Catalyst for conversion of methylchlorosilane high-boiling-point substances and preparation method and regeneration method thereof

Abstract

The invention discloses a catalyst for conversion of methyl chlorosilane high-boiling-point substances and a preparation method and a regeneration method thereof. The catalyst comprises a carrier and active components loaded on the carrier, the carrier is a carbon molecular sieve, the active components are metal halides, and the number of the metal chlorides is at least two. After trichlorosilane is subjected to catalytic carbon removal through the prepared catalyst, the catalytic conversion rate of methyl dichlorosilane in trichlorosilane is larger than or equal to 90%, and after the catalyst is regenerated through chlorine source gas and recycled for 10 times, the catalytic conversion rate of methyl dichlorosilane in trichlorosilane is larger than or equal to 86%. The method has the advantages that the operation process of catalyst preparation is simple, the catalytic efficiency is high, the regenerated catalyst can be recycled, and the cost in the production process is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of polysilicon production, and specifically relates to a catalyst for converting high-boiling-point substances of methylchlorosilane, and a preparation method and a regeneration method thereof. Background Art

[0002] With the continuous advancement of photovoltaic power generation technology, the conversion rate of solar cells is increasingly required, and at the same time, higher quality requirements are placed on polycrystalline silicon, the raw material of silicon-based solar cells. Studies have shown that carbon impurities are distributed in silicon crystals in the form of substitutional carbon or solid solution, affecting the periodic arrangement of the silicon atom lattice and the crystallization rate of single crystals, reducing the minority carrier lifetime and photoelectric conversion efficiency of silicon-based solar cells. Therefore, minimizing carbon impurities is crucial to the development of high-quality solar cells.

[0003] At present, the mainstream process for polysilicon production is still the modified Siemens technology. The specific route is: hydrogen chloride first reacts with metallic silicon to prepare crude trichlorosilane, and then the trichlorosilane is purified through multiple distillation and separation processes. After obtaining refined trichlorosilane, high-purity hydrogen reduction-vapor deposition is used to prepare high-purity silicon. During the reaction process, the carbon impurities in the silicon powder will react with chlorosilane to generate impurities such as methylchlorosilane, resulting in a high content of methylchlorosilane carbon-containing impurities in trichlorosilane, which in turn affects the quality of the terminal product polysilicon. Therefore, effectively removing methylchlorosilane impurities in trichlorosilane production is a key common problem that needs to be solved in polysilicon production. Since the boiling points of methyldichlorosilane and trichlorosilane are similar, the separation using distillation technology is difficult and energy-intensive, and needs to be converted into high-boiling-point methyltrichlorosilane. Among them, efficient catalysts are the key to achieving high-boiling-point conversion of methyldichlorosilane. Currently, the industry mostly uses tertiary amine-based macroporous cross-linked resins as catalysts to achieve the catalytic conversion of monomethyldichlorosilane in trichlorosilane. However, during the catalytic conversion of monomethyldichlorosilane, trichlorosilane is prone to disproportionation reaction, which increases the cost of polysilicon preparation. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a catalyst for the conversion of high-boiling-point methylchlorosilane and a preparation method and a regeneration method thereof in view of the above-mentioned deficiencies in the prior art, so as to improve the catalytic conversion efficiency of methyldichlorosilane in trichlorosilane and improve the distillation separation efficiency.

[0005] The technical solution adopted to solve the technical problem of the present invention is to provide a catalyst for the conversion of high-boiling-point methylchlorosilane, comprising: a carrier, an active component loaded on the carrier, the carrier is a carbon molecular sieve, the active component is a metal halide, and the metal chloride is at least two kinds. The carbon molecular sieve is a modified carbon molecular sieve.

[0006] Preferably, the metal element of the metal chloride is at least two of Li, Na, K, Mg, Ce, Zn, Ca, Fe, Al, Ni, Ti, Cu, and Sn, and the halogen of the metal chloride is at least one of F, Cl, Br, and I.

[0007] Preferably, the porosity of the catalyst carrier carbon molecular sieve is 5 to 40%, and the active component loading is 1 to 30 wt%.

