Process for the production of disilanes from ethylsilane

Abstract

This invention relates to the field of inorganic synthesis, specifically disclosing a method for generating propane and butane from ethoxysilane, comprising the following steps: ethoxysilane and hydrogen are introduced into a fixed-bed reactor at a pressure of 0.3-0.8 MPa for a catalytic reaction to generate propane and butane; the fixed-bed reactor is loaded with a catalyst; the catalytic reaction temperature is 150-220℃, and the space velocity of the introduced ethoxysilane and hydrogen is 600-800 h⁻¹. ‑1 This invention solves the problems of difficult selectivity control and low yield in the synthesis of higher-order silanes, providing high-purity silane precursors for the semiconductor industry.

Description

Technical Field

[0001] This invention relates to the field of inorganic synthesis, and more particularly to a method for generating propane and butane from ethsilane. Background Technology

[0002] Higher-order silanes (such as propane and butane) are key raw materials for the preparation of silicon-based thin films and dopants for electronic devices, but their synthesis faces challenges: 1. Limitations of traditional methods: Currently, propionyl silane and butyl silane are mainly prepared by reacting magnesium silicide with acid, but the product is a mixed silane (containing methylene silane to pentadecyl silane), which has high separation costs, and butyl silane is easily decomposed at room temperature.

[0003] 2. Selectivity is difficult to control: Although existing catalytic processes (such as silane polymerization) can directionally generate silane or propane, the selectivity of butane is generally less than 20%.

[0004] 3. Stability issues: Butylsilane is spontaneously combustible in air, so high temperatures or oxidizing environments must be avoided during synthesis. Summary of the Invention

[0005] This invention provides a method for generating propane and butane from ethylsilane at a low reaction temperature, avoiding an oxidizing environment, and exhibiting high selectivity for butane.

[0006] The technical solution of this invention: A method for generating propane and butane from ethoxysilane includes the following steps: ethoxysilane and hydrogen are catalytically reacted in a fixed-bed reactor at a pressure of 0.3-0.8 MPa to generate propane and butane; a catalyst is loaded in the fixed-bed reactor; the catalytic reaction temperature is 150-220℃, and the space velocity of the ethoxysilane and hydrogen is 600-800 h⁻¹. -1 .

[0007] Preferably, the volume ratio of silane to hydrogen is 80-90:10-20. More preferably, it is 85:15.

[0008] Preferably, the catalyst is a molecular sieve-supported platinum-cobalt bimetallic nanoparticle.

[0009] Preferably, the molecular sieve support has a SiO2 / Al2O3 molar ratio of 1000-1500 and is loaded with 0.5-1.5 wt% platinum-cobalt bimetallic nanoparticles, with a platinum to cobalt molar ratio of 1-2:1.

[0010] Preferably, the surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles is coated with thermosensitive polymer gel microspheres, the mass of which is 0.2-0.4% of the mass of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles, and the phase transition temperature is 25-35℃.

[0011] Preferably, the temperature-sensitive polymeric gel microspheres are poly(N-isopropylacrylamide) gel microspheres, and the molecular sieve is an HZSM, type A, type X, or type Y molecular sieve.

[0012] Preferably, the catalyst preparation method includes the following steps: Molecular sieves were immersed in a chloroplatinic acid / cobalt nitrate solution for 10-18 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.05-0.1 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:1. After immersion, the sieves were calcined at 500-550℃ in air for 4-5 hours to obtain zeolite-cobalt bimetallic nanoparticles supported on the molecular sieves. Thermosensitive polymeric gel microspheres were added into the pores of platinum-cobalt bimetallic nanoparticles supported on molecular sieves.

[0013] Preferably, the specific method for adding thermosensitive polymeric gel microspheres to the pores of platinum-cobalt bimetallic nanoparticles supported on molecular sieves includes the following steps: Preparation of soaking solution: Disperse thermosensitive polymeric gel microspheres in anhydrous ethanol to prepare a dispersion with a mass concentration of 2-3%; Equal volume impregnation: The dispersion is added dropwise to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve while stirring, and allowed to stand at room temperature for 4-6 hours for adsorption. Drying and curing: Drying at 60℃ under a nitrogen atmosphere for 12-18 hours to solidify the temperature-sensitive polymer gel microspheres and anchor them on the pore surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

[0014] Preferably, the mass ratio of the dispersion to the molecular sieve-loaded platinum-cobalt bimetallic nanoparticles is 3-5:5-7, and the dropping time is 4-8 hours.

