Catalyst for ethylene sulfate synthesis and clean synthesis process

Abstract

The present invention discloses a catalyst for the synthesis of vinyl sulfite and a clean synthesis process. The catalyst consists of a support, a metal, and a surface molecular layer. The metal is loaded on the support, and the surface molecular layer is modified on the surface of the metal or the support. The catalyst exhibits hydrophobic or amphiphilic properties. Vinyl sulfite, a solvent, and a small amount of the catalyst are added to a reaction vessel, and then hydrogen peroxide is slowly added. The reaction is carried out at -5 to 15 °C for a certain period of time, and the liquid is separated to obtain vinyl sulfite. The product has the advantages of high purity, high yield, less waste liquid, easy treatment of waste liquid, mild reaction, low cost, etc., and is suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to a catalytic oxidation synthesis catalyst for a lithium battery electrolyte additive. Background Art

[0002] Vinylene sulfate is a new type of lithium-ion battery electrolyte additive, which plays a crucial role in improving the performance of lithium-ion batteries. The preparation methods of vinylene sulfate mainly include addition method, oxidation method, acylation method, substitution method, etc. Among them, the oxidation method is the most commonly used process in industry. At present, most oxidation processes have problems such as high cost and large pollution. The catalytic oxidation process based on hydrogen peroxide is one of the most promising low-cost and green synthesis methods at present.

[0003] Patent CN 111909129 A discloses a method for directly oxidizing hydrogen peroxide to prepare cyclic sulfate esters. Using hydrogen peroxide as an oxidant, the cyclic sulfite esters in organic solvents such as dichloromethane are directly oxidized to cyclic sulfate esters under the catalysis of a solid catalyst. Hydrogen peroxide directly participates in the reaction as an oxidant, without generating sulfate by-products, and the amount of reaction wastewater is small. The product purity > 99.5%, and the yield > 80%.

[0004] Patent CN 110386916 A discloses a method for synthesizing cyclic sulfate esters. Peroxymonosulfuric acid solution is pre-synthesized with sulfuric acid and hydrogen peroxide, and then, in the presence of an organic solvent, a metal inorganic compound and a catalyst, the peroxymonosulfuric acid solution is dropped to carry out a catalytic oxidation reaction with the cyclic sulfite ester to obtain the cyclic sulfate ester.

[0005] In view of the solubility of vinylene sulfate, organic solvents such as dichloromethane are generally used in the current hydrogen peroxide oxidation process to dissolve the vinylene sulfate product in the reaction process, so as to avoid the precipitation of the product during the reaction and affect the uniform progress of the reaction. However, most catalysts have low dispersibility in organic solvents such as dichloromethane and cannot fully contact with the raw materials in the organic solvent. In addition, hydrogen peroxide dissolves in the aqueous phase and cannot fully contact with the raw materials in the organic solvent either. As a result, the reaction activity is relatively low. To improve the reaction activity, there are two common methods: 1) raising the reaction temperature to above 30 °C or 40 °C, which will cause a large amount of decomposition of raw materials or products, resulting in a significant reduction in yield, even lower than 50%. 2) significantly increasing the catalyst dosage, with the catalyst mass accounting for more than 50% of the raw material mass, which will lead to higher costs and more catalyst solid waste; at the same time, even if the catalyst dosage is significantly increased, the reaction temperature generally has to be above 20 °C to ensure the effective progress of the reaction, resulting in the inability to further improve the product yield in essence. Summary of the Invention

[0006] The main problem to be solved by the present invention is to provide a catalyst and method for the green preparation of ethylene sulfate with lower cost. The ethylene sulfate synthesis catalyst includes a support, a metal oxide, and a surface molecular layer. The metal oxide is loaded on the support, and the surface molecular layer is modified on the surface of the metal and / or the support. The catalyst has hydrophobic or amphiphilic properties. The surface molecular layer is connected to the metal oxide and / or the support through Si-O bonds. The modification form of the surface molecular layer on the surface of the metal or the support includes incomplete wrapping or complete wrapping. The loading form of the metal oxide on the support includes at least one of unit point embedding in the framework, single atom loading, cluster loading, and nanoparticle loading. The content of the metal element in the whole catalyst is 0.01-50 wt%.

[0007] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the support contains a porous structure material.

[0008] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the porous structure material is at least one of mesoporous carbon, mesoporous silicon, all-silica molecular sieve, silica-alumina molecular sieve, iron-silica molecular sieve, titanium-silica molecular sieve, copper-silica molecular sieve, MOF (metal-organic framework material), COF (covalent organic framework material), and HOF (hydrogen bond organic framework material).