[0008] The present invention also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0009] 1) hot extrusion molding of the matrix carbon molecular sieve;

[0010] 2) Carry out pore expansion modification on the carbon molecular sieve;

[0011] 3) performing oxidation modification on the carbon molecular sieve after pore expansion modification;

[0012] 4) regulating the pore size of the oxidatively modified carbon molecular sieve to obtain a carrier carbon molecular sieve;

[0013] 5) The active component is loaded on a carrier carbon molecular sieve, wherein the active component is a metal halide and the metal chlorides are at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances.

[0014] Preferably, the step 1) of extruding the carbon molecular sieve comprises:

[0015] The matrix raw material is mixed and stirred with asphalt, and then hot extruded to obtain the catalyst matrix carbon molecular sieve.

[0016] Preferably, the catalyst substrate in step 1) is cylindrical or spherical, with an equivalent diameter of 1.0 to 5.0 mm;

[0017] The particle size of the matrix material is 0.03mm~0.50mm

[0018] The temperature of hot extrusion molding is 500-700°C.

[0019] Preferably, the matrix material in step 1) is any one of fine-porous activated carbon, macroporous resin, and petroleum coke;

[0020] The mass ratio of asphalt to base material is 1:(5-30).

[0021] Preferably, the step 2) of performing pore expansion modification on the carbon molecular sieve is specifically as follows:

[0022] The carbon molecular sieve matrix is ​​burned in a nitrogen atmosphere at a temperature of 300 to 1200° C. for a time of 0.5 to 6 hours.

[0023] Preferably, the step 3) of oxidatively modifying the carbon molecular sieve after pore expansion modification is specifically as follows:

[0024] The carbon molecular sieve after pore expansion modification is oxidized by using an oxidant, wherein the oxidant is a nitric acid solution and / or a perchloric acid solution.

[0025] Preferably, the step 4) controls the pore size of the oxidatively modified carbon molecular sieve to obtain the carrier carbon molecular sieve as follows:

[0026] The oxidatively modified carbon molecular sieve is impregnated with a saturated aqueous solution of a first metal halide and then dried to obtain a carrier carbon molecular sieve.

[0027] Preferably, in the step 4), the metal element of the first metal halide is any one or more of Li, Na, K, Mg, and Ca.

[0028] Preferably, the immersion temperature in step 4) is 30-85°C, and the immersion time is 30-240 min;

[0029] The drying temperature is 100-150°C, and the drying time is 30-240 minutes.

[0030] Preferably, in step 5), the active component is loaded on the carbon molecular sieve, wherein the active component is a metal halide, and the metal chloride is at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances, specifically:

[0031] A saturated solution of a second metal halide is prepared with an organic solvent as the solvent, the carrier carbon molecular sieve is impregnated, and then dried. The organic solvent is one or a mixture of methanol, ethanol, ether, cyclohexane, and acetone. The metal element of the second metal halide is at least one of Ce, Zn, Fe, Al, Cu, Ti, Ni, and Sn.

[0032] Preferably, the immersion time in step 5) is 60 to 480 minutes, and the immersion temperature is 0 to 50° C.;

[0033] The drying temperature is 30-150°C, and the drying time is 30-240 minutes.

[0034] The present invention also provides a method for regenerating the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, which comprises the following steps after the catalyst fails:

[0035] The spent catalyst is regenerated online using chlorine source gas.

[0036] Preferably, the chlorine source gas is at least one of chlorine, hydrogen chloride, trichlorosilane and silicon tetrachloride.

[0037] Preferably, the regeneration temperature ranges from 0 to 80° C. and the regeneration time ranges from 1 to 12 hours during the chlorine source gas treatment.

