CN104447204B - A kind of method for preparing diol - Google Patents

Abstract

The invention relates to a method for epoxidizing olefins to produce epoxy compounds and then hydrolyzing them to prepare diols under the action of a certain amount of oxidant. The method adopts TS-1 molecular sieve loaded with rare earth metal oxide as a catalyst. The specific process is: add olefins and catalysts into the reaction vessel, and react in a certain amount of solvent at room temperature to 150°C. The conversion rate of olefins is 40%-85% and the selectivity of diols is 75%-90% as measured by chromatography. . In the method for preparing diol involved in the present invention, the preparation of the catalyst is simple, the stability is high, the reaction conditions are relatively mild, and the conversion rate of olefin and the selectivity of diol are both high.

Description

A kind of method for preparing diol

technical field

The invention relates to a method for preparing diols, in particular to a process in which olefins are epoxidized to generate epoxy compounds and then hydrolyzed to prepare diols.

Background technique

Glycols are an important class of chemical products with important application value. 1,2-Propanediol can be used as a raw material for unsaturated polyester resins, as well as plasticizers, surfactants, emulsifiers and demulsifiers, as well as antifungal agents, fruit ripening agents, preservatives, antifreeze agent and tobacco humectant. Ethylene glycol can be used to produce polyester resins, including fibers, films and engineering plastics, and can also be directly used as coolants and antifreeze agents. It is also used to produce alkyd resins, plasticizers, paints, adhesives, surfactants, explosives And capacitor electrolyte and other products are indispensable substances.

Epoxides are intermediates of various industrial products, and are also important raw materials in fine chemical fields such as spices and pharmaceuticals. With the in-depth research on molecular sieves, titanium silicalite (TS-1, Ti-β, etc.) as an efficient selective oxidation catalyst material can complete the epoxidation of many olefins in one step, and the reaction conditions are mild.

Oxidants are safe and easy to obtain, and there is basically no environmental pollution problem. Among them, the epoxidation of propylene has been industrialized, which provides a development path for the production of diols.

MasazumiTamura et al. (Chem.Eur.J.2011,17,1142811431) report that cerium dioxide can be an effective catalyst to catalyze the hydrolysis of nitriles to prepare amides; our research work (J.Am.Chem.Soc.2013,135,15061515 ) proves that ceria has a certain acidity and can hydrolyze and break ether oxygen bonds.

Although there have been many reports on olefin epoxidation and epoxide hydrolysis, there are few studies on the one-step preparation of diols by olefin epoxidation and hydrolysis. Therefore, the development of bifunctional catalysts to achieve one-step preparation of diols has attracted extensive attention of researchers.

Contents of the invention

The significance of the present invention is to overcome the shortcomings existing in the current diol preparation process, such as: the preparation process is complicated, it needs two steps to complete, and the reaction selectivity is poor. The TS-1 catalyst supported by the rare earth metal oxide used in the process has epoxidation and hydrolysis properties, is simple to prepare, has high stability, and has high conversion rate and selectivity.

A diol preparation scheme designed by the present invention is characterized in that: TS-1 molecular sieve loaded with rare earth metal oxides is used as a catalyst, olefin and catalyst are added to the reaction vessel, and the product diol is obtained under the condition of the presence of an oxidizing agent in a solvent . In the TS-1 molecular sieve loaded with rare earth metal oxides, the rare earth metal oxides are: lanthanum trioxide, cerium trioxide, cerium dioxide, europium trioxide, and ytterbium trioxide; preferred rare earth metal oxides The compound is one or two kinds of ceria and europium trioxide; the loading amount of the metal oxide in the catalyst is: 1wt%-20wt%; the preferred loading amount is: 5wt%-10wt%.

The preparation process of the TS-1 molecular sieve loaded with rare earth metal oxides is as follows: TS-1 is soaked in a soluble salt solution containing rare earth metals, left standing for 3h-48h, dried and calcined in an air atmosphere. The TS-1 can be prepared by one of hydrothermal synthesis method, microwave radiation heating method and isomorphic substitution method, wherein Ti:Si (wt:wt)=0.5%-2.5%.

The added olefins are: one or more of chloropropene, butene, pentene, hexene, cyclohexene, and styrene; preferred olefins are: chloropropene, cyclohexene or styrene One or more of them; the oxidizing agent is: one or more of hydrogen peroxide, tert-butyl hydroperoxide, urea peroxide, and cumene hydroperoxide; the preferred oxidizing agent is: hydrogen peroxide with one or both of urea peroxide;

The molar ratio of the added olefin to water is 10-1:1, and the concentration of the added olefin in the solvent is 0.1-1molL ^-1 ; the catalyst consumption is 0.05g (g substrate) ^-1 -0.5g (g substrate) ^-1 ; the molar ratio of the oxidizing agent to the alkene is greater than or equal to 1. The reaction temperature is from room temperature to 150°C, and the reaction time is 1h-72h. The preferred reaction temperature is 50°C-100°C, and the reaction time is 3h-24h; the solvent is: one of acetone, acetonitrile, and methanol Mixture of one or more kinds with water, or pure water, the volume content of water in the mixture is 10-50%.

