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CN-117797805-B - Catalyst, preparation method and application thereof

CN117797805BCN 117797805 BCN117797805 BCN 117797805BCN-117797805-B

Abstract

The invention relates to the technical field of catalysts, in particular to a catalyst and a preparation method and application thereof, wherein the catalyst comprises active components Ta, W, al and an auxiliary agent M, wherein M is selected from at least one of alkali metal elements and Ag, the molar ratio of M to Ta, W and Al is 1 (1-13) (4-34) (100-573) calculated by metal elements, and the Ru content accounts for less than 0.1 mol% of the total content of all metal elements. The catalyst provided by the invention has good catalytic performance in the reaction of synthesizing 2-methoxypropene.

Inventors

  • SHANG ZHOU
  • XU YONGZHI
  • YANG JUN
  • YUAN YUKUN

Assignees

  • 宁夏天新药业有限公司

Dates

Publication Date
20260505
Application Date
20231114

Claims (20)

  1. 1. Catalyst for the preparation of 2-alkoxypropenes from 2-alkoxypropanes, characterized in that it comprises active components Ta, W, al and an auxiliary M, where M is selected from K and/or Ag, the molar ratio of M to Ta, W, al being 1 (3-10): (12-26): (162-400), calculated as metal element, and the catalyst being free of Ru.
  2. 2. The catalyst according to claim 1, wherein the specific surface area of the catalyst is 20-250m 2 /g.
  3. 3. The catalyst of claim 1, wherein M is present in the form of carbonate and/or oxide; and/or Ta is present in the form of Ta 2 O 5 ; And/or W is in the form of WO 3 ; and/or, al is present in the form of Al 2 O 3 .
  4. 4. A process for preparing a catalyst for preparing 2-alkoxy propylene from 2-alkoxy propane, which is characterized by comprising the steps of mixing an M source, a tantalum source and a tungsten source with an aluminum source to form a jelly, drying and calcining the obtained jelly, wherein M is selected from K and/or Ag, and the M source, the tantalum source, the tungsten source and the aluminum source are used in amounts such that the molar ratio of M to Ta, W and Al is 1 (3-10): (12-26): (162-400) in terms of metal elements in the catalyst.
  5. 5. The method of claim 4, wherein the M source is a water soluble salt of M.
  6. 6. The method of claim 5, wherein the M source is at least one of a halide, acetate, and nitrate of M.
  7. 7. The method of claim 4, wherein the tantalum source is at least one of tantalum ethoxide, tantalum isopropoxide, and tantalum pentachloride.
  8. 8. The method of claim 7, wherein the tantalum source is tantalum pentachloride.
  9. 9. The method of claim 4, wherein the tungsten source is a water soluble salt of tungsten.
  10. 10. The method of claim 9, wherein the tungsten source is at least one of ammonium tungsten oxide, ammonium paratungstate, and ammonium metatungstate.
  11. 11. The method of claim 4, wherein the aluminum source is a water soluble salt of aluminum.
  12. 12. The method of claim 11, wherein the aluminum source is at least one of aluminum trichloride, aluminum sulfate, and aluminum nitrate.
  13. 13. The method of claim 4, wherein the drying temperature is 80-150 ℃.
  14. 14. The method of claim 13, wherein the drying temperature is 100-130 ℃.
  15. 15. The method of claim 4, wherein the drying time is 3-20 hours.
  16. 16. The method of claim 15, wherein the drying time is 3-5 hours.
  17. 17. The method of claim 4, wherein the calcination temperature is 400-800 ℃.
  18. 18. The method of claim 17, wherein the calcination temperature is 500-700 ℃.
  19. 19. The method of claim 4, wherein the calcination is for a time of 1-8 hours.
  20. 20. The method of claim 19, wherein the calcination is for a period of 3-5 hours.