[0038] Compared with the reported high-boiling-point conversion catalyst of methylchlorosilane, the invention discloses a catalyst for the conversion of high-boiling-point substances of methylchlorosilane and a preparation method and a regeneration method thereof, which have the following advantages: compared with conventional activated carbon, silica gel and activated alumina carriers, the carbon molecular sieve carrier subjected to extrusion molding / calcination pore expansion modification / pore size control has uniform pore size distribution and strong wear resistance, which is conducive to the selective adsorption and catalytic conversion of monomethylchlorosilane; after oxidation modification, the carbon molecular sieve has a large number of hydroxyl groups, carboxyl groups, lactones and other oxygen-containing and nitrogen-containing functional groups on the inner surface, which is conducive to the subsequent pore size control of metal chloride loading and improves the bonding strength between the active component and the matrix; a non-aqueous organic reagent is used as a solvent to prepare a saturated metal halide solution, and the carbon molecular sieve is impregnated, which can effectively inhibit the hydrolysis of the active component metal chloride during the impregnation and drying processes, thereby effectively maintaining the activity of the catalyst, and the synergistic effect of the oxygen (nitrogen) functional groups on the surface of the carbon molecular sieve and the multi-component metal halide effectively increases the number of active sites on the catalyst surface, thereby achieving the effect of improving the catalytic effect.

[0039] After the catalyst prepared by the invention catalytically removes carbon from trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled for 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥86%.

[0041] The advantages of the present invention are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0043] Example 1

[0044] This embodiment provides a catalyst for converting high-boiling-point methylchlorosilane, comprising: a carrier, an active component supported on the carrier, the carrier being a carbon molecular sieve, the active component being a metal halide, and the metal chloride being at least two kinds. The carbon molecular sieve is a modified carbon molecular sieve.

[0045] This embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0046] 1) hot extrusion molding of the matrix carbon molecular sieve;

[0047] 2) Carry out pore expansion modification on the carbon molecular sieve;

[0048] 3) performing oxidation modification on the carbon molecular sieve after pore expansion modification;

[0049] 4) regulating the pore size of the oxidatively modified carbon molecular sieve to obtain a carrier carbon molecular sieve;

[0050] 5) The active component is loaded on a carrier carbon molecular sieve, wherein the active component is a metal halide and the metal chlorides are at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances.

[0051] This embodiment also provides a method for regenerating the catalyst for converting high-boiling-point methylchlorosilane. After the catalyst fails, the method comprises the following steps:

[0052] The spent catalyst is regenerated online using chlorine source gas.

[0053] After the catalyst prepared in this embodiment catalyzes the decarbonization of trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled for 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥86%.

[0054] The advantages of this embodiment are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process.

[0055] Example 2

[0056] This embodiment provides a catalyst for converting high-boiling-point methylchlorosilane, comprising: a carrier, an active component supported on the carrier, the carrier being a carbon molecular sieve, the active component being a metal halide, and the metal chloride being at least two kinds. The carbon molecular sieve is a modified carbon molecular sieve.

[0057] Preferably, the metal element of the metal chloride is at least two of Li, Na, K, Mg, Ce, Zn, Ca, Fe, Al, Ni, Ti, Cu, and Sn, and the halogen of the metal chloride is at least one of F, Cl, Br, and I.

[0058] Preferably, the porosity of the catalyst carrier carbon molecular sieve is 5 to 40%, and the active component loading is 1 to 30 wt%.

[0059] This embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0060] 1) hot extrusion molding of the matrix carbon molecular sieve;

[0061] 2) Carry out pore expansion modification on the carbon molecular sieve;

[0062] 3) performing oxidation modification on the carbon molecular sieve after pore expansion modification;

[0063] 4) regulating the pore size of the oxidatively modified carbon molecular sieve to obtain a carrier carbon molecular sieve;

[0064] 5) The active component is loaded on a carrier carbon molecular sieve, wherein the active component is a metal halide and the metal chlorides are at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances.

[0065] Preferably, the step 1) of hot extrusion molding the carbon molecular sieve is specifically as follows:

[0066] The matrix raw material is mixed and stirred with asphalt, and then hot extruded to obtain a catalyst matrix carbon molecular sieve, and the extrusion molding temperature is 500-700°C.

[0067] Preferably, the catalyst substrate in step 1) is cylindrical or spherical, with an equivalent diameter of 1.0 to 5.0 mm;

[0068] The particle size of the matrix raw material is 0.03 mm to 0.50 mm.

[0069] Preferably, the matrix material in step 1) is any one of fine-porous activated carbon, macroporous resin, and petroleum coke;

[0070] The mass ratio of asphalt to base material is 1:(5-30).

