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CN-121990582-A - TS-1 titanium silicalite molecular sieve, preparation method thereof and application thereof in catalyzing ethylene sulfite oxidation reaction

CN121990582ACN 121990582 ACN121990582 ACN 121990582ACN-121990582-A

Abstract

The invention relates to the field of molecular sieve synthesis, and discloses a TS-1 titanium silicalite molecular sieve, a preparation method thereof and application thereof in catalyzing ethylene sulfite oxidation reaction. The method comprises the steps of (1) carrying out first mixing on tetrapropylammonium hydroxide and alkyl glucamide in the presence of water to obtain a mixed solution I, carrying out second mixing on tetraethyl silicate, a titanium source and fatty alcohol polyoxyethylene ether phosphate in the presence of an organic solvent to obtain a mixed solution II, (2) carrying out third mixing on the mixed solution I and the mixed solution II to obtain a mixed solution III, and (3) carrying out crystallization on the mixed solution III and roasting the obtained solid product to obtain the TS-1 titanium silicalite molecular sieve. The TS-1 titanium silicalite molecular sieve prepared by the method has high conversion rate of ethylene sulfite and high selectivity of ethylene sulfate.

Inventors

  • CHEN YUKANG
  • CHEN ZHIWEI

Assignees

  • 岳阳翰康科技有限公司

Dates

Publication Date
20260508
Application Date
20260129

Claims (10)

  1. 1. A process for preparing a TS-1 titanium silicalite molecular sieve, the process comprising: (1) In the presence of water, performing first mixing on tetrapropylammonium hydroxide and alkyl glucamide to obtain a mixed solution I; In the presence of an organic solvent, carrying out second mixing on tetraethyl silicate, a titanium source and fatty alcohol polyoxyethylene ether phosphate to obtain a mixed solution II, wherein the dosage mass ratio of the tetraethyl silicate to the fatty alcohol polyoxyethylene ether phosphate is 1:0.003-0.03; (2) Thirdly, mixing the mixed solution I with the mixed solution II to obtain mixed solution III; (3) Crystallizing the mixed solution III, and roasting the obtained solid product to obtain TS-1 to titanium silicalite molecular sieve; The molar ratio of the tetraethyl silicate to the tetrapropylammonium hydroxide to the titanium source to the alkyl glucamide is 1:0.02-0.5:0.02-0.3:0.01-0.05.
  2. 2. The method according to claim 1, wherein in step (1), the alkyl glucamide is at least one selected from the group consisting of octyl glucamide, lauryl glucamide, myristyl glucamide, stearyl glucamide.
  3. 3. The method according to claim 1 or 2, wherein in the step (1), the fatty alcohol-polyoxyethylene ether phosphate has a structural formula RO (C 2 H 4 O) n PO(OH) 2 , R is an alkyl group of C 12 -C 14 , and n is an integer selected from 3 to 9.
  4. 4. The method according to claim 1 or 2, wherein in step (1), the titanium source is tetrabutyl titanate and/or tetraethyl titanate; and/or the organic solvent is methanol and/or ethanol.
  5. 5. The method according to claim 1 or 2, wherein in step (2), the conditions of the third mixing include a temperature of 75 to 95 ℃ for 10 to 60 minutes.
  6. 6. The method according to claim 1 or 2, wherein in the step (3), the crystallization conditions include a temperature of 180 to 240 ℃ for 140 to 340 hours; and/or the roasting condition comprises that the temperature is 400-600 ℃ and the time is 4-10h.
  7. 7. A TS-1 titanium silicalite molecular sieve prepared by the process of any one of claims 1-6.
  8. 8. The use of the TS-1 titanium silicalite molecular sieve of claim 7 in catalyzing the oxidation of vinyl sulfite.
  9. 9. The method for preparing the vinyl sulfate is characterized by comprising the steps of carrying out oxidation reaction on the vinyl sulfite and hydrogen peroxide in the presence of a catalyst to obtain the vinyl sulfate; The catalyst is the TS-1 titanium silicalite molecular sieve of claim 7.
  10. 10. The method according to claim 9, wherein the molar ratio of the ethylene sulfite to the hydrogen peroxide is 1:1.2-1.4; And/or the oxidation reaction conditions comprise a temperature of 20-70 ℃, a pressure of 0.1-1.0Mpa and a liquid hourly space velocity of 0.1-20h -1 .

