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CN-122006784-A - Acidic solid catalyst and preparation method and application thereof

CN122006784ACN 122006784 ACN122006784 ACN 122006784ACN-122006784-A

Abstract

The invention belongs to the field of fine chemical engineering, and relates to an acidic solid catalyst, a preparation method and application thereof. The acidic solid catalyst comprises a sulfonated modified SBA-15 full-silicon mesoporous molecular sieve, and the content of surface sulfonic acid groups of the acidic solid catalyst is 1.6-2.8mmol/g, preferably 1.8-2.7mmol/g, and more preferably 2.1-2.6mmol/g. The preparation method of the acidic solid catalyst comprises the following steps of carrying out contact reaction on the SBA-15 all-silicon mesoporous molecular sieve and a sulfonating agent to obtain the acidic solid catalyst. The acidic solid catalyst provided by the invention has the advantages of stable structure, good high temperature resistance, no toxicity, no deformation and no swelling in the reaction process, and easy recovery after the reaction, and can be used for the methacrylate reaction, so that higher methacrylic acid conversion rate, methacrylate selectivity and catalyst stability can be obtained.

Inventors

  • LIU HONGMEI
  • SHAO YUN
  • JIANG SHAN
  • LIU DONGBING

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (16)

  1. 1. An acidic solid catalyst, characterized in that the acidic solid catalyst comprises a sulfonated modified SBA-15 all-silicon mesoporous molecular sieve, and the content of surface sulfonic acid groups of the acidic solid catalyst is 1.6-2.8mmol/g, preferably 1.8-2.7mmol/g, and more preferably 2.1-2.6mmol/g.
  2. 2. The acidic solid catalyst of claim 1, wherein the sulfonation modified SBA-15 all-silicon mesoporous molecular sieve is a sulfonating agent treated SBA-15 all-silicon mesoporous molecular sieve.
  3. 3. The acidic solid catalyst according to claim 2, wherein the sulfonating agent is a halosulfonic acid, preferably at least one selected from the group consisting of fluorosulfonic acid, chlorosulfonic acid, bromosulfonic acid and iodized sulfonic acid.
  4. 4. The acidic solid catalyst according to claim 2, wherein the sulphonation modified SBA-15 all-silicon mesoporous molecular sieve has an average pore diameter of 4.0-6.5nm, preferably 5.0-6.0nm, a specific surface area of 500-920m 2 /g, preferably 600-850m 2 /g, a pore volume of 0.9-1.3cm 3 /g, preferably 1.0-1.2cm 3 /g.
  5. 5. The acidic solid catalyst of any one of claims 1-4, wherein the acidic solid catalyst further comprises a Lewis acid that forms a complex with sulfonic acid groups on the sulfonation modified SBA-15 all-silicon mesoporous molecular sieve.
  6. 6. The acidic solid catalyst according to claim 5, wherein the Lewis acid is selected from at least one of tin tetrachloride, aluminum trichloride, and ferric bromide.
  7. 7. The acidic solid catalyst according to claim 5, wherein the content of Lewis acid in the acidic solid catalyst is 4 to 16wt%, preferably 5 to 14wt%, more preferably 6 to 12wt%, based on the total mass of the acidic solid catalyst.
  8. 8. The acidic solid catalyst according to claim 5, wherein the acidic solid catalyst has an average pore diameter of 3.5-6.0nm, preferably 4.0-5.5nm, a specific surface area of 400-900m 2 /g, preferably 500-750m 2 /g, a pore volume of 0.7-1.2cm 3 /g, preferably 0.8-1.1cm 3 /g, a surface acid amount of 2.0-3.5mmol/g, preferably 2.2-3.3mmol/g, more preferably 2.5-3.0mmol/g.
  9. 9. The process for producing an acidic solid catalyst according to any one of claims 1 to 8, comprising the steps of: and (3) carrying out contact reaction on the SBA-15 all-silicon mesoporous molecular sieve and a sulfonating agent to obtain the acidic solid catalyst.
  10. 10. The preparation method according to claim 9, wherein the weight ratio of the SBA-15 fully-silica mesoporous molecular sieve to the sulfonating agent is 1 (0.3-1.2), preferably 1 (0.4-1.0), more preferably 1 (0.5-0.9).
  11. 11. The preparation method according to claim 9, wherein the conditions of the contact reaction include a reaction temperature of 0 to 40 ℃ and a reaction time of 0.2 to 8 hours.
  12. 12. The production method according to any one of claims 9 to 11, wherein the production method further comprises the steps of: (1) The Lewis acid solution and the SBA-15 full-silicon mesoporous molecular sieve modified by sulfonation are subjected to contact reaction; (2) And filtering, washing and drying to obtain the acidic solid catalyst.
  13. 13. The process according to claim 12, wherein in the step (1), the solvent of the Lewis acid solution is selected from at least one of methanol, ethanol and isopropanol, and the mass concentration of the Lewis acid is 1.3 to 3.5%; the weight ratio of the sulfonation modified SBA-15 full-silicon mesoporous molecular sieve to the Lewis acid solution is 1 (5-50); The conditions of the contact reaction comprise the temperature of 30-80 ℃ and the time of 2-8h.
  14. 14. The preparation method according to claim 12, wherein in the step (2), the drying condition comprises a temperature of 80-150 ℃ for 1-20 hours.
  15. 15. The use of the acidic resin catalyst according to any one of claims 1 to 8 in a methacrylate synthesis reaction, preferably wherein the methacrylate is methyl methacrylate.
  16. 16. A method for preparing methacrylic acid ester is characterized by comprising the steps of carrying out contact reaction on methacrylic acid, low-carbon alcohol and a catalyst; Preferably, the conditions for the contact reaction include a temperature of 40-150 ℃, preferably 60-120 ℃, a pressure of 0.01-5.0MPa, preferably 0.1-3.0MPa, a mass space velocity of methacrylic acid of 0.01-30h -1 , preferably 0.1-10h -1 , a mass space velocity of lower alcohols of 0.01-50h -1 , preferably 0.1-30h -1 , preferably alcohols of C 1 -C 4 , more preferably methanol.