[0071] Preferably, the step 2) of performing pore expansion modification on the carbon molecular sieve is specifically as follows:

[0072] The carbon molecular sieve matrix is ​​burned in a nitrogen atmosphere at a temperature of 300 to 1200° C. for a time of 0.5 to 6 hours.

[0073] Preferably, the step 3) of oxidatively modifying the carbon molecular sieve after pore expansion modification is specifically as follows:

[0074] The carbon molecular sieve after pore expansion modification is oxidized by using an oxidant, wherein the oxidant is a nitric acid solution and / or a perchloric acid solution.

[0075] Preferably, the step 4) controls the pore size of the oxidatively modified carbon molecular sieve to obtain the carrier carbon molecular sieve as follows:

[0076] The oxidatively modified carbon molecular sieve is impregnated with a saturated aqueous solution of a first metal halide and then dried to obtain a carrier carbon molecular sieve.

[0077] Preferably, in the step 4), the metal element of the first metal halide is any one or more of Li, Na, K, Mg, and Ca.

[0078] Preferably, the immersion temperature in step 4) is 30-85°C, and the immersion time is 30-240 min;

[0079] The drying temperature is 100-150°C, and the drying time is 30-240 minutes.

[0080] Preferably, in step 5), the active component is loaded on the carbon molecular sieve, wherein the active component is a metal halide, and the metal chloride is at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances, specifically:

[0081] A saturated solution of a second metal halide is prepared with an organic solvent as the solvent, the carrier carbon molecular sieve is impregnated, and then dried. The organic solvent is one or a mixture of methanol, ethanol, ether, cyclohexane, and acetone. The metal element of the second metal halide is at least one of Ce, Zn, Fe, Al, Cu, Ti, Ni, and Sn.

[0082] Preferably, the immersion time in step 5) is 60 to 480 minutes, and the immersion temperature is 0 to 50° C.;

[0083] The drying temperature is 30-150°C, and the drying time is 30-240 minutes.

[0084] This embodiment also provides a method for regenerating the catalyst for converting high-boiling-point methylchlorosilane. After the catalyst fails, the method comprises the following steps:

[0085] The spent catalyst is regenerated online using chlorine source gas.

[0086] Preferably, the chlorine source gas is at least one of chlorine, hydrogen chloride, trichlorosilane and silicon tetrachloride.

[0087] Preferably, the regeneration temperature ranges from 0 to 80° C. and the regeneration time ranges from 1 to 12 hours during the chlorine source gas treatment.

[0088] Specifically, this embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0089] 1) The fine-pored activated carbon matrix raw material and asphalt are mixed and stirred, and then hot-extruded at a temperature of 600°C to obtain a catalyst matrix. The matrix shape is cylindrical, with a diameter of 1.5 to 1.6 mm and a height of 1.5 to 2.5 mm. The matrix raw material is fine-pored activated carbon with a particle size of 0.035 to 0.075 mm. The ratio of asphalt to matrix raw material is 1:9.

[0090] 2) The catalyst substrate was burned in a nitrogen atmosphere at a temperature of 630-650° C. for 120 min.

[0091] 3) The carbon molecular sieve was impregnated and modified with a 3M nitric acid solution for 120 min at a temperature of 30-35° C. After oxidation modification, the porosity of the carbon molecular support was 19.3%.

[0092] 4) preparing a saturated sodium chloride solution, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 125° C., respectively, and the time is 120 min.

[0093] 5) Using ether as solvent, a saturated solution of aluminum chloride / ether was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a two-component catalyst with an active component loading of 12.6%.

[0094] The catalyst was used to perform a catalytic carbon removal reaction, and the conversion rate of trichlorosilane to monomethyldichlorosilane was measured to be 92.7%. After the conversion rate of monomethyldichlorosilane began to decrease, the chlorine flow rate was 5 cm 3 / min, regeneration temperature of 25°C, and regeneration time of 2h, the used catalyst was regenerated with chlorine. After five cycles of use, the conversion rate of methyldichlorosilane was 88.3%.