Description

TS-1 titanium silicalite molecular sieve, preparation method thereof and application thereof in catalyzing ethylene sulfite oxidation reaction Technical Field The invention relates to the field of molecular sieve synthesis, in particular to a TS-1 titanium silicalite molecular sieve, a preparation method thereof and application thereof in catalyzing ethylene sulfite oxidation reaction. Background The key technology for producing vinyl sulfate (DTD) as an additive of lithium battery electrolyte by oxidizing vinyl sulfite still faces multiple technical bottlenecks at present. The traditional mainstream sodium hypochlorite oxidation method relies on an expensive ruthenium trichloride noble metal catalyst, so that the recovery difficulty is high, the cost is high, a large amount of high-salt wastewater can be generated, the environment-friendly treatment pressure is outstanding, the purity of the product can be influenced by residual sodium, chlorine and other ions in the product, and the high standard requirement of the electrolyte is difficult to meet. The early hydrogen peroxide oxidation system has the problems of long reaction time and easy hydrolysis of the product vinyl sulfate, the intermittent kettle reaction yield is lower, the product is easy to decompose at high temperature or long residence time in the continuous process, and the acid value exceeds the standard. In addition, hydrogen and oxygen are needed in part of the process for generating hydrogen peroxide in situ, so that extremely high explosion safety risks exist, and the contradiction between three-waste emission, cost control and product stability of the traditional process is difficult to reconcile. The advent of titanium silicalite (TS-1) catalytic systems has provided a viable solution to this process. The TS-1 molecular sieve has mild reaction conditions with an oxidation system consisting of hydrogen peroxide by virtue of a unique Si-O-Ti bond structure and shape-selective catalytic performance, and the byproduct is only water, so that the environmental protection problem of the traditional process is avoided from the source. The system does not need noble metal, and the oxidant hydrogen peroxide is green and easy to obtain, so that the production cost can be reduced, and a reliable path is provided for the green industrial production of the vinyl sulfate. However, the synthesis difficulty of the high-performance titanium-silicon molecular sieve still needs to be solved. Disclosure of Invention The invention aims to provide a TS-1 titanium silicalite molecular sieve with high ethylene sulfite conversion rate and high ethylene sulfate selectivity. To achieve the above object, a first aspect of the present invention provides a method for preparing a TS-1 titanium silicalite molecular sieve, the method comprising: (1) In the presence of water, performing first mixing on tetrapropylammonium hydroxide and alkyl glucamide to obtain a mixed solution I; In the presence of an organic solvent, carrying out second mixing on tetraethyl silicate, a titanium source and fatty alcohol polyoxyethylene ether phosphate to obtain a mixed solution II, wherein the dosage mass ratio of the tetraethyl silicate to the fatty alcohol polyoxyethylene ether phosphate is 1:0.003-0.03; (2) Thirdly, mixing the mixed solution I with the mixed solution II to obtain mixed solution III; (3) Crystallizing the mixed solution III, and roasting the obtained solid product to obtain a TS-1 titanium silicalite molecular sieve; The molar ratio of the tetraethyl silicate to the tetrapropylammonium hydroxide to the titanium source to the alkyl glucamide is 1:0.02-0.5:0.02-0.3:0.01-0.05. In a second aspect, the present invention provides a TS-1 titanium silicalite molecular sieve prepared by the method of the first aspect. In a third aspect, the invention provides the use of the TS-1 titanium silicalite molecular sieve according to the second aspect in catalyzing ethylene sulfite oxidation. The fourth aspect of the invention provides a method for preparing vinyl sulfate, comprising the steps of carrying out oxidation reaction on vinyl sulfite and hydrogen peroxide in the presence of a catalyst to obtain vinyl sulfate; The catalyst is the TS-1 titanium silicalite molecular sieve in the second aspect. The method provided by the invention can realize uniform dispersion of titanium and improve the catalytic performance of the TS-1 titanium silicalite molecular sieve, and the TS-1 titanium silicalite molecular sieve prepared by the method provided by the invention is used as a high-efficiency catalyst for oxidizing ethylene sulfite into ethylene sulfate, and has the characteristics of high conversion rate, good selectivity, less side reaction and stable performance. Drawings FIG. 1 is an XRD spectrum of a TS-1 titanium silicalite molecular sieve prepared in example 1 of the present invention; FIG. 2 is an SEM image of a TS-1 titanium silicalite molecular sieve prepared in example 1 acc