Description

Acidic solid catalyst and preparation method and application thereof Technical Field The invention belongs to the field of fine chemical engineering, and particularly relates to an acidic solid catalyst, a preparation method thereof and application of the catalyst in methacrylate synthesis reaction. Background As an important organic chemical product and an important organic chemical raw material, the industrial production level and the production capacity of Methyl Methacrylate (MMA) have important influence on the development of chemical industry in China. MMA is mainly used in industries such as organic glass (PMMA), paint, textile, adhesive, leather, papermaking, floor polishing, unsaturated resin, methacrylic acid higher esters, wood impregnating compound, printing and dyeing auxiliary agent, plasticizer of plastics and the like. In recent years, the demands of MMA polymers, profiles, plates, coatings, emulsions and the like at home and abroad are increased, the application fields are continuously widened, and the rapid development of MMA industry is promoted. At present, the domestic methyl methacrylate production technology is still in the starting stage. The development of the methacrylate catalyst with independent intellectual property rights and the matched process are the development demands of MMA production industry in China. Esterification catalysts are the core technology for MMA production. The traditional catalyst used to catalyze the esterification of methacrylic acid with methanol is concentrated sulfuric acid. The catalyst has high catalytic activity and low cost, but the characteristics of strong oxidizing property, dehydration property, dissolution of the concentrated sulfuric acid in a reaction system and the like also bring trouble to equipment corrosion and subsequent treatment. Therefore, it is still of positive interest to find a catalyst which combines strong catalytic activity, high selectivity and easy separation from the reaction system. Esterification catalysts for heterogeneous reactions are currently a relatively active area of research. At present, the reported catalyst capable of replacing concentrated sulfuric acid comprises strong acid type ion exchange resin, heteropolyacid, ionic liquid, solid super acid and the like, so that a good effect is obtained. Among them, strongly acidic ion exchange resins have attracted much attention due to their insolubility in the reaction system, good stability, high selectivity, low cost, easy separation, and the like. The strong acid cation exchange resin is a high molecular material containing acidic groups, and is not easy to corrode production equipment because the strong acid cation exchange resin essentially belongs to a solid catalyst, so that the strong acid cation exchange resin has a large application in industrial production. However, the reaction speed of the catalyst is slower, and the yield of the ester is lower. The cation exchange resin has the advantages of good stability, high selectivity, low cost, easy separation and the like in the esterification reaction. However, the cation exchange resin itself has poor heat resistance (generally suitable for esterification reactions at temperatures below 150 ℃), small specific surface area and pore volume, and is susceptible to swelling, and has poor activity and low ester yield when used as an esterification catalyst. Compared with the resin catalyst, the hydrogen zeolite molecular sieve has a certain pore channel structure and surface acidity, and is suitable for catalyzing esterification reaction of small molecules. However, the zeolite molecular sieve has smaller pore canal size (0.5-0.7 nm), can inhibit the diffusion of macromolecular products in the reaction, has smaller number of acid sites on the surface of the zeolite molecular sieve, and has lower efficiency of catalyzing the esterification reaction. With the increasing demand of methyl methacrylate, the environment-friendly synthesis process has wide prospect. For researchers, developing a methyl methacrylate synthesis reaction catalyst with excellent performance, improving the catalytic efficiency and inhibiting the generation of byproducts is an important working direction in the future. Disclosure of Invention The invention aims to solve the problems of low methacrylic acid conversion rate, low methacrylic acid yield and poor catalyst stability in the existing methacrylic acid ester production process, and provides an acidic solid catalyst, a preparation method and application thereof. The catalyst is used for the methacrylate reaction, and can obtain higher methacrylic acid conversion rate, methacrylate selectivity and catalyst stability. In order to achieve the above object, a first aspect of the present invention provides an acidic solid catalyst comprising a sulfonation modified SBA-15 all-silicon mesoporous molecular sieve, the acidic solid catalyst having a surface sulfonic acid group content of 1.6 to 2.8mm