[0095] Compared with the reported high-boiling-point conversion catalyst of methylchlorosilane, the present embodiment discloses a catalyst for the conversion of high-boiling-point substances of methylchlorosilane and its preparation method and regeneration method, and the advantages are: compared with conventional activated carbon, silica gel, and activated alumina carriers, the carbon molecular sieve carrier after extrusion molding / calcination pore expansion modification / pore size control has a uniform pore size distribution and strong wear resistance, which is conducive to the selective adsorption and catalytic conversion of monomethylchlorosilane; after oxidation modification, the number of hydroxyl groups, carboxyl groups, lactones and other oxygen-containing and nitrogen-containing functional groups on the inner surface of the carbon molecular sieve is large, which is conducive to the subsequent pore size control of metal chloride loading and improves the bonding strength between the active component and the matrix; using a non-aqueous organic reagent as a solvent, preparing a saturated solution of a metal halide, and impregnating the carbon molecular sieve can effectively inhibit the hydrolysis of the active component metal chloride during the impregnation and drying process, thereby effectively maintaining the activity of the device, and the synergistic effect of the oxygen (nitrogen) functional groups on the surface of the carbon molecular sieve and the multi-component metal halide effectively increases the number of active sites on the catalyst surface, thereby achieving the effect of improving the catalytic effect.

[0096] After the catalyst prepared in this embodiment catalyzes the decarbonization of trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled for 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥86%.

[0097] The advantages of this embodiment are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process.

[0098] Example 3

[0099] This embodiment also provides a preparation method of the above-mentioned catalyst for the conversion of high-boiling-point methylchlorosilane, which is different from the preparation method in Example 2 in that it includes the following steps:

[0100] 1) The fine-pored activated carbon matrix raw material and asphalt are mixed and stirred, and then hot-extruded at a temperature of 500° C. to obtain a catalyst matrix. The matrix shape is cylindrical, with a diameter of 1.5 to 1.6 mm and a height of 1.5 to 2.5 mm. The matrix raw material is fine-pored activated carbon with a particle size of 0.035 to 0.075 mm. The ratio of asphalt to matrix raw material is 1:8.

[0101] 2) The catalyst substrate was burned in a nitrogen atmosphere at a temperature of 730-750° C. for 120 min.

[0102] 3) The carbon molecular sieve was impregnated and modified with a 3M nitric acid solution for 120 min at a temperature of 30-35° C. During the modification process, ultrasonic dispersion was performed. After oxidation modification, the porosity of the carbon molecular carrier was 22.4%.

[0103] 4) preparing a saturated sodium chloride solution, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 125° C., respectively, and the time is 120 min.

[0104] 5) Using ether as solvent, a saturated solution of aluminum chloride / ether was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a two-component catalyst with an active component loading of 15.3%.

[0105] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of monomethyldichlorosilane in trichlorosilane was measured to be 93.8%.

[0106] Example 4

[0107] This embodiment also provides a preparation method of the above-mentioned catalyst for the conversion of high-boiling-point methylchlorosilane, which is different from the preparation method in Example 2 in that it includes the following steps:

[0108] The modified carbon molecular sieve prepared in Example 3 was used as a carrier.

[0109] 4) preparing a saturated magnesium chloride solution, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 125° C., respectively, and the time is 120 min.

[0110] 5) Using ethanol as solvent, a titanium tetrachloride / ethanol saturated solution was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a two-component catalyst with an active component loading of 15.7%.

[0111] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of methyldichlorosilane was 95.4%.

[0112] Example 5

[0113] This embodiment also provides a preparation method of the above-mentioned catalyst for the conversion of high-boiling-point methylchlorosilane, which is different from the preparation method in Example 2 in that it includes the following steps:

[0114] The modified carbon molecular sieve prepared in Example 3 was used as a carrier.

[0115] 4) preparing a mixed saturated solution of sodium chloride and magnesium chloride, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 125° C., respectively, and the time is 120 min.

[0116] 5) Using ethanol as solvent, titanium tetrachloride and aluminum chloride / ethanol mixed saturated solution were prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a two-component catalyst with an active component loading of 15.4%.

[0117] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of methyldichlorosilane was 95.4%.

