 60 à 100°C, pendant une durée de 10 à 24 heures, pour obtenir le catalyseur Cu-Fe / γ-Al₂O₃sous forme d’un mélange homogène sec,
• une étape C d’activation, comprenant une calcination sous air dudit mélange homogène sec à une température de 200 à 1000°C, pendant une durée de 1 à 15 heures, pour obtenir ledit catalyseur Cu-Fe / γ-Al₂O₃.

to obtain the Cu-Fe / γ-Al ₂ O ₃ catalyst in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-Fe / γ-Al ₂ O ₃ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-Fe / γ-Al ₂ O ₃ catalyst.

According to a particular embodiment, the invention relates to a process as defined above for preparing a catalyst according to the invention, in which in step A, said salt of the metal M is a nitrate salt and/or said copper salt is copper nitrate.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a catalyst according to the invention, in which in step A, said support is used in a proportion of 1 to 50 ranges.

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-M/Support catalyst according to the invention, in which in step A, the total mass content of the bimetallic elements copper and metal M is from 0.5 to 25% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-M/Support catalyst according to the invention, in which in step A, the total mass content of the bimetallic elements copper and metal M is from 5 to 20% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-M/Support catalyst according to the invention, in which in step A, the total mass content of the copper element is from 1 to 25% by total weight of the catalyst, preferably from 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-M/Support catalyst according to the invention, in which in step A, the total mass content of the metal element M is from 1 to 25% by total weight of the catalyst, preferably from 1 to 10% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-M/Support catalyst according to the invention, in which in step A, the weight ratio between the metal M and the copper varies from 1:1 to 1:10, in particular from 2:10 to 5:10.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/Support catalyst according to the invention, in which in step B, said homogeneous mixture is dried at 80°C for 16 hours.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/Support catalyst according to the invention, in which in step C, said dry homogeneous mixture is calcined at 600°C for 2 hours.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/ZrO ₂ catalyst according to the invention, in which in step A, said support used has a surface area, analyzed by BET, of 1 to 50 m²/g.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a catalyst according to the invention, in which in step A, said support used for the Cu-M/ZrO ₂ catalyst has a surface area, analyzed by BET, of 1 to 10 m²/g, preferably of 5 to 7 m²/g.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/ZrO ₂ catalyst according to the invention, in which in step A, said support used has a crystalline phase representing from 50 to 90% by total weight of the catalyst.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/ZrO ₂ catalyst according to the invention, in which in step A, said support used comprises baddeleyite.

According to a particular embodiment, the invention relates to a process as defined above for the preparation of a Cu-M/ZrO ₂ catalyst according to the invention, in which in step A, said support used comprises baddeleyite whose crystallite size is from 15 to 100 nm, preferably from 15 to 50 nm, and optionally comprising impurities of Hafnium (Hf), Rhenium (Re) and silicon (Si).

According to a particular embodiment, the invention relates to a process as defined above for preparing a Cu-Co/ZrO ₂ catalyst according to the invention, in which in step A, the support is in the form of micrometric particles of 1 to 500 µm.

Catalysts prepared according to the process of the invention

A fifth subject of the present invention relates to a bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a support, of formula Cu-M / Support, capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on an oxide support, of formula Cu-M / oxide, capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a zirconium dioxide support, of formula Cu-M / ZrO ₂ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and manganese on a zirconium dioxide support, of formula Cu-Mn / ZrO ₂ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and cobalt on a zirconium dioxide support, of formula Cu-Co / ZrO ₂ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and nickel on a zirconium dioxide support, of formula Cu-Ni / ZrO ₂ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and iron on a zirconium dioxide support, of formula Cu-Fe / ZrO ₂ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a γ-Al ₂ O ₃ alumina support of formula Cu-M / γ-Al ₂ O ₃ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and manganese on a γ-Al ₂ O ₃ alumina support of formula Cu-Mn / γ-Al ₂ O ₃ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and cobalt on a γ-Al ₂ O ₃ alumina support of formula Cu-Co / γ-Al ₂ O ₃ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and nickel on a γ-Al ₂ O ₃ alumina support of formula Cu-Ni / γ-Al ₂ O ₃ , capable of being obtained by the process for preparing a catalyst as defined above.

According to a particular embodiment, the present invention relates to a bimetallic supported catalyst comprising copper and iron on a γ-Al ₂ O ₃ alumina support of formula Cu-Fe / γ-Al ₂ O ₃ , capable of being obtained by the process for preparing a catalyst as defined above.

Use of the catalyst for the hydrogenolysis of ethylene glycol or for depolymerizing biomass

Another subject of the present invention relates to the use of a catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, for the hydrogenolysis of ethylene glycol.

Another object of the present invention relates to the use of a Cu-M/Support catalyst according to the invention as defined above, for the hydrogenolysis of ethylene glycol.

The inventors have surprisingly observed that the Cu-M/Support catalyst according to the invention makes it possible to catalyze the hydrogenation reaction of oxamides or oxamates to ethylene glycol but also the hydrogenolysis of ethylene glycol present in the mixture resulting from the hydrogenation reaction of oxamides or oxamates. The modifications of the conditions with parameters such as temperature, make it possible to modulate by promoting in particular the hydrogenation reaction of oxamides or oxamates.