[0009] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the metal oxide includes at least one of metal ions, simple substances, oxides, and hydroxides of Au, Ag, Pt, Pd, Ru, Rh, Si, Fe, Co, Ni, Cu, Ti, Mn, Sn, Zn, Zr, Mo, Ce, V, Mg, and Ca.

[0010] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the wrapping thickness of the surface molecular layer is 0.0001-2 layers.

[0011] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the surface molecular layer is at least one of hydrophobic silane, amphiphilic silane, and a mixture of hydrophobic silane and hydrophilic silane.

[0012] Further, the above-mentioned ethylene sulfate synthesis catalyst is characterized in that the general formula of the silane molecule includes SiOxCnHm, SiOxCnHm(NH2)y, SiOxCnHm(COOH)y, SiCnHm, SiCnHm, SiCnHm(NH2)y, SiCnHm(COOH)y; x = 1-3, y = 1-20, n = 1-100, m = 1-100.

[0013] Another object of the present invention is to provide the application of the ethylene sulfate synthesis catalyst in the synthesis of ethylene sulfate.

[0014] Another object of the present invention is to provide a clean process for synthesizing vinylene sulfate. Add vinylene sulfite, a solvent and the catalyst for synthesizing vinylene sulfate into a reaction vessel, then slowly add hydrogen peroxide. After stirring for a certain time at a certain temperature, stop stirring and separate the liquid to obtain vinylene sulfate.

[0015] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the organic solvent includes at least one of dichloromethane, dichloroethane, petroleum ether, dimethyl carbonate, and tetrahydrofuran.

[0016] Another object of the present invention is to provide another clean process for synthesizing vinylene sulfate as described above. Add vinylene sulfite and the catalyst for synthesizing vinylene sulfate according to any one of claims 1-6 into a reaction vessel, then slowly add hydrogen peroxide. After stirring for a certain time at a certain temperature, stop stirring and separate the liquid to obtain vinylene sulfate.

[0017] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the concentration of hydrogen peroxide is preferably 5-35 wt%, and it is added to the reaction solution in a slow dropping manner.

[0018] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the mass ratio of the catalyst to the cyclic sulfite is preferably 1:20 to 1:100.

[0019] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the mass ratio of hydrogen peroxide to the cyclic sulfite is preferably 1:1 to 3:1.

[0020] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the reaction temperature is preferably -5 to 15 °C.

[0021] Further, in the above-mentioned clean process for synthesizing vinylene sulfate, the reaction time is 1-48 hours.

[0022] The main advantages of the present invention are as follows:

[0023] By using a hydrophobic or amphiphilic catalyst, the raw materials in the organic solvent can be fully contacted with hydrogen peroxide and the catalyst, optimizing the catalytic reaction kinetics.

[0024] Compared with the existing hydrogen peroxide oxidation process, the core advantages of the present invention are that it can have the advantages of less catalyst consumption, mild reaction conditions, and high yield:

[0025] 1) Cost reduction: Under the low temperature condition of -5 to 15 °C, the consumption of the catalyst is greatly reduced, from more than 50 wt% to less than 5 wt%, the cost is greatly reduced, and the solid waste is greatly reduced.

[0026] 2) Higher yield: Under the condition of catalyst dosage of 1-5 wt%, the reaction conditions are milder, and the yield increases significantly from less than 50% to more than 80%. Detailed implementation method

[0027] Example 1

[0028] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 1 g of mesoporous silica-supported nano-titanium dioxide catalyst (modified with octadecyltrimethylsilane) into a flask, slowly dropwise add 80 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 5 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain 48 g of DTD product, GC purity > 99.85%, and the yield is 83.8%.

[0029] Preparation method of mesoporous silica-supported nano-titanium dioxide catalyst: Add 20 mL of benzyl alcohol, 20 mL of oleylamine, 5 mL of titanium isopropoxide and 20 g of MCM-41 mesoporous silica material into the PTFE liner of a 100 mL autoclave, stir at room temperature for 5 minutes, then cover the lid and put it into an oven, react at 150 °C for 8 hours, cool to room temperature, wash with ethanol 3 times, and disperse in 100 mL of ethanol to obtain the mesoporous silica-supported nano-titanium dioxide catalyst.

[0030] Preparation method of mesoporous silica-supported nano-titanium dioxide catalyst (modified with octadecyltrimethylsilane): Add octadecyltrimethylsilane reagent (the molar ratio of octadecyltrimethylsilane to titanium isopropoxide is 1:1) into the above ethanol solution, stir at 50 °C for 12 hours to obtain the octadecyltrimethylsilane-bonded mesoporous silica-supported nano-titanium dioxide catalytic material.