[0118] Example 6

[0119] This embodiment also provides a preparation method of the above-mentioned catalyst for the conversion of high-boiling-point methylchlorosilane, which is different from the preparation method in Example 2 in that it includes the following steps:

[0120] 1) Mix and stir the petroleum coke matrix raw material and asphalt, and then hot extrude them at a temperature of 700° C. to obtain a catalyst matrix. The matrix is ​​cylindrical in shape with a diameter of 1.5 to 1.6 mm and a height of 1.5 to 2.5 mm. The matrix raw material is petroleum coke with a particle size of 0.038 to 0.050 mm. The ratio of asphalt to matrix raw material is 1:8.

[0121] 2) The catalyst substrate was burned in a nitrogen atmosphere at a temperature of 730-750° C. for 120 min.

[0122] 3) The carbon molecular sieve was impregnated and modified with a 3M nitric acid solution for 120 min at a temperature of 30-35° C. During the modification process, ultrasonic dispersion was performed. After oxidation modification, the porosity of the carbon molecular carrier was 17.6%.

[0123] 4) preparing a mixed saturated solution of sodium chloride and magnesium chloride, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 125° C., respectively, and the time is 120 min.

[0124] 5) Using ethanol as solvent, titanium tetrachloride and aluminum chloride / ethanol mixed saturated solution were prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a multi-component catalyst with an active component loading of 13.9%.

[0125] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of methyldichlorosilane was 91.5%.

[0126] Comparative Example 1

[0127] The carbon molecular sieve was prepared by the method described in Example 5, without oxidative modification of the carbon molecular sieve, and other modifications and metal chloride loading were the same as in Example 5. The loading amount of the active component of the prepared catalyst was 12.1%, and the conversion rate of methyldichlorosilane was 81.9% when the catalyst was used for catalytic carbon removal reaction.

[0128] Comparative Example 2

[0129] The modified carbon molecular sieve was prepared by the method described in Example 5, using ethanol as solvent, preparing a saturated solution of titanium tetrachloride and aluminum chloride / ethanol mixture, further impregnating and modifying the carbon molecular sieve, and then drying, the impregnation and drying temperatures were 25° C. and 50° C., respectively, and the time was 90 min to obtain a two-component catalyst with an active component loading of 10.9%. The catalyst was used to carry out a catalytic decarbonization reaction, and the conversion rate of methyldichlorosilane was 71.9%.

[0130] Comparative Example 3

[0131] The modified carbon molecular sieve was prepared by the method described in Example 5, and a mixed saturated solution of sodium chloride and magnesium chloride was prepared, and the oxidized modified carbon molecular sieve was impregnated and then dried. The impregnation and drying temperatures were 30° C. and 125° C., respectively, and the time was 120 min to obtain a two-component catalyst with an active component loading of 7.9%. The catalyst was used to carry out a catalytic carbon removal reaction, and the conversion rate of methyldichlorosilane was 34.7%.

[0132] Example 7

[0133] This embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0134] 1) Mix and stir the macroporous resin matrix raw material and asphalt, and then hot extrude them at a temperature of 500°C to obtain a catalyst matrix. The matrix is ​​cylindrical in shape with a diameter of 2.5 to 2.6 mm and a height of 1.5 to 2.5 mm. The matrix raw material is fine-porous activated carbon with a particle size of 0.030 to 0.060 mm. The ratio of asphalt to matrix raw material is 1:5.

[0135] 2) The catalyst substrate is burned in a nitrogen atmosphere at a temperature of 300-400°C for 0.5 h.

[0136] 3) The carbon molecular sieve was impregnated and modified with a 3M perchloric acid solution for 120 min at a temperature of 30-35° C. After oxidation modification, the porosity of the carbon molecular carrier was 5%.

[0137] 4) preparing a saturated lithium iodide solution, impregnating the oxidatively modified molecular sieve, and then drying, the impregnation and drying temperatures are 30° C. and 100° C., and the times are 30 min and 30 min, respectively.

[0138] 5) Using methanol and ethanol as solvents (mass ratio 1:1), a saturated solution of nickel chloride and tin chloride was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 0°C and 30°C, and the times were 200 min and 30 min, respectively, to obtain a two-component catalyst with an active component loading of 1%.

[0139] This embodiment provides a catalyst for converting high-boiling-point methylchlorosilane, which is prepared by the above method.