For the purposes of the present invention, the term “hydrogenolysis” means the cleavage reaction of at least one carbon-carbon (C-C) or carbon-heteroatom covalent bond such as the carbon-oxygen bond, by the action of hydrogen.

• une étape de mise en contact de l’éthylène glycol en présence d’hydrogène et d’un catalyseur supporté bimétallique hétérogène comprenant du cuivre et un métal M, M étant choisi parmi Mn, Co, Ni et Fe, sur un support, de formule Cu-M / Support tel que défini ci-dessus.

Another object of the present invention relates to a process for the hydrogenolysis of ethylene glycol comprising:

• a step of bringing ethylene glycol into contact in the presence of hydrogen and a heterogeneous bimetallic supported catalyst comprising copper and a metal M, M being chosen from Mn, Co, Ni and Fe, on a support, of formula Cu-M / Support as defined above.

• la mise en contact :

• de l’éthylène glycol,
• du dihydrogène, en particulier de 20 à 100 bars, de préférence à 60 bars
• dudit catalyseur supporté comprenant du cuivre et un métal M choisi parmi le manganèse, le cobalt, le nickel et le fer, sur un support, de formule Cu-M / Support, dans laquelle M représente Mn, Co, Ni ou Fe,
• en particulier en dioxyde de zirconium ou en alumine γ,
• éventuellement d’un solvant, en particulier le tétrahydrofurane (THF),
• éventuellement d’une base, en particulier le ter-butylate de potassium (KOtBu),

According to a particular embodiment, the invention relates to a process for the hydrogenolysis of ethylene glycol as defined above, comprising:

• contacting:

• ethylene glycol,
• dihydrogen, in particular from 20 to 100 bars, preferably 60 bars
• said supported catalyst comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe,
• in particular zirconium dioxide or γ-alumina,
• possibly a solvent, in particular tetrahydrofuran (THF),
• possibly a base, in particular potassium tert-butylate (KOtBu),

• éventuellement un chauffage dudit milieu réactionnel,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain a degradation of ethylene glycol by a cleavage of at least one carbon-carbon or carbon-oxygen covalent bond.

Another subject of the present invention relates to the use of a catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, to depolymerize the biomass.

Another object of the present invention relates to the use of a Cu-M/Support catalyst according to the invention as defined above for depolymerizing biomass.

The inventors surprisingly observed, based on ethylene glycol as a model compound, that the Cu-M/Support catalyst according to the invention could catalyze the hydrogenolysis reaction of the diol groups present in the carbohydrate molecules contained in the biomass by cleaving the carbon-carbon (C-C) or carbon-oxygen (C-O) bonds.

For the purposes of the present invention, the term "biomass" means organic matter of plant origin (including microalgae), animal, bacterial or fungal origin (fungi), usable as a source of energy (bioenergy). Biomass includes in particular carbohydrate molecules or polyols, in which diol groups -CHOH-CHOH- are present, containing covalent bonds (C-C) and (C-O).

For the purposes of the present invention, the term “depolymerizing the biomass” means the action of cleaving carbon-carbon (C-C) or carbon-heteroatom (C-X) covalent bonds, such as the carbon-oxygen (C-O) bond, of carbohydrate molecules contained in the biomass.

• une étape d’hydrogénolyse des liaisons C-C et C-O dans les groupements diols contenues dans les molécules carbohydrate contenues dans la biomasse, en présence d’un catalyseur supporté bimétallique comprenant du cuivre et un métal M choisi parmi Mn, Co, Ni et Fe, sur un support, en particulier en oxyde, de préférence en dioxyde de zirconium ou en alumine γ, de formule Cu-M / Support tel que défini ci-dessus.

Another object of the invention relates to a process for degrading biomass comprising:

• a step of hydrogenolysis of the CC and CO bonds in the diol groups contained in the carbohydrate molecules contained in the biomass, in the presence of a bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a support, in particular made of oxide, preferably zirconium dioxide or γ-alumina, of formula Cu-M / Support as defined above.

The following examples and figures illustrate the invention, without limiting its scope.

represents the X-ray powder diffractogram of a ZrO ₂ support which was calcined at 600°C for 2 hours.

represents the X-ray powder diffractogram of a Cu(10%)Co(5%)/ZrO ₂ catalyst, with a specific surface area of approximately 5m²/g, prepared with a ZrO _{2 support.}

represents scanning electron microscopy images of a _ZrO2 support calcined at 600°C for 2 hours.

represents scanning electron microscopy images of a Cu(10%)Co(5%)/ZrO ₂ catalyst, with a specific surface area of approximately 5 m²/g, calcined at 600°C for 2 hours

represents scanning electron microscopy images of a Cu(10%)Mn(5%)/ _ZrO2 catalyst, with a specific surface area of approximately 5 m²/g, calcined at 600°C for 2 hours.

represents scanning electron microscopy images of a Cu(10%)Mn(5%)/γ- _{Al2O3 catalyst} , with a specific surface area of approximately 150 m²/g, calcined at 600°C for 2 hours.