[0031] To compare the results of hydrophobic modification, we carried out the following comparative experiments

[0032] Comparative example 1

[0033] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 10 g of mesoporous silica-supported nano-titanium dioxide catalyst into a flask, slowly dropwise add 80 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 5 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0034] Comparative example 2

[0035] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 10 g of mesoporous silica-supported nano-titanium dioxide catalyst into a flask, slowly dropwise add 80 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0036] Comparative Example 3

[0037] Add 50 g of vinylene sulfite, 300 ml of dichloromethane and 5 g of mesoporous silica-supported nano-titanium dioxide catalyst into a flask, slowly dropwise add 80 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0038] Comparative Example 4

[0039] Add 50 g of vinylene sulfite, 300 ml of dichloromethane and 1 g of mesoporous silica-supported nano-titanium dioxide catalyst into a flask, slowly dropwise add 80 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0040] The experimental results are as follows:

[0041]

[0042] Example 2

[0043] Add 50 g of vinylene sulfite, 300 ml of dichloroethane and 1 g of amphiphilic copper-silicate molecular sieve-supported RuO2 catalyst (modified with dodecyltrimethylsilane and 3-aminopropyltriethoxysilane in a molar ratio of 1:1) into a flask, slowly dropwise add 100 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 12 °C, end the reaction after stirring for 5 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain 51 g of the DTD product, with a yield of 89.00% and a GC purity > 99.51%.

[0044] Preparation method of the copper-silicate molecular sieve-supported RuO2 catalyst: Add 1 g of glucose, 20 g of copper-silicate molecular sieve, and 60 mL of 0.2 wt% RuCl3 aqueous solution into the polytetrafluoroethylene liner of a 100 mL autoclave, stir at room temperature for 5 minutes, then cover the lid and place it in an oven, react at 150 °C for 10 hours, cool to room temperature, wash with ethanol 3 times, and disperse in 100 mL of ethanol to obtain the copper-silicate molecular sieve-supported RuO2 catalyst.

[0045] Amphiphilic ruthenium catalyst supported on copper-silica molecular sieve (modified with octadecyltrimethylsilane and 3-aminopropyltriethoxysilane in a molar ratio of 1:1): Add dodecyltrimethylsilane and 3-aminopropyltriethoxysilane (the molar ratio of dodecyltrimethylsilane to 3-aminopropyltriethoxysilane is 1:1, and the molar ratio of dodecyltrimethylsilane to RuCl3 is 1:1) to the above ethanol solution, stir at 50 °C for 12 hours to obtain an amphiphilic ruthenium catalyst supported on copper-silica molecular sieve (modified with octadecyltrimethylsilane and 3-aminopropyltriethoxysilane in a molar ratio of 1:1).

[0046] To compare the results of hydrophobic modification, we conducted the following comparative experiments

[0047] Comparative Example 5

[0048] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 10 g of ruthenium catalyst supported on copper-silica molecular sieve to the flask, slowly dropwise add 100 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 5 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0049] Comparative Example 6

[0050] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 10 g of ruthenium catalyst supported on copper-silica molecular sieve to the flask, slowly dropwise add 100 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0051] Comparative Example 7

[0052] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 5 g of ruthenium catalyst supported on copper-silica molecular sieve to the flask, slowly dropwise add 100 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0053] Comparative Example 8

[0054] Add 50 g of ethylene sulfite, 300 ml of dichloromethane and 1 g of ruthenium catalyst supported on copper-silica molecular sieve to the flask, slowly dropwise add 100 g of 30 wt% hydrogen peroxide, start stirring, control the temperature at 30 °C, end the reaction after stirring for 12 h, filter by suction and then separate the layers, take the lower organic solvent, and rotary evaporate at 30 °C to obtain the DTD product.

[0055] The experimental results are as follows:

[0056]

