JPS62201646A - Production or composite oxide catalyst - Google Patents

Abstract

PURPOSE:To obtain a catalyst having high selectivity by using heat-treated composite oxide shown in Sb-X-Si-O as one part of feed source of antimony for a composite oxide catalyst. CONSTITUTION:In case of using a composite oxide catalyst contg. Sb, Mo, V and/or Nb in the vapor phase catalytic oxidizing reaction, a composite oxide which is shown in Sb-X-Si-O (wherein X shows Fe, CO, Ni and Bi) and heated at 600-900 deg.C is used as one part of a feed source of antimony. In such a way, in case of introducing some of X componential elements in a form of antimonate in an Sb-Mo-V and/or Nb-X-Y-O catalyst, Si is compounded into this antimonate and thereby a composite oxide catalyst excellent in selectivity is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background of the Invention] 1. The present invention relates to a method for producing a composite oxide catalyst containing at least Sb, MO, V and/or Nb. More specifically, the present invention provides specific component elements, namely 3b
The present invention relates to a method for producing a composite oxide catalyst having a main feature in the mode of introduction. A composite oxide catalyst containing at least Sb, MO, (1) and (or) Nb is well known for use in gas phase catalytic oxidation reactions. Specifically, the gas phase catalytic oxidation reaction in this case includes a reaction in which an olefin is oxidized to an unsaturated aldehyde or an unsaturated carboxylic acid, and an olefin is oxidized in the presence of ammonia (ammo-oxidation) to form an unsaturated nitrile. reaction, oxidative dehydrogenation of a saturated aldehyde or saturated carboxylic acid to form an unsaturated carboxylic acid, and others.

As is clear from these examples, "vapor phase catalytic oxidation" includes "ammo oxidation" and "oxidative dehydrogenation" in addition to simple oxidation (the present invention also applies to this definition).
), they share the characteristic that they are carried out in the presence of molecular oxygen (air and/or oxygen gas).

The above-mentioned gas phase catalytic oxidation reaction carried out in the presence of molecular oxygen involves an undesirable sequential reaction in which a part of the target product is further oxidized and converted into a product with low added value. There are many.

It has long been well known that in order to suppress this sequential reaction as much as possible, one of the factors is how to improve the effectiveness coefficient of the catalyst during the reaction.

Improving the effective coefficient of the catalyst corresponds to minimizing the diffusion resistance of the reactants during the reaction.

It is well known that the catalyst shape and pore distribution are the most dominant factors regarding the effectiveness coefficient of a catalyst.
The relationship between the catalyst shape and the effective coefficient is discussed in ``Chemical Engineering Society of Japan, published in 1966'', and ``Chemical Engineering rVJ <W
! The relationship between the pore distribution and the effective coefficient is discussed on pages 32 to 37 (edited by Fumi Tashige and Hiraichi Tsukahata, published by Tokyo Kagaku Dojinsha, 1963).

By the way, as mentioned above, a composite oxide catalyst containing at least Sb, MO, V63, and/or Nb is well known, and a specific example thereof is disclosed in JP-A-47-
No. 18823, No. 49-43922 and No. 52-2
Publication No. 3589 can be mentioned. According to these publications, there is no special description regarding the pore distribution related to the above-mentioned effective coefficient when preparing the catalyst, but Sb and N
It has been shown to be advantageous to use nickel antimonate in the form of S
A method of manufacturing by combining a b source and an N1 source and 'l& thermal treatment is disclosed. These catalysts can use silica as a carrier.

[Summary of the invention]

l Once the present inventors have added silica before high-temperature heat treatment when producing the above-mentioned Sb-N i -0 composite, Sb-N i -Si-0 having a more macroscopic pore diameter can be produced. It is possible to obtain a composite oxide of We discovered that B1 exists.

The present invention debunks these discoveries.

Therefore, the method for producing a composite oxide catalyst according to the present invention involves producing a composite oxide catalyst containing at least Sb, MO, (1) and (or) Nb by a process consisting of combining and heating sources of each required element. , Sb-X-3+ -0 (where X
It is characterized by using a composite oxide having a history of being heated at 600 to 900° C., which is represented by at least one type b selected from the group consisting of G, tFei, Go, N1, and B1.

Effect Sb-Mo-V and tfLt)Nb-X-Y-0(
When X is an element that coexists in the form of an antimonate, and Y is an element that coexists with the present catalyst in the form of an antimonate, according to the present invention, 3i is added to the antimonate. By combining with a salt, a composite oxide catalyst with improved selectivity can be obtained.