represents the X-ray photoelectron spectrometry spectrum of a Cu-Co/ZrO catalyst₂, calcined at 600°C for 2 hours, of composition Cu at 10% and Co at 5% by weight relative to the total weight of the catalyst (spectrum A) and the X-ray photoelectron spectrometry spectrum of the support used ZrO₂for the preparation of said catalyst calcined at 600°C for 2 hours (spectrum B).

represents the X-ray photoelectron spectrometry spectrum of a Cu-Mn/ZrO catalyst₂, calcined at 600°C for 2 hours, of composition Cu at 10% and Mn at 5% by weight relative to the total weight of the catalyst (spectrum C) and the spectrum in X-ray photoelectron spectrometry of a Cu-Mn/γ-Al catalyst₂O₃, calcined at 600°C for 2 hours, of composition Cu at 10% and Mn at 5% by weight relative to the total weight of the catalyst (spectrum D).

represents the spectrum of Copper Cu2p in X-ray photoelectron spectrometry of a Cu(10%)Mn(5%) / ZrO ₂ catalyst and a Cu(10%)Mn(5%) / γ-Al ₂ O ₃ catalyst.

represents the spectrum of Manganese Mn2p in X-ray photoelectron spectrometry of a Cu(10%)Mn(5%) / ZrO ₂ catalyst and a Cu(10%)Mn(5%) / γ-Al ₂ O ₃ catalyst.

Example 1 – Materials and methods

Two different supports, one in zirconium dioxide ZrO ₂ and the second in alumina (γ-Al ₂ O ₃ ) were used for the preparation of the catalysts.

The zirconium dioxide support _ZrO2, with a specific surface area of 5 to 7 m²/g, is supplied by Sterm Chemicals (15 Rue de l'Atome, 67800 Bischheim) with reference number 93-4013.

The zirconium dioxide ZrO ₂ carrier supplied by Sterm Chemicals comprises by weight approximately 97% zirconium dioxide, 1.86% hafnium dioxide (HfO ₂ ) and trace amounts of silica (SiO ₂ ) and yttrium oxide (Y ₂ O ₃ ).

The γ-Al ₂ O ₃ support is supplied by Strem Chemicals (15 Rue de l'Atome, 67800 Bischheim) with reference 13-2525, specific surface area of approximately 185 m²/g and pore volume of 0.43 cc/g.

The _SiO2 support (40-63 mm) was supplied by VWR chemicals with reference 154425P.

Copper nitrate _{Cu(NO3)2.3H2O, cobalt nitrate (Co(NO3)2.3H2O ) , manganese ,} nickel _and iron nitrate were supplied by Fischer.

The autoclave is supplied by Parr Instrument Company.

Example 2 - General procedure for the preparation of heterogeneous Cu-M/Support catalysts

A nitrate salt of the metal M, M being selected from Mn, Co, Ni and Fe and copper nitrate Cu(NO ₃ ) ₂ .3H ₂ O were dissolved in a minimum volume of demineralized water, from 5 to 10 mL forming a solution. This solution containing the metal precursors was added to the appropriate amount of support, and was mixed at room temperature until a homogeneous material was obtained. The material was then dried at 80 °C for 16 h and then calcined at 600 °C in air for 2 h to obtain the catalyst.

Table 1 below reports the preparation conditions of the Cu-M/ZrO ₂ and Cu-M / γ-Al ₂ O ₃ catalysts prepared according to Example 2.

Table 1: Composition of the Cu-M/ZrO ₂ and Cu-M / γ-Al ₂ O ₃ catalysts prepared.

Example 3 – General procedure for heterogeneous catalysis of the hydrogenation of oxamides in a 450 mL reactor.

In a 450 mL Parr autoclave equipped with a magnetic stirrer, a heterogeneous catalyst based on copper (4 mmol Cu) and metal M, M being selected from Mn, Co, Ni and Fe, was introduced on a support, oxamide (10 mmol), a base potassium tert-butoxide (KOtBu) (2 mmol) and as solvent toluene or THF (40 to 75 mL). The reactor was sealed, and the reaction mixture was purged three times with nitrogen (5 bar), and twice with hydrogen (5 bar).

The autoclave was then pressurized with 60 bars of hydrogen. The reaction medium was then brought under stirring to a temperature of 180 to 200°C for 8h, 15h or 24h.

Once the reaction was complete, the autoclave was brought back to room temperature before being depressurized and purged three times with nitrogen (5 bars).

The final mixture obtained was diluted and then an internal standard was added (mesitylene), to calculate the yield using GC-MS.

Example 4 – Tests carried out with Cu-M / Support catalysts

The tests were carried out according to example 3 according to the following reaction scheme:

Table 2 reports the conditions of the hydrogenation tests respectively with a Cu-M catalyst / Support prepared according to Example 2. The hydrogenation yield is calculated using GC-MS, mesitylene is used as an internal standard. The conversion of oxamide corresponds to the amount of substrate that is consumed during the reaction.

Table 2: Conditions of hydrogenation tests with Cu-M/Support bimetallic catalysts and the results obtained.