Claims

1. Application of a catalyst for ethylene sulfate synthesis in the synthesis of ethylene sulfate, characterized in that: Vinylene sulfite, a solvent, and a catalyst for the synthesis of ethylene sulfate are added to a reaction vessel, and then hydrogen peroxide is slowly added. After stirring for a certain time at a certain temperature, stirring is stopped, and the liquid is separated to obtain ethylene sulfate; the catalyst includes a carrier, a metal oxide, and a surface molecular layer. The metal oxide is supported on the carrier, and the surface molecular layer is modified on the surface of the metal and / or the carrier. The catalyst has hydrophobic or amphiphilic properties; the surface molecular layer is connected to the metal oxide and / or the carrier by Si-O bonds, and the modification form of the surface molecular layer on the surface of the metal or the carrier includes incomplete wrapping or complete wrapping; The loading form of the metal oxide on the carrier includes at least one of single-site embedding in the framework, single-atom loading, cluster loading, and nanoparticle loading, and the content of the metal element in the whole catalyst is 0.01-50 wt%; The carrier contains a porous structure material, and the porous structure material is at least one of mesoporous carbon, mesoporous silicon, all-silica molecular sieve, silica-alumina molecular sieve, iron-silica molecular sieve, titanium-silica molecular sieve, copper-silica molecular sieve, MOF, COF, HOF; The metal oxide includes at least one of oxides of Au, Ag, Pt, Pd, Ru, Rh, Fe, Co, Ni, Cu, Ti, Mn, Sn, Zn, Zr, Mo, Ce, V, Mg, Ca; The surface molecular layer is at least one of a mixture of hydrophobic silane and hydrophilic silane, hydrophobic silane, and amphiphilic silane.

2. The application according to claim 1, characterized in that The general formula of silane molecules includes SiO x C n H m 、SiO x C n H m (NH2) y 、SiO x C n H m (COOH) y 、SiC n H m 、SiC n H m (NH2) y 、SiC n H m (COOH) y at least one of them; wherein, x = 1 - 3, y = 1 - 20, n = 1~100, m = 1 - 100.

3. The application according to claim 1, characterized in that: The solvent includes at least one of dichloromethane, dichloroethane, petroleum ether, dimethyl carbonate, and tetrahydrofuran.

4. The application according to any one of claims 1 to 3, characterized in that: The concentration of hydrogen peroxide is 5-35 wt%, and it is added to the reaction solution by slow dropping.

5. The application according to any one of claims 1 to 3, characterized in that: The mass ratio of the catalyst to vinylene sulfite is 1:20 to 1:

100.

6. The application according to any one of claims 1-3, characterized in that: The mass ratio of hydrogen peroxide to vinylene sulfite is 1:1 to 3:

1.

7. The application according to any one of claims 1 to 3, characterized in that: The synthesis reaction temperature is 5-15 °C.

8. The application according to any one of claims 1-3, characterized in that: The synthesis reaction time is 1-48 hours.

9. Use of a catalyst for the synthesis of ethylene sulfate in the synthesis of ethylene sulfate, characterized in that: Vinylene sulfite and a catalyst for the synthesis of ethylene sulfate are added to a reaction vessel, and then hydrogen peroxide is slowly added. After stirring for a certain time at a certain temperature, stirring is stopped, and the liquid is separated to obtain ethylene sulfate; The catalyst includes a carrier, a metal oxide, and a surface molecular layer. The metal oxide is supported on the carrier, and the surface molecular layer is modified on the surface of the metal and / or the carrier. The catalyst has hydrophobic or amphiphilic properties; the surface molecular layer is connected to the metal oxide and / or the carrier by Si-O bonds, and the modification form of the surface molecular layer on the surface of the metal or the carrier includes incomplete wrapping or complete wrapping; The loading form of the metal oxide on the carrier includes at least one of single-site embedding in the framework, single-atom loading, cluster loading, and nanoparticle loading, and the content of the metal element in the whole catalyst is 0.01-50 wt%; The carrier contains a porous structure material, and the porous structure material is at least one of mesoporous carbon, mesoporous silicon, all-silica molecular sieve, silica-alumina molecular sieve, iron-silica molecular sieve, titanium-silica molecular sieve, copper-silica molecular sieve, MOF, COF, HOF; The metal oxide includes at least one of oxides of Au, Ag, Pt, Pd, Ru, Rh, Fe, Co, Ni, Cu, Ti, Mn, Sn, Zn, Zr, Mo, Ce, V, Mg, and Ca; The surface molecular layer is at least one of a mixture of hydrophobic silane and hydrophilic silane, hydrophobic silane, and amphiphilic silane.

10. The application according to claim 9, characterized in that: The concentration of hydrogen peroxide is 5-35 wt%, and it is added to the reaction solution in a slow dropping manner.

11. The application according to claim 9, characterized in that: The mass ratio of the catalyst to vinylene sulfite is 1:20 to 1:

100.

12. The application according to claim 9, characterized in that: The mass ratio of hydrogen peroxide to vinylene sulfite is 1:1 to 3:

1.

13. The application according to claim 9, wherein: The synthesis reaction temperature is 5-15 °C.

14. The application according to claim 9, wherein: The synthesis reaction time is 1-48 hours.

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