It is well known that silica is used as a support for complex oxide catalysts, but its presence during antimonate formation makes it possible to reduce the pores inherent in the original antimonate and silica, respectively. It is understood that it was unexpected that a composite oxide with macroscopic pores could be produced and the selectivity of the produced catalyst was significantly improved (see Comparative Example below). Also Fe1CO1N
It should also be said that it was unexpected that this technique could be applied to i and 3i and similarly highly selective catalysts could be obtained.

In addition, in accordance with the present invention, the formation of antimonate in the above refers to heat-treating (600 to 900°C) the combination of each element source compound. This does not necessarily imply the formation of antimonate as a chemical (nor is there any practical benefit in confirming its formation).

[Detailed description of the invention]

The catalyst according to the present invention comprises Sb, Mo, ■ and (or >
It belongs to the category of composite oxide catalysts containing at least Nb. This catalyst system can be schematically represented by the formula below.

Sb-Mo-V and/or Nb-X-Y- Here, X is an element coexisting in the form of antimonate, specifically Fe, Go, Ni, and (3i).

Y is an element that coexists in this catalyst system, specifically,
For example, W, Cu, etc.

This type of composite oxide catalyst is usually used by adding and molding silica, alumina, refractory oxides, etc., or by supporting them, but these components and catalyst components are clearly distinguished. Since this may be difficult, for example, the above 3i of silica may be regarded as a component of Y.

As mentioned above, such a composite oxide catalyst is well known, and in the present invention, the composition and production method may be any suitable for the purpose, except for improvements specific to the present invention. As for the production method, it is basically desirable to combine the catalyst component element sources all at once or in stages, carry out support or shaping at an appropriate time in the process of combination, and finally heat-treat. Regarding the shape of the catalyst, it is natural that it is desirable to have a small Ar15 radius for the purpose of increasing the effective coefficient.

Antimony Source The antimony source used according to the present invention to also introduce Fe, Go, Ni and 8 into the basic catalyst system is S
b-X-Si -0 (X is 1"e, C01N
at least one selected from the group consisting of i and B1)
It is a composite oxide that has a history of being heated at 600 to 900°C.

Since this composite oxide is a composite oxide, it can be prepared in ml by the method described above regarding the basic catalyst system.
can be manufactured. Specifically, in terms of raw materials, metal antimony, antimony oxide, etc. are used as Sb supply sources, Fe
As the 1CO1N+, Bi supply source, these nitrate M salts, chlorides, etc. are used, and as the Si supply source, colloidal silica, granular silica, etc. are used.In terms of operation, for example, antimony trioxide powder and silica are mixed with iron nitrate ( Or Co.

Nitrate of N1 or 3i) is added to an aqueous solution, evaporated to dryness with stirring, and the resulting solid is calcined at 600 to 900°C, preferably 650 to 850°C, in the presence of air.

If the solid after calcination cannot be obtained as a powder, it is appropriately pulverized and used as at least a part of the Sb source for the catalyst of the present invention.

The atomic ratio of this composite oxide, that is, W-Z of Sb -x -s-o is as follows:
Preferably, it is ly Z .

W: 1-401 preferably 1-20 x: 1-20, preferably 1-10 y: 1-10. Preferably (41-5 2: Number determined by the degree of oxidation of each component.

wood! At least a part of the Sb source is the above-mentioned Sb-x-Si-
The catalyst according to the present invention can be manufactured according to the method for manufacturing a composite oxide catalyst as described above, except that it is a composite oxide. It is preferred that at least 25% or more, preferably 50% to 100%, of the Sb in the finished catalyst be supplied by the above composite oxide.

To give a specific example of catalyst production, the Sb-X-Si-0 composite oxide powder obtained as described above is mixed with a multiple acid of MO, V or Nb (for example, molybdic acid or phosphomolybdic acid) or salts (e.g. ammonium salts)
, hydroxides or salts of these metals, and optionally added components (the aforementioned Y component), such as copper compounds and tungsten compounds, are wet mixed, concentrated, dried, and then pulverized. The obtained powder is shaped (tabletted, extruded, etc.) into an appropriate shape, such as small granules, trabecular shapes, and ring shapes, as it is or together with suitable carriers and excipients such as silica, graphite, and Avicel. (depending on the method), then 1 at a temperature of about 300 to 500℃.
The mixture is heated for about 10 hours to obtain a composite oxide catalyst. The heating atmosphere in this case is preferably non-reducing, preferably in the coexistence of molecular oxygen.