Example 5 – Tests carried out – Influence of the parameters of the hydrogenation process

A) Monometallic catalyst

Table 3 reports the conditions of the hydrogenation tests with Cu/ _ZrO2 , Co/ _ZrO2 and Ni/ZrO2 monometallic catalysts respectively _. The hydrogenation yield is calculated using GC-MS, mesitylene is used as an internal standard. The conversion of oxamide corresponds to the amount of substrate that is consumed during the reaction.

These results indicate that monometallic catalysts do not allow the hydrogenation of oxamide to ethylene glycol.

Table 3: Conditions of hydrogenation tests with monometallic catalysts and the results obtained.

B) Influence of temperature and reaction time

Table 4 reports the conditions of the hydrogenation tests respectively with a Cu-Co / ZrO ₂ catalyst prepared according to Example 2. The conversion of the oxamide, corresponding to the amount of substrate which is consumed during the reaction, is calculated using GC-MS, mesitylene being used as an internal standard.

Table 4: Conditions of hydrogenation tests with Cu-Co/ _ZrO2 catalysts and the results obtained.

C) Influence of the base

Table 5 reports the conditions of the hydrogenation tests with a Cu-Co/ZrO ₂ catalyst without the introduction of a base. The yield and conversion of the oxamide are calculated using GC-MS, with mesitylene being used as an internal standard.

Table 5: Conditions of hydrogenation tests with the Cu-Co / ZrO ₂ catalyst without introduction of a base and the results obtained.

Example 6 – BET analyses of Cu-M/Support catalysts

Table 6 below shows the average specific surface area, analyzed by BET, of the Cu(10%)-Co(5%) / ZrO catalysts.₂, Cu(10%)-Mn(5%) / ZrO₂and Cu(10%)-Mn(5%) / γ-Al₂O₃ prepared according to example 2 after calcination at 600°C for 2 hours.

Table 6: Average specific surface area by BET of the catalysts

1. Analyse des phases

Example 7: Structural analysis

1. Phase analysis

The X-ray powder diffractograms of the materials (catalysts or support) were carried out with a MINIFLEX II diffractometer from Rigaku, whose X-ray radiation was emitted via a tube and a copper source (wavelength Kα 1.54 Å).

shows the X-ray diffractogram obtained for the Co(5%)Cu(10%) / ZrO2 catalyst calcined at 600°C for 2 hours, exhibiting a specific surface area of 5.4 m²/g.

shows the X-ray diffractogram obtained for the ZrO ₂ support used calcined at 600°C for 2 hours, presenting a specific surface area of 6.1 m²/g.

• le support ZrO₂(A) dans le tableau 7
• le catalyseur Cu(10%)Co(5%) / ZrO₂dans le tableau 8 ,
• le catalyseur Cu(10%) Mn(5%) / ZrO₂dans le tableau 9 ,
• le catalyseur Cu(10%) Mn (5%) / γ-Al₂O₃dans le tableau 10.

The results of the exploitation of the different diffractograms obtained are presented in tables 7 to 10 below, respectively for:

• the ZrO ₂ support (A) in Table 7
• the Cu(10%)Co(5%) / ZrO ₂ catalyst in Table 8,
• the Cu(10%) Mn(5%) / ZrO ₂ catalyst in Table 9,
• the Cu(10%) Mn(5%) / γ-Al ₂ O ₃ catalyst in Table 10.

Table 7: Phase analysis in the calcined ZrO ₂ support

Table 8: Phase analysis in the Co(5%)Cu(10%) / ZrO ₂ catalyst

Table 9: Analysis of phases in the Cu(10%) Mn(5%) / ZrO ₂ catalyst

Table 10: Analysis of phases in the catalyst Cu(10%) Mn(5%) / γ-Al ₂ O ₃

Zirconium dioxide ZrO ₂ catalysts

Diffractograms of the catalysts on zirconium dioxide show the presence of crystallized phases.

XRD analyses indicate that the baddeleyite (ZrO ₂ ) crystalline phase is present in the catalyzed ZrO ₂ , Cu(10%)Co(5%)/ZrO ₂ and Cu(10%)Mn(5%)/ZrO ₂ samples.

The diffractogram of the Co(5%)Cu(10%)/ZrO ₂ sample reveals the presence of two additional crystalline phases of Copper (I) oxide, Cu ₂ O, and Copper (II) oxide, CuO with a weak signature.

The diffractogram of the Cu(10%) Mn(5%)/ZrO ₂ sample reveals the majority presence of a crystalline phase of baddeleyite and to a lesser extent the presence of copper oxide CuO and a manganese and copper oxide CuMn ₂ O ₄ .

Catalysts on alumina Cu(10%) Mn(5%) / γ-Al ₂ O ₃

1. Cristallinité -Microstructure : Analyse de la taille de cristallite

The diffractogram of the sample Cu(10%) Mn(5%)/ γ-Al ₂ O ₃ reveals the presence of a crystalline phase of aluminum oxide close to alumina as well as crystalline phases of copper oxide CuO and a manganese and copper oxide CuMn ₂ O ₄ and manganese and aluminum oxide.

1. Crystallinity - Microstructure: Analysis of crystallite size

Crystallite size

The crystallinity of materials is characterized by the size of the crystallites.