[0015] Preferably, the selectivity of the butyrylane is not less than 24%.

[0016] The beneficial effects of this invention are: This invention solves the problems of difficult selectivity control and low yield in the synthesis of higher-order silanes, providing high-purity silane precursors for the semiconductor industry. The invention utilizes a low reaction temperature, avoids an oxidizing environment, and achieves high selectivity for butyryl silanes, with a selectivity of not less than 24%.

[0017] Specifically, this is reflected in the following two points: 1. Catalyst Optimization: This invention employs a modified molecular sieve catalyst supported on platinum-cobalt bimetallic nanoparticles, promoting controllable Si-Si bond coupling through acidic sites and metal synergy. The catalyst surface is coated with thermosensitive polymeric gel microspheres, with a phase transition temperature of 25-35℃, dynamically regulating reaction activity and inhibiting over-polymerization. The thermosensitive polymeric gel microsphere coating also suppresses localized overheating and reduces butyrylane decomposition.

[0018] 2. Optimization of reaction conditions: Reaction temperature 150-220℃, pressure 0.3-0.8 MPa, to avoid decomposition of butyrylane due to high temperature. The volume ratio of silane to hydrogen is 80-90:10-20, with hydrogen acting as a carrier gas and chain terminator to regulate product chain length. Gas hourly space velocity 600-800 h⁻¹. -1 This ensures a balance between contact time and selectivity. Detailed Implementation

[0019] Catalyst Preparation Example 1 HZSM-5 molecular sieve (silicon-to-aluminum ratio 1200) was impregnated in a chloroplatinic acid / cobalt nitrate solution for 15 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.08 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:1. After removal, it was calcined at 530℃ in air for 4.5 hours to obtain 0.8 wt% molecular sieve-supported platinum-cobalt bimetallic nanoparticles. Thermosensitive polymeric gel microspheres were added into the pores of platinum-cobalt bimetallic nanoparticles supported by molecular sieves. The coating mass of the thermosensitive polymeric gel microspheres was 0.3% of the mass of the platinum-cobalt bimetallic nanoparticles supported by molecular sieves, as detailed below: Preparation of soaking solution: Thermosensitive polymeric gel microspheres are dispersed in anhydrous ethanol to prepare a dispersion with a mass concentration of 2.5%. Thermosensitive polymeric gel microspheres are poly-N-isopropylacrylamide gel microspheres. Equal volume impregnation: The dispersion was added dropwise to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve while stirring, and allowed to stand for adsorption at room temperature (28℃) for 6 hours; the mass ratio of the dispersion to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve was 4:6, and the addition time was 5 hours. Drying and curing: Drying at 60℃ under a nitrogen atmosphere for 15 hours to solidify the temperature-sensitive polymer gel microspheres and anchor them on the pore surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

[0020] Catalyst Preparation Example 2 X-type molecular sieves (silicon-to-aluminum ratio 1000) were immersed in a chloroplatinic acid / cobalt nitrate solution for 10 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.05 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:1. After calcination, 0.5 wt% molecular sieve-supported platinum-cobalt bimetallic nanoparticles were obtained. Thermosensitive polymeric gel microspheres were added into the pores of platinum-cobalt bimetallic nanoparticles supported by molecular sieves. The coating mass of the thermosensitive polymeric gel microspheres was 0.2% of the mass of the platinum-cobalt bimetallic nanoparticles supported by molecular sieves, as detailed below: Preparation of soaking solution: Thermosensitive polymeric gel microspheres are dispersed in anhydrous ethanol to prepare a dispersion with a mass concentration of 2%. Thermosensitive polymeric gel microspheres are poly-N-isopropylacrylamide gel microspheres. Equal volume impregnation: The dispersion was added dropwise to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve while stirring, and allowed to stand at room temperature (26℃) for 5 hours for adsorption; the mass ratio of the dispersion to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve was 3:7, and the addition time was 8 hours. Drying and curing: Drying at 60℃ under a nitrogen atmosphere for 18 hours to solidify the temperature-sensitive polymer gel microspheres and anchor them on the pore surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