The catalyst of the present invention thus obtained has a composition schematically represented by the following formula.

(Sb) a(Mo)b (V and/or) N b
) c

a: 1-100, preferably 10-100 b: 1-10
0, preferably 1-50 C: 0.1-50, preferably 1-20d: 1-100
, preferably 10-100e: 0.1-50, preferably 1-20f: 1-100, preferably 10-1o.

g = number determined by the degree of oxidation of each component element The catalyst of the present invention obtained in this manner has an average pore diameter of 200.8 or more, and was obtained without introducing Sb by the method of the present invention. The average pore diameter of conventional catalysts is 400 to 100OA.
It contrasts sharply with the fact that Note that here [average thin
The pore diameter J is measured by a porosimeter using a mercury intrusion method, and indicates the maximum position of the differential curve.

Use of the Catalyst The catalyst according to the invention is used in gas phase catalytic oxidation reactions to give the target compound with high selectivity. As mentioned above, the gas phase catalytic oxidation reaction in this case has a broad meaning including ammoxidation and oxidative dehydrogenation.

One of the preferred uses of the catalyst according to the invention is in the oxidation of unsaturated aldehydes IC, such as acrolein or methacrolein, to produce the corresponding unsaturated carboxylic acids, ie acrylic acid or methacrylic acid. That is, the process of producing acrylic acid or methacrylic acid by vapor phase catalytic oxidation of an olefin, such as propylene or isobutyne, is carried out by dividing it into two steps: production of an unsaturated aldehyde by oxidation of the olefin, and production of an unsaturated carboxylic acid by the oxidation. The most typical use target of the catalyst of the present invention is the latter stage reaction in which the catalyst of the present invention is used. In this case, the catalyst used in the gas phase catalytic oxidation reaction in the first step is Mo.
-3i composite oxide catalysts are well known and widely used industrially. It is also well known that these Mo-Si-based composite oxide catalysts are extremely useful for ammoxidation and oxidative dehydrogenation reactions.

136 g of nickel nitrate is dissolved in 90 d of warm water, and 509 g of silica (Carplex #67) and 159 g of antimony trioxide are gradually added thereto with stirring. This slurry liquid is concentrated by heating and dried at 90°C. Then,
This is fired in a Matsufuru furnace at 800°C for 3 hours. The produced solid is crushed and passed through a 60 mesh sieve (Sb-N
i-3i-0 powder).

Heating 540 d of pure water to about 80°C, 8.1 g of ammonium paratungstate and 63 g of ammonium paramolybdate were added.
9 g of ammonium metavanadate, 8.4 g of ammonium metavanadate, and 7.8 g of cuprous chloride were sequentially added and dissolved with stirring. Next, the above Sb-Ni-Si-0 powder is gradually added to this solution while stirring, and the mixture is thoroughly mixed. This slurry is heated to 80-100°C to concentrate and dry. This dried product is crushed and passed through a 24-mesh sieve. 1.5 for this
% by weight of graphite is added and mixed, and the mixture is molded into a cylindrical shape of 5φ×4 h I/l using a small tablet molding machine. This was fired in a Matsufuru furnace at 400°C for 5 hours to obtain a catalyst.

The composition of the catalyst obtained here is as follows in atomic ratio.

Sb:Ni:Si:MO:V:W:Cu=100:
43:80:35Near:3:3゛This catalyst (50Id) was packed into a stainless steel night jacketed reaction tube having an inner diameter of 20III/I11 and a length of 500Ill/m to carry out a catalytic oxidation reaction of acrolein. The raw material gas is 4% acrolein, 46% steam and 50% air, and O
It was made to flow through this reaction tube at a "CC standard speed of 870 h".

In a night bath ff of 1250° C., the acrolein conversion rate was 98.4%, the acrylic acid rancidity rate was 94.7%, and the selectivity to acrylic acid was 96.2%.

Comparative Example 1 136 g of nickel nitrate is dissolved in 90 d of warm water, and 159 g of antimony trioxide is gradually added thereto with stirring. This slurry liquid is concentrated by heating and dried at 90°C. Next, this is fired in a Matsufuru furnace at 800° C. for 3 hours. The produced solid is pulverized and passed through a 60 mesh sieve (Sb-Ni-〇 powder).