The crystallite size was qualitatively estimated in order to compare the different _ZrO2 supports of the catalysts.

The crystallite size was evaluated according to the following Scherrer formula:

The width at half maximum was estimated using ImageJ processing software (developed by the National Institutes of Health).

Crystallite size calculations from the diffractograms of the Co(5%)Cu(10%)/ZrO ₂ catalysts are reported in the following Table 11:

Table 11: Crystallite sizes

Example 8: Morphological analysis and composition analysis

The SEM images in Figures 3 to 6 were taken using a Zeiss pressure-controlled SEM-FEG scanning microscope, making it possible to observe materials with little or no conductivity without specific preparation.

The sample was stabilized on carbon adhesive paper to allow SEM observation. It should therefore be noted that the content of the carbon element may be associated with the use of the latter.

The results of MEB observations and EDX analyses are presented in summary form below.

ZrO support ₂ calcined

MEB observations of images from the reveal the presence of several particle populations (rounded, spherical and angular morphologies). The majority population has a rounded morphology, similar to that of the Co(5%)Cu(10%)ZrO ₂ sample. These particles are composed mainly of Zirconium (Zr), Oxygen (O) and Carbon (C) with traces of Rhenium (Re), Hafnium (Hf) and Silicon (Si).

The secondary population presenting a spherical morphology is composed mainly of Zirconium (Zr), Oxygen (O) and Carbon (C), with a minor amount of Hafnium (Hf) and Rhenium (Re) with traces of Silicon (Si).

Quantification was performed by EDX spectrum analysis on two areas of the particles of the support calcined at 600°C for two hours. The results expressed in mass percentage are shown in Table 12.

Table 12: Chemical composition by EDX of the ZrO ₂ support

Catalyst Co(5%)Cu(10%) /ZrO ₂

Observations of MEB images of the reveal the presence of a population of particles with a rounded morphology similar to that of the calcined ZrO ₂ support. These particles are composed mainly of Zirconium (Zr), Copper (Cu), Oxygen (O), Carbon (C) and Cobalt (Co), with a minor amount of Hafnium (Hf), Rhenium (Re) with traces of Silicon (Si). Quantification was carried out by analysis of the EDX spectrum on an area of these particles. The results expressed in mass percentage are shown in Table 13.

Table 13: Chemical composition by EDX of the Co(5%)Cu(10%)/ZrO ₂ catalyst

Catalyst Cu(10%) Mn(5%) / ZrO ₂

Observations of MEB images of the reveal the presence of a population of particles with a rounded morphology in the form of agglomerates similar to that of the calcined ZrO ₂ support. These particles are composed mainly of Zirconium (Zr), Copper (Cu), Oxygen (O) and Manganese (Mn), with a minor amount of Hafnium (Hf), Rhenium (Re). Quantification was carried out by analysis of the EDX spectrum on an area of these particles. The results expressed in mass percentage are shown in Table 14.

The MEB observations were also carried out in backscattered electrons and do not show any difference in chemical contrast on the particles.

Table 14: Chemical composition by EDX of the catalyst Cu(10%) Mn(%) /ZrO ₂

Cu(10%) Mn(5%) / γ-Al catalyst ₂ O ₃

Observations of MEB images of the reveal the presence of a population of particles with a rounded morphology of different sizes. This entire population is covered with very small particles with a needle morphology. These particles are mainly composed of Aluminum (Al), Copper (Cu), Oxygen (O) and Manganese (Mn). Quantification was carried out by analysis of the EDX spectrum on an area of these particles. The results expressed in mass percentage are shown in Table 15.

The MEB observations were also carried out in backscattered electrons and do not show any difference in chemical contrast on the particles.

Table 15: Chemical composition by EDX of the catalyst Cu(10%)Mn(5%) / γ-Al ₂ O ₃

Example 9: Composition analysis by ICP-AES

The composition of the catalysts Cu(10%)Mn(%)/ _ZrO2 and Cu(10%)Mn(5%)/γ- _Al2O3 was analyzed by ICP-AES. The results are reported in Tables 16 and ₁₇ respectively.

The samples were mineralized in a solution of 2 mL of nitric acid HNO ₃ + 1 mL of hydrofluoric acid HF for 2 h at 100°C.

Table 16: Chemical composition by ICP-AES of the catalyst Cu(10%) Mn(%) /ZrO ₂

Table 17: Chemical composition by ICP-AES of the catalyst Cu(10%)Mn(5%) / γ-Al ₂ O ₃

Example 10: Surface analysis by XPS

The analyses are carried out with a PHI QUANTES photoemission spectrometer. This device is equipped with a monochromated X-ray source (Kα line of aluminum) as well as a chrome X-ray source for Hard XPS, a charge neutralization system for electrically insulating samples and a hemispherical electron analyzer.

XPS analyses were performed on the Co(5%)Cu(10%)/ZrO ₂ catalyst calcined at 600°C for 2 hours and a sample of the ZrO ₂ support also calcined at 600°C for 2 hours.

XPS spectra are shown in .