Description

Catalyst, preparation method and application thereof Technical Field The invention relates to the technical field of catalysts, in particular to a catalyst and a preparation method and application thereof. Background 2-Methoxypropene is the simplest alkenyl ether, has very wide application, and is a key intermediate raw material in the synthesis of various medicines, dyes and materials such as clarithromycin, pseudoionone, vitamins, carotene and the like. Because of the great demand, the research and development of a simple, efficient and large-scale industrialized 2-methoxy propylene synthesis method is particularly important. The synthesis of 2-methoxypropene by gas phase pyrolysis is a widely used method at present. The method uses a specific cracking catalyst, and under a certain temperature, raw material 2, 2-dimethoxy propane directly removes one molecule of methanol to generate target product 2-methoxy propylene after passing through a catalyst bed layer, and the reaction equation is as follows: Compared with other methods such as a direct synthesis method, a liquid phase pyrolysis method and the like, the gas phase pyrolysis method has the advantages of simple post-treatment operation, easy separation of products, no need of using an organic solvent and the like, so that attention is paid, and the research focus of the method is on the preparation process of the catalyst, and the selectivity of the catalyst and the yield of 2-methoxypropene are the most important targets of investigation. CN1218791A discloses a process for the preparation of enol ethers by gas phase reaction of acetals/ketals over highly porous oxide heterogeneous catalysts selected from magnesia, alumina, silica, zinc oxide, titania or mixtures thereof at a reaction temperature of 220-300 ℃, however even though the conversion of 2, 2-dimethoxypropane is improved by separation of by-products and recovery of the recycled raw materials, the conversion is still below 80%. CN1660742a discloses a process for synthesizing 2-alkoxyl propylene, which is carried out in a tower reactor with a length of 1m, wherein the catalyst is acid ceramic, cation resin, heteropolyacid or acid molecular sieve, and the yield is the best when the acid ceramic is used for preparing 2-methoxyl propylene and reaches 95.6%. Although various related catalysts have been reported in literature and patents for synthesizing 2-methoxypropene by a gas phase cracking method, development of a catalytic system with higher activity and selectivity is still of great importance for reducing production costs. Disclosure of Invention The invention aims to solve the problems that the conversion rate of 2, 2-dimethoxy propane and the selectivity and yield of 2-methoxy propylene are required to be further improved in the prior art, and provides a catalyst, a preparation method and application thereof. In order to achieve the above object, the first aspect of the present invention provides a catalyst, wherein the catalyst comprises active components Ta, W, al and an auxiliary agent M, wherein M is at least one selected from alkali metal elements and Ag, the molar ratio of M to Ta, W, al is 1 (1-13): (4-34): (100-573), calculated as metal elements, and the Ru content is 0.1 mol% or less of the total content of all metal elements. The second aspect of the invention provides a method for preparing a catalyst, which comprises the steps of mixing an M source, a tantalum source, a tungsten source and an aluminum source to form a jelly, drying and calcining the obtained jelly, wherein M is at least one of alkali metal element and Ag, and the dosage of the M source, the tantalum source, the tungsten source and the aluminum source is such that the molar ratio of M to Ta, W and Al is 1 (1-13): (4-34): (100-573) in terms of metal element in the catalyst. In a third aspect, the present invention provides a catalyst prepared by the preparation method as described above. In a fourth aspect the present invention provides the use of the catalysts of the first and third aspects of the invention in a catalytic gas phase cracking reaction, preferably in the preparation of 2-alkoxypropene from 2-alkoxypropane, more preferably in the preparation of 2-methoxypropene from 2, 2-dimethoxypropane. In a fifth aspect the present invention provides a process for the synthesis of 2-methoxypropene, wherein the process comprises subjecting 2, 2-dimethoxypropane to a gas phase cleavage reaction in the presence of a catalyst comprising the catalysts according to the first and third aspects of the present invention. Through the technical scheme, the catalyst provided by the invention has good catalytic performance in the reaction of synthesizing 2-methoxypropene, and in a preferred embodiment, the conversion rate of 2, 2-dimethoxypropane is more than 85%, and the selectivity of 2-methoxypropene is more than 90%. Detailed Description The endpoints and any values of the ranges disclosed herein are not limited to the