Pure water 540d! was heated to about 80°C, and 8.1 g of ammonium paratungstate and 63 g of ammonium baramolybdate were added.
9 g, ammonium metavanadate, 8.4 g, and cuprous chloride, 2.8 g, are sequentially added and dissolved with stirring. Next, the above Sb-Ni-0 powder is added to this solution and thoroughly stirred and mixed. Next, silica (Carplex #67)
Add 509 and mix thoroughly. Below, Example 1Ji
A catalyst was prepared in the same manner as No. 31, and the reaction evaluation was conducted in the same manner.

At a night bath temperature of 270°C, the acrolein conversion rate was 9.
The yield of acrylic acid was 91.2%, and the selectivity to acrylic acid was 93.2%.

Example 2 The same catalyst production and reaction evaluation as in Example 1 were carried out using 189 g of ferric nitrate instead of 136 g of nickel nitrate in Example 1.

The composition of the obtained catalyst is as follows.

Sb:Fe:Si:Mo:V:W:Cu-100:4
3:80:35 Near: 3:3 Naita single bath at 260°C, acrolene conversion rate 99.9%, acrylic acid yield 9
The selectivity to acrylic acid was 94.3%.

Sb-Go-Si
-0 powder was produced.

Next, 540 d of pure water was heated to about 80°C, and 63.9 g of ammonium baramolybdate and 8.9 g of ammonium metavanadate were added.
4g of niobium hydroxide (NbO(0)-1>3>4.6g) and 5.6g of cuprous chloride are sequentially added with stirring to dissolve and mix.The above Sb-Go-Si-0 powder is added to this solution. was gradually added and stirred to mix thoroughly.A catalyst having the following composition was obtained in the same manner as in Example 1.

Sb:Co:Si:Mo:V:Nb:Cu-100:
A catalytic oxidation reaction of acrolein was carried out in the same manner as in Example 1 using the 43:80:35 near:3 catalyst.

At a night bath temperature of 260°C, the acrolein conversion rate was 9.
The yield of acrylic acid was 95.2%, and the selectivity to acrylic acid was 95.3%.

Example 4 133 g of metallic antimony is added little by little to 700 d of nitric acid with stirring and oxidized. After no nitric acid gas is generated, 277 g of bismuth nitrate is added and stirred thoroughly. Next, silica sol (Nortex N containing 20% Si02) 1255F is added, heated and concentrated while stirring, and dried. After firing this in air at 800°C for 3 hours, it is pulverized (Sb-B i -Si
-0 powder). Next, 540 g of pure water is heated to about 80° C., and 63.9 g of ammonium baramolybdate, 8.49 g of ammonium metavanadate, 4.6 g of niobium hydroxide, and 21.2 g of copper sulfate are sequentially dissolved and mixed with stirring. . The above Sb-s+ to 5i-0 powders are gradually added to this liquid and mixed thoroughly. Thereafter, in the same manner as in Example 1, a catalyst having the following composition was obtained.

Sb:Bi:Si:Mo:V:Nb:Cu-100
:43:40:35 Near:3:9 Using this catalyst, a catalytic oxidation reaction of acrolein was carried out in the same manner as in Example 1.

At a night bath temperature of 260°C, the acrolein conversion rate was 99.
2%, acrylic acid yield 92.6%, and selectivity to acrylic acid 93.3%.

Example 5 Sb-N 1-Go-Si-O powder was produced in the same manner as in Example 1, except that 68 g of nickel nitrate and 68 g of cobalt nitrate were used instead of 136 g of nickel nitrate in Example 1. Similar catalyst production and reaction evaluation were carried out below.

The composition of the obtained catalyst is as follows.

Sb:Co:Ni:Si:Mo:V:W:Cu-1
00:21.5:21.5:80:35 Near: 3:3 Night game bath i! At 260°C, the acrolein conversion rate was 99.9%, the acrylic acid yield was 94.9%, and the selectivity to acrylic acid was 95.0%.

Claims (1)

[Claims] In producing a composite oxide catalyst containing at least Sb, Mo, V, and (or) Nb by a process consisting of combining and heating sources of each required element, at least part of the source of Sb, A composite using a composite oxide represented by Sb-X-Si-O (where X is at least one selected from the group consisting of Fe, Co, Ni, and Bi) and has a history of being heated at 600 to 900°C. Method for producing oxide catalyst.