A. Quantification of the extreme surface

The quantification of the extreme surface, expressed as a mass percentage, on the two calcined ZrO ₂ and Co(5%)Cu(10%) /ZrO ₂ samples is presented in Table 18 below:

Table 18: Extreme surface chemical composition by XPS of calcined ZrO ₂ and Co(5%)Cu(10%) /ZrO ₂

Both samples have low carbon levels, mainly from air pollution.

The Co(5%)Cu(10%)ZrO ₂ sample consists of Zirconium (Zr), Oxygen (O), Copper (Cu), Cobalt (Co) with traces of Silicon (Si) and Sodium (Na).

The _ZrO2 sample is composed of Zirconium (Zr) and Oxygen (O) with traces of Silicon (Si) and Sodium (Na).

The quantification of the extreme surface, expressed in mass percentage, on the two samples Cu(10%) Mn(5%) /ZrO ₂ and Cu(10%)Mn(5%) / γ-Al ₂ O ₃ is presented in Table 19 below:

Table 19: Chemical composition at the extreme surface by XPS of Cu(10%) Mn(5%)/ZrO ₂ and Cu(10%)Mn(5%)/γ-Al ₂ O ₃

Both samples have low carbon levels, mainly from air pollution.

The Cu(10%) Mn(5%) / ZrO ₂ sample is mainly composed on the extreme surface of Zirconium (Zr), Oxygen (O), Manganese (Mn).

The Cu(10%)Mn(5%) / γ-Al ₂ O ₃ sample is composed mainly of Aluminum (Al) and Oxygen (O) at the extreme surface.

B. Determination of the chemical environments of calcined ZrO ₂ and Co(5%)Cu(10%) /ZrO ₂

The results of the Gaussian deconvolutions of the spectra are presented in Table 20 below:

Table 20: XPS analysis results

C1s spectra:

For all samples, the deconvolution of the C1s carbon spectra presents two components:

- The majority component at 285.0 eV is characteristic of C-C and C-H bonds. These bonds come from atmospheric pollution.

- The component at 288.40 eV is characteristic of C-O and C=O bonds. These bonds are also representative of surface pollution.

O1s spectra:

For all samples, the deconvolution of the oxygen O1s spectra presents two components:

- The majority component at 531.0 eV is characteristic of oxides in general.

- The component at 531.2 eV is characteristic of transition metal oxides.

Si2p spectra:

For all samples, the deconvolution of the Silicon Si2p spectra presents two components:

- The majority component at 103.3 eV is characteristic of silicon oxides SiOx.

- The component at 102.0 eV is characteristic of silicon oxide SiO ₂ .

It should be noted that the characteristic component of Cobalt (II) oxide CoO is located at the same energy as the component corresponding to SiOx.

Na1s spectra:

For all samples, the deconvolution of the Sodium Na1s spectra presents a single component characteristic of atmospheric pollution.

Cu2p3/2 spectrum:

For the sample Co(5wt%)Cu(10wt%)ZrO ₂ , the deconvolution of the spectrum of Copper 2p3/2 presents 2 components:

- The majority component at 934.0 eV is characteristic of Copper (II) Oxide CuO.

The two strong satellite components at 943.5 eV and 963.5 eV are characteristic of Cu ²⁺ ions and therefore of copper (II) oxide CuO.

- The component at 932.6 eV is characteristic of metallic copper or copper (I) oxide Cu ₂ O.

Co2p3/2 spectrum:

For the sample Co(5%)Cu(10%)ZrO ₂ , the deconvolution of the spectrum of Cobalt 2p3/2 presents 2 components:

- The majority component at 781.3 eV is characteristic of Cobalt (III) Oxide Co ₂ O ₃ or Cobalt (II) Hydroxide Co(OH)2

- The component at 779.5 eV is characteristic of metallic Cobalt.

High-resolution XPS spectra of Zirconium 3d5/2

XPS analyses reveal for all samples the majority presence of Zirconium oxide ( _ZrO2 ), with traces of Silicon oxides ( _SiO2 and SiOx) as well as the presence of surface pollution (Carbon and Sodium).

The Co(5%)Cu(10%)/ZrO ₂ sample shows the additional presence of Copper in two oxidized forms: CuO and Cu ₂ O. XPS analyses also reveal the presence of Cobalt for this sample in metallic form but also in the form of Cobalt hydroxide Co(OH) ₂ or Cobalt oxide Co ₂ O ₃ .

C. Determination of the chemical environments of the Cu(10%)Mn(5%) / ZrO ₂ catalysts (spectrum C) and Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D)

The results of Gaussian deconvolutions of the spectra are described below:

Carbon C1s spectra:

The C1s spectra of both samples show the presence of two contributions related to CC/CH bonds and C=O bonds. These bonds are typical of atmospheric pollution.

Oxygen O1s spectra:

The O1s spectrum of Cu(10%)Mn(5%) / ZrO ₂ (spectrum C) presents 3 contributions linked to the Copper (II) oxide CuO, to the Zirconium oxide ZrO ₂ and to the O=C bonds, already identified on the Carbon spectrum.

The O1s spectrum of Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D) presents 4 contributions and highlights the presence of Alumina Al ₂ O ₃ , copper (II) oxide CuO as well as O=C bonds linked to surface pollution.