The catalyst can be separated by filtration or centrifugation, and the catalyst can be reused after roasting.

Compared with the published anhydrous formaldehyde preparation process, the present invention has the following advantages: 1. The reaction conditions are relatively mild; 2. The conversion rate of olefins and the selectivity of diols are high; 3. The reaction uses rare earth oxides The supported TS-1 is used as a catalyst, the material is easy to obtain, the preparation is simple, and the stability is high.

detailed description

In order to further describe the present invention in detail, several specific implementation examples are given below, but the present invention is not limited to these examples.

Example 1

Slowly add 7.3g ethyl orthosilicate dropwise to the solution of 12.8mL tetrapropylammonium hydroxide (20% aqueous solution) and 20mL water, stir vigorously at room temperature until clear, and dissolve 0.13g tetrabutyl titanate in After 6mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, and place it in an oven at 180°C for 6 hours; after the crystallization is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and roasted at 550°C for 8 hours to obtain TS-1. Get its Ti:Si=1%. It was immersed in cerium nitrate solution to prepare ceria-supported TS-1 with a ceria loading of 5 wt%. Add 2 mmol of allyl chloride and 0.02 g of catalyst into the reaction flask, add 2 mL of acetone and 1 mL of water, and react at 60 ° C for 20 h. The conversion rate of allyl chloride is 78% and the selectivity of diol is 90% as measured by chromatography.

Example 2

Slowly add 9.0g ethyl orthosilicate dropwise into a solution of 16.0mL tetrapropylammonium hydroxide (20% aqueous solution) and 30mL water, stir vigorously at room temperature until clear, and dissolve 0.28g tetrabutyl titanate in After 10mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, heat it with microwave assistance to 150°C, and keep it for 3 hours; after the heating is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and calcined at 500°C for 4 hours to obtain TS-1. Its Ti:Si=1.8% was measured. It was immersed in europium nitrate solution, evaporated to dryness at 100°C, and calcined at 500°C for 2 hours to prepare TS-1 loaded with europium trioxide, and the loading amount of europium trioxide was 10wt%. Add 2mmol cyclohexene and 0.02g catalyst into the reaction flask, add 2mL acetonitrile and 1mL water, and react at 80°C for 24h. The conversion rate of cyclohexene is 60% and the selectivity of diol is 85% as measured by chromatography.

Example 3

Slowly add 7.3g ethyl orthosilicate dropwise to the solution of 12.8mL tetrapropylammonium hydroxide (20% aqueous solution) and 20mL water, stir vigorously at room temperature until clear, and dissolve 0.13g tetrabutyl titanate in After 6mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, and place it in an oven at 180°C for 6 hours; after the crystallization is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and roasted at 550°C for 8 hours to obtain TS-1. Get its Ti:Si=1%. It was immersed in a lanthanum nitrate solution to prepare TS-1 loaded with dilanthanum dioxide, and the loading amount was 5wt%. Add 2mmol chloropropene and 0.02g catalyst into the reaction flask, add 2mL acetone and 1mL water, and react at 60°C for 20h. Chromatography shows that the conversion rate of chloropropene is 75%, and the selectivity of diol is 90%.

Example 4

Slowly add 9.0g ethyl orthosilicate dropwise into a solution of 16.0mL tetrapropylammonium hydroxide (20% aqueous solution) and 30mL water, stir vigorously at room temperature until clear, and dissolve 0.28g tetrabutyl titanate in After 10mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, heat it with microwave assistance to 150°C, and keep it for 3 hours; after the heating is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and calcined at 500°C for 4 hours to obtain TS-1. Its Ti:Si=1.8% was measured. It was immersed in europium nitrate solution, evaporated to dryness at 100°C, and calcined at 500°C for 2 hours to prepare TS-1 loaded with europium trioxide, and the loading amount of europium trioxide was 10wt%. Add 2mmol styrene ene and 0.02g catalyst into the reaction flask, add 2mL acetone and 1mL water, and react at 80°C for 48h. The conversion rate of cyclohexene is 70% and the selectivity of diol is 89% as measured by chromatography.