[0021] Catalyst Preparation Example 3 Y-type molecular sieves (silicon-to-aluminum ratio 1500) were immersed in a chloroplatinic acid / cobalt nitrate solution for 18 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.1 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:1. After calcination, 1.5 wt% molecular sieve-supported platinum-cobalt bimetallic nanoparticles were obtained. Thermosensitive polymeric gel microspheres were added into the pores of platinum-cobalt bimetallic nanoparticles supported by molecular sieves. The coating mass of the thermosensitive polymeric gel microspheres was 0.4% of the mass of the platinum-cobalt bimetallic nanoparticles supported by molecular sieves, as detailed below: Preparation of soaking solution: Thermosensitive polymeric gel microspheres are dispersed in anhydrous ethanol to prepare a dispersion with a mass concentration of 3%. Thermosensitive polymeric gel microspheres are poly-N-isopropylacrylamide gel microspheres. Equal volume impregnation: The dispersion was added dropwise to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve while stirring, and allowed to stand at room temperature (25°C) for 4 hours for adsorption; the mass ratio of the dispersion to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve was 1:1, and the addition time was 4 hours. Drying and curing: Drying at 60℃ under a nitrogen atmosphere for 12 hours to solidify the temperature-sensitive polymer gel microspheres and anchor them on the pore surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

[0022] Catalyst Comparative Example 1 HZSM-5 molecular sieve (silicon-to-aluminum ratio 1200) was impregnated in a chloroplatinic acid / cobalt nitrate solution for 15 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.08 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:1. After removal, it was calcined at 530℃ in air for 4.5 hours to obtain 0.8 wt% molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

[0023] Example 1

[0024] Silane and hydrogen were mixed at a volume ratio of 85:15 and introduced into a fixed-bed reactor at a pressure of 0.5 MPa. The reaction temperature was 180 °C and the space velocity was 700 h⁻¹. -1 Catalyst Preparation Example 1: The catalyst prepared using HZSM-5 molecular sieve with a silicon-to-aluminum ratio of 1200, supported with 0.8 wt% platinum-cobalt bimetallic nanoparticles (platinum to cobalt molar ratio 1:1), and coated with thermosensitive polymer gel microspheres (phase transition temperature 30℃).

[0025] Results: The conversion rate of silane was 12%, the selectivity of propane was 75%, the selectivity of butane was 25%, and the mass content of by-product (polysilane) was 0.3%. This example represents the optimal reaction conditions, with the best synergistic effect between catalyst activity and selectivity, and the formation of by-products was effectively suppressed.

[0026] Example 2

[0027] Silane and hydrogen were mixed at a volume ratio of 80:20 and introduced into a fixed-bed reactor at a pressure of 0.3 MPa. The reaction temperature was 150 °C and the space velocity was 600 h⁻¹. -1 Catalyst Preparation Example 2: The catalyst prepared using HZSM-5 molecular sieve with a silicon-to-aluminum ratio of 1000, supported with 0.5 wt% platinum-cobalt bimetallic nanoparticles (platinum to cobalt mass ratio 1:1), and coated with thermosensitive polymer gel microspheres (phase transition temperature 25℃).

[0028] Results: The conversion rate of ethyl silane was 10%, the selectivity of propane was 75%, the selectivity of butane was 24%, and the mass content of by-product (polysilane) was 1.0%.

[0029] Example 3

[0030] Silane and hydrogen were mixed at a volume ratio of 90:10 and introduced into a fixed-bed reactor at a pressure of 0.8 MPa. The reaction temperature was 220 °C and the space velocity was 800 h⁻¹. -1 Catalyst Preparation Example 3: The catalyst prepared using HZSM-5 molecular sieve with a silicon-to-aluminum ratio of 1500, supported with 1.5 wt% platinum-cobalt bimetallic nanoparticles (platinum to cobalt molar ratio 2:1), and coated with thermosensitive polymer gel microspheres (phase transition temperature 35℃).

[0031] Results: The conversion rate of ethyl silane was 15%, the selectivity of propane was 74%, the selectivity of butane was 25%, and the mass content of by-product (polysilane) was 1.5%.

[0032] The silane, propane, and butane generated in Examples 1-3 were separated by distillation. The distillation column separated the products: propane with a boiling point of 52.9°C and butane with a boiling point of 108.1°C, and recovered by gradient condensation.

[0033] Comparative Example 1 The difference between this comparative example and Example 1 is that the catalyst added is the catalyst prepared in Comparative Example 1, and it is not coated with thermosensitive polymeric gel microspheres.

[0034] Results: The conversion rate of ethyl silane was 13%, the selectivity of propane was 68%, the selectivity of butane was 21%, and the mass content of by-product (polysilane) was 11%.