Copper Cu2p spectra:

The spectra of Copper Cu2p are not interpreted solely by deconvolutions, the position of the different peaks and the overall shape of the spectrum inform us about the degree of oxidation of the element. The overall shape of the Cu2p spectrum of Cu(10%)Mn(5%) / ZrO ₂ (spectrum C) shows the very marked presence of satellite peaks around 943 eV and 963 eV, typical of Cu2+ ions which can notably intervene in the oxidized form CuO.

The deconvolution of the Cu2p3/2 peak also shows the more minor presence of Copper in metallic form and in ionic form Cu+.

The overall Cu2p spectrum shape of Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D) also corresponds to the majority presence of Cu2+ ions as well as Cu+ ions in a smaller proportion.

Manganese Mn2p spectra:

Like Copper Cu2p, the shape of the Manganese Mn2p spectrum tells us about its degree of oxidation.

Cu(10%)Mn(5%) / ZrO ₂ (spectrum C)

The overall shape of the Mn2p spectrum of Cu(10%)Mn(5%) / ZrO ₂ shows the presence of a satellite peak around 648 eV, typical of Mn2+ ions. The deconvolution of the Mn2p3/2 peak confirms that this oxidation state (II) is mainly represented on the surface of the sample with the presence of a smaller number of Mn3+ ions and Mn4+ ions.

Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D)

The overall Mn2p spectrum shape of Cu(10%)Mn(5%) / γ-Al ₂ O ₃ does not appear to have a satellite peak related to Mn2+ ions.

The deconvolution of the Mn2p3/2 peak confirms that for this sample, the ions predominantly present on the surface are the Mn3+ ions. The Mn2+ and Mn4+ ions are also identified in smaller proportions.

Zirconium Zr3d spectrum:

The Zr3d spectrum of Cu(10%)Mn(5%) / ZrO ₂ (spectrum C) is composed of a spin-orbit doublet whose contributions are all linked to Zirconium Oxide ZrO ₂

Aluminum Al2p spectrum:

The Al2p Aluminum spectrum of Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D) shows a single component related to alumina Al ₂ O ₃ . The shoulder observed around 77 eV corresponds to the 3p peak of Copper.

Silicon Si2p and Sodium Na1s spectrum:

The Silicon Si2p spectrum of Cu(10%)Mn(5%) / ZrO ₂ (spectrum C) shows the presence of Silicon oxide SiO2.

The Sodium Na1s Cu(10%)Mn(5%) / ZrO ₂ spectrum (spectrum C) presents a unique component characteristic of atmospheric pollution.

Conclusion

Cu(10%)Mn(5%) / ZrO ₂ (spectrum C)

XPS analyses of Cu(10%)Mn(5%) / ZrO ₂ show the majority presence of Zirconium oxide ZrO ₂ on the surface. The presence of Manganese in a smaller proportion is also identified. Manganese appears in different ionic forms Mn2+, Mn3+ and Mn4+. The majority form Mn2+ noted could be compatible with the presence of MnO oxide. The more minor presence of Mn3+ ions could be compatible with the CuMn2O4 compound identified in XRD. The presence of Copper is also identified in the form of Cu2+ ions. This ionic form is compatible with the Copper (II) oxide CuO as well as the CuMn ₂ O ₄ compound

Cu(10%)Mn(5%) / γ-Al ₂ O ₃ (spectrum D)

XPS analyses of Cu(10%)Mn(5%) / γ-Al ₂ O ₃ show the majority presence of Aluminum oxide Al ₂ O ₃ on the surface. The presence of Manganese in a smaller proportion is also identified. Manganese appears in different ionic forms Mn2+, Mn3+ and Mn4+. The majority form Mn3+ noted could be compatible with the CuMn ₂ O ₄ compound identified by XRD. The presence of Copper is also identified in the form of Cu2+ ions. This ionic form is compatible with the Copper (II) oxide CuO as well as the CuMn ₂ O ₄ and CuAl ₂ O ₄ compounds identified by XRD.

Example 11 - Continuous flow hydrogenation procedure

A solution of oxamide between 0.05 and 0.5 M in THF is pumped into the reactor at a flow rate between 0.3 and 3 mL/min. Then, the system pressure is set between 30 and 100 bars using a discharger, then the reactor is heated between 150 and 220 °C. The reactor is composed of a stainless steel tube in which the catalyst used for the reaction is located (between 150 and 700 mg). Finally, hydrogen - produced in situ in the equipment or introduced from outside via a valve - is injected into the system at the desired flow rate between 20 and 100 mLN/min. Optionally, the catalyst is previously brought into contact with the hydrogen flow before introducing the reagents. Once the system is stabilized, the product is collected at the reactor outlet in vials before being analyzed by GC-MS.

Example 12 – Procedure for the degradation of ethylene glycol by reduction under hydrogen in the presence of the CuCo / ZrO2 catalyst

In a 450 mL Parr autoclave equipped with a magnetic stirrer, a heterogeneous catalyst based on copper (4 mmol Cu) and cobalt, ethylene glycol (10 mmol), a base, potassium tert-butoxide (KOtBu) and as solvent tetrahydrofuran (THF) (75 mL) were introduced. The reactor was sealed, and the reaction mixture was purged three times with nitrogen (5 bar), and twice with hydrogen (5 bar).