Example 5

Slowly add 10.6g of ethyl orthosilicate dropwise into a solution of 12.8mL of tetrapropylammonium hydroxide (20% aqueous solution) and 20mL of water, stir vigorously at room temperature until clear, and dissolve 0.42g of tetrabutyl titanate in After 8mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, and place it in an oven at 185°C for 8 hours; after the crystallization is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and roasted at 500°C for 5 hours to obtain TS-1. Get its Ti:Si=2.1%. It was immersed in cerium nitrate solution to prepare TS-1 supported by ceria, and the ceria loading was 2 wt%. Add 2mmol of allyl chloride and 0.02g of catalyst into the reaction flask, add 2mL of acetone and 1mL of water, and react at 80°C for 24h. The conversion rate of allyl chloride is 85% and the selectivity of diol is 88% as measured by chromatography.

Example 6

Slowly add 10.6g of ethyl orthosilicate dropwise into a solution of 12.8mL of tetrapropylammonium hydroxide (20% aqueous solution) and 20mL of water, stir vigorously at room temperature until clear, and dissolve 0.42g of tetrabutyl titanate in After 8mL of isopropanol, under the protection of nitrogen, it was slowly added dropwise to the aforementioned sol, and stirred for about 1 hour. Add the above mixture into the synthesis kettle, seal it, and place it in an oven at 185°C for 8 hours; after the crystallization is completed, it is quenched, washed with deionized water repeatedly until neutral, dried, and roasted at 500°C for 5 hours to obtain TS-1. Get its Ti:Si=2.1%. It was immersed in cerium nitrate solution to prepare TS-1 supported by ceria, and the ceria loading was 8 wt%. Add 2 mmol of allyl chloride and 0.02 g of catalyst into the reaction flask, add 3 mL of water, and react at 80 ° C for 24 hours. The conversion rate of allyl chloride is 80% and the selectivity of diol is 78% as measured by chromatography.

Claims (9)

1. prepare a method for glycol, it is characterized in that:

Adopt the TS-1 molecular sieve of supported rare earth metal oxide as catalyzer, in reaction vessel, add alkene and catalyzer, in a solvent, under oxygenant existence condition, obtain product glycol;

Rare-earth oxide is: lanthanum sesquioxide, cerous oxide, cerium dioxide, europiumsesquioxide, yttria; The charge capacity of metal oxide in catalyzer is: 1wt% ~ 20wt%;

The described alkene added is: one or two or more kinds in propenyl chloride, butylene, amylene, hexene, tetrahydrobenzene, vinylbenzene;

Described oxygenant is: one or two or more kinds in hydrogen peroxide, tertbutyl peroxide, carbamide peroxide, hydrogen phosphide cumene;

Described temperature of reaction is room temperature to 150 DEG C, and the reaction times is 1h ~ 72h.

2. in accordance with the method for claim 1, it is characterized in that:

In the TS-1 molecular sieve of described supported rare earth metal oxide, preferably rare-earth oxide be cerium dioxide, europiumsesquioxide one or both; The better charge capacity of metal oxide in catalyzer is: 5wt% ~ 10wt%.

3. in accordance with the method for claim 1, it is characterized in that:

The preparation process of the TS-1 molecular sieve of described supported rare earth metal oxide is as follows: be immersed in by TS-1 in the soluble salt solutions containing rare earth metal, leaves standstill 3h ~ 48h, roasting in drying, air atmosphere.

4., according to the method described in claim 1,2 or 3, it is characterized in that:

The preparation of described TS-1 can adopt the one in hydrothermal synthesis method, microwave heating method, isomorphous substitution method, wherein Ti:Si=0.5wt% ~ 2.5wt%.

5. in accordance with the method for claim 1, it is characterized in that:

Preferably alkene is: one or two or more kinds in propenyl chloride, tetrahydrobenzene or vinylbenzene;

Preferably oxygenant is: one or both in hydrogen peroxide and carbamide peroxide.

6., according to the method described in claim 1 or 5, it is characterized in that:

The mol ratio of the described alkene that adds and water is 10 ~ 1:1, described in the alkene that adds be 0.1 ~ 1molL in the concentration of solvent ^-1; Catalyst levels is 0.05g (g substrate) ^-1~ 0.5g (g substrate) ^-1; The mol ratio of oxygenant and alkene is more than or equal to 1.

7. in accordance with the method for claim 1, it is characterized in that:

Preferably temperature of reaction is 50 DEG C ~ 100 DEG C, and the reaction times is 3h ~ 24h.

8. in accordance with the method for claim 1, it is characterized in that:

The separation of catalyzer can adopt filters or centrifugal, and catalyzer can be reused after roasting.

9. in accordance with the method for claim 1, it is characterized in that:

Described solvent is: the mixture of one or two or more kinds and water in acetone, acetonitrile, methyl alcohol, or pure water, the volume content 10-50% of water in mixture.