[0035] Comparative Example 2 The difference between this comparative example and Example 1 is that no catalyst is added.

[0036] Results: The conversion rate of silane was <1%, the selectivity of propane was 0, the selectivity of butane was 0, and the mass content of by-product (polysilane) was 0.

[0037] Comparative Example 3 The difference between this comparative example and Example 1 is that silane and hydrogen are mixed at a volume ratio of 50:50.

[0038] Results: The conversion rate of ethyl silane was 8%, the selectivity of propane was 62%, the selectivity of butane was 18%, and the mass content of by-products (polysilanes) was 20%.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for producing trisilane and tetrasilane from disilane, characterized by, Includes the following steps: Silane and hydrogen are introduced into a fixed-bed reactor at a pressure of 0.3-0.8 MPa for a catalytic reaction to produce propane and butane; The fixed bed reactor is loaded with catalyst; the catalytic reaction temperature is 150-220℃, the space velocity of ethylsilane and hydrogen is 600-800h -1 .

2. The method of claim 1, wherein the ethylsilane generates propylsilane and butylsilane. The volume ratio of silane to hydrogen is 80-90:10-20.

3. The method of claim 1, wherein the ethylsilane is produced by the reaction of propylsilane and butylsilane. The catalyst is a molecular sieve-supported platinum-cobalt bimetallic nanoparticle.

4. The method of claim 3, wherein the ethylsilane is produced by the reaction of propylsilane and butylsilane. The molecular sieve support has a SiO2 / Al2O3 molar ratio of 1000-1500 and is loaded with 0.5-1.5 wt% platinum-cobalt bimetallic nanoparticles, with a platinum to cobalt molar ratio of 1-2:

1.

5. The method for generating propane and butane from ethylsilane according to claim 3, characterized in that, The surface of platinum-cobalt bimetallic nanoparticles supported by molecular sieves is coated with thermosensitive polymer gel microspheres. The mass of the thermosensitive polymer gel microspheres is 0.2-0.4% of the mass of the platinum-cobalt bimetallic nanoparticles supported by molecular sieves, and the phase transition temperature is 25-35℃.

6. The method of claim 5, wherein the ethylsilane is produced in the presence of a catalyst. The thermosensitive polymeric gel microspheres are poly(N-isopropylacrylamide) gel microspheres, and the molecular sieve is HZSM, type A, type X, or type Y molecular sieve.

7. A method of ethylsilane production of propylsilane and butylsilane according to claim 5 or 6, characterized in that, The catalyst preparation method includes the following steps: Molecular sieves were immersed in a chloroplatinic acid / cobalt nitrate solution for 10-18 hours. The concentration of the chloroplatinic acid / cobalt nitrate solution was 0.05-0.1 mol / L, and the molar ratio of chloroplatinic acid to cobalt nitrate in the chloroplatinic acid / cobalt nitrate solution was 1:

1. After immersion, the sieves were calcined at 500-550℃ in air for 4-5 hours to obtain zeolite-cobalt bimetallic nanoparticles supported on the molecular sieves. Thermosensitive polymeric gel microspheres were added into the pores of platinum-cobalt bimetallic nanoparticles supported on molecular sieves.

8. The method of claim 7, wherein the ethylsilane is produced in the presence of a catalyst. The specific method for adding thermosensitive polymeric gel microspheres to the pores of platinum-cobalt bimetallic nanoparticles supported on molecular sieves includes the following steps: Preparation of soaking solution: Disperse thermosensitive polymeric gel microspheres in anhydrous ethanol to prepare a dispersion with a mass concentration of 2-3%; Equal volume impregnation: The dispersion is added dropwise to the platinum-cobalt bimetallic nanoparticles supported on the molecular sieve while stirring, and allowed to stand at room temperature for 4-6 hours for adsorption. Drying and curing: Drying at 60℃ under a nitrogen atmosphere for 12-18 hours to solidify the temperature-sensitive polymer gel microspheres and anchor them on the pore surface of the molecular sieve-supported platinum-cobalt bimetallic nanoparticles.

9. The method of claim 8, wherein the ethylsilane is produced in the presence of a catalyst. The mass ratio of the dispersion to the molecular sieve-supported platinum-cobalt bimetallic nanoparticles was 3-5:5-7, and the dropping time was 4-8 hours.

10. The method of claim 1, wherein the ethylsilane produces propylsilane and butylsilane. The selectivity of the butyrylane is not less than 24%.