The autoclave was then pressurized with 60 bars of hydrogen. The reaction medium was then brought under stirring from 180 to 200°C for 15 hours.

Once the reaction was complete, the autoclave was brought back to room temperature before being depressurized and purged three times with nitrogen (5 bars).

The final mixture obtained was diluted and then an internal standard was added (mesitylene), to calculate the conversion of ethylene glycol using GC-MS.

The balance of the degradation reaction of ethylene glycol by hydrogenation in the presence of the CuCo/ZrO2 catalyst is written as follows

Example 13 – Tests carried out with the Cu-Co / ZrO ₂ catalyst.

Table 21 reports the conditions of the ethylene glycol degradation tests by hydrogenation in the presence of a CoCu/ _ZrO2 catalyst prepared according to Example 5. The conversion of ethylene glycol is calculated using GC-MS, mesitylene is used as an internal standard.

Table 21: Conditions of the ethylene glycol hydrogenation tests in the presence of a CoCu/ _ZrO2 catalyst and the results obtained.

Claims (11)

Use of a bimetallic supported catalyst, comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, in the implementation of a process for preparing ethylene glycol from an oxamide or oxamate compound by a hydrogenation reaction of said oxamide or oxamate compound with hydrogen (H ₂ ) to obtain ethylene glycol. Use according to claim 1, wherein said support is an oxide, in particular zirconium dioxide (ZrO ₂ ) or alumina (γ-Al ₂ O ₃ ). Bimetallic supported catalyst comprising copper and a metal M selected from Mn, Co, Ni and Fe, on a zirconium dioxide support, of formula Cu-M/ZrO ₂ ,
wherein said catalyst has a surface area, analyzed by BET, of 1 to 250 m²/g, preferably of 1 to 50 m²/g, preferentially of 1 to 10 m²/g, in particular of approximately 5 m²/g
and wherein said catalyst comprises a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystal system, in particular said crystalline phase represents from 50 to 90% by total weight of the catalyst, preferably said crystalline phase being baddeleyite and preferably comprising a crystallite size of 15 to 100 nm. Process for the preparation of ethylene glycol comprising:

• a step of hydrogenation by hydrogen of an oxalate or oxamate compound, into ethylene glycol, in the presence of a bimetallic supported catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe.

A process for preparing ethylene glycol according to claim 4, wherein:

• the hydrogenation step includes
  • contacting:

• said oxamide or oxamate compound,
• dihydrogen,
• said supported bimetallic catalyst comprising copper and a metal M selected from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents Mn, Co, Ni or Fe,
• possibly from a base
• possibly a solvent,

to obtain a reaction medium possibly put under pressure,

• possibly heating of said reaction medium,

to obtain ethylene glycol. Process for the preparation of a Cu-M/Support catalyst, comprising:

• a step A of impregnation of a copper salt and a salt of the metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a support in powder form, with a mass of the solution / mass of support ratio of from 0.6 to 1.0;

to obtain the Cu-M catalyst / Support in the form of a homogeneous mixture,

• a step B of drying said homogeneous material, at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M catalyst / Support in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination in air of said dry homogeneous mixture at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-M/Support catalyst.

Process according to claim 6 for the preparation of a Cu-M/ZrO catalyst.₂according to claim 3 comprising:

• a step A of impregnation of a copper salt and a salt of the metal M, M being chosen from Mn, Co, Ni and Fe, dissolved in an aqueous solution, free of additive and surfactant, in a volume of water of 5 to 10 mL, on a support in powder form, with a mass ratio of the solution / mass of support of from 0.6 to 1.0

to obtain the Cu-M/ZrO catalyst₂in the form of a homogeneous mixture,
said support
having a surface area of 1 to 250 m²/g, preferably 1 to 50 m²/g, preferentially 1 to 10 m²/g, in particular approximately 5 m²/g,
and comprising a crystalline phase, analyzed by X-ray diffraction, crystallized in a monoclinic crystalline system,

• a step B of drying said homogeneous mixture, preferably at a temperature of 60 to 100°C, for a period of 10 to 24 hours, to obtain the Cu-M / ZrO ₂ catalyst in the form of a dry homogeneous mixture,
• an activation step C, comprising calcination of said dry homogeneous mixture, preferably at a temperature of 200 to 1000°C, for a period of 1 to 15 hours, to obtain said Cu-M / ZrO ₂ catalyst.

Bimetallic supported catalyst comprising copper and a metal M chosen from Mn, Co, Ni and Fe, on a support, of formula Cu-M / Support, capable of being obtained by the process for preparing a catalyst according to one of claims 6 or 7. Process for the preparation of ethylene glycol according to one of claims 4 or 5, in which said catalyst is according to one of claims 3 or 8. Use of a catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, for the hydrogenolysis of ethylene glycol. Use of a catalyst comprising copper and a metal M chosen from manganese, cobalt, nickel and iron, on a support, of formula Cu-M / Support, in which M represents respectively Mn, Co, Ni or Fe, to depolymerize biomass.