[0140] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of monomethyldichlorosilane in trichlorosilane was measured to be 93.2%.

[0141] After the conversion rate of monomethyldichlorosilane began to decrease, at a hydrogen chloride flow rate of 5 cm 3 / min, regeneration temperature of 40℃, and regeneration time of 1h, the used catalyst was regenerated with chlorine. After five cycles of use, the conversion rate of methyldichlorosilane was 87.1%.

[0142] Compared with the reported high-boiling-point conversion catalyst of methylchlorosilane, the present embodiment discloses a catalyst for the conversion of high-boiling-point substances of methylchlorosilane and its preparation method and regeneration method, and the advantages are: compared with conventional activated carbon, silica gel, and activated alumina carriers, the carbon molecular sieve carrier after extrusion molding / calcination pore expansion modification / pore size control has a uniform pore size distribution and strong wear resistance, which is conducive to the selective adsorption and catalytic conversion of monomethylchlorosilane; after oxidation modification, the number of hydroxyl groups, carboxyl groups, lactones and other oxygen-containing and nitrogen-containing functional groups on the inner surface of the carbon molecular sieve is large, which is conducive to the subsequent pore size control of metal chloride loading and improves the bonding strength between the active component and the matrix; using a non-aqueous organic reagent as a solvent, preparing a saturated solution of a metal halide, and impregnating the carbon molecular sieve can effectively inhibit the hydrolysis of the active component metal chloride during the impregnation and drying process, thereby effectively maintaining the activity of the device, and the synergistic effect of the oxygen (nitrogen) functional groups on the surface of the carbon molecular sieve and the multi-component metal halide effectively increases the number of active sites on the catalyst surface, thereby achieving the effect of improving the catalytic effect.

[0143] After the catalyst prepared in this embodiment catalyzes carbon removal on trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled for 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥85%.

[0144] The advantages of this embodiment are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process.

[0145] Example 8

[0146] This embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0147] 1) The petroleum coke matrix raw material and asphalt are mixed and stirred, and then hot extruded at a temperature of 550° C. to obtain a catalyst matrix. The matrix shape is cylindrical, with a diameter of 1.0 to 1.1 mm and a height of 1.5 to 2.5 mm. The matrix raw material is fine-porous activated carbon with a particle size of 0.30 to 0.40 mm. The ratio of asphalt to matrix raw material is 1:20.

[0148] 2) The catalyst substrate was burned in a nitrogen atmosphere at a temperature of 800-820°C for 3 hours.

[0149] 3) The carbon molecular sieve was impregnated and modified with a mixed solution of 3M nitric acid solution and perchloric acid solution (the mass ratio of nitric acid to perchloric acid was 1:1) for 120 min at a temperature of 30-35° C. After oxidation modification, the porosity of the carbon molecular support was 25%.

[0150] 4) A saturated potassium bromide solution was prepared, and the oxidatively modified molecular sieve was impregnated and then dried. The impregnation and drying temperatures were 50° C. and 130° C., and the times were 120 min and 120 min, respectively.

[0151] 5) Using cyclohexane as solvent, a saturated solution of zinc chloride and ferric chloride in cyclohexane was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 30° C. and 100° C., and the times were 60 min and 120 min, respectively, to obtain a two-component catalyst with an active component loading of 20%.

[0152] This embodiment provides a catalyst for converting high-boiling-point methylchlorosilane, which is prepared by the above method.

[0153] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of monomethyldichlorosilane in trichlorosilane was measured to be 92.5%.

[0154] After the conversion rate of monomethyldichlorosilane began to decrease, at a trichlorosilane flow rate of 5 cm 3 / min, regeneration temperature of 0°C, and regeneration time of 6h, the used catalyst was regenerated with chlorine. After five cycles of use, the conversion rate of methyldichlorosilane was 87.8%.

[0155] Compared with the reported high-boiling-point conversion catalyst of methylchlorosilane, the present embodiment discloses a catalyst for the conversion of high-boiling-point substances of methylchlorosilane and its preparation method and regeneration method, and the advantages are: compared with conventional activated carbon, silica gel, and activated alumina carriers, the carbon molecular sieve carrier after extrusion molding / calcination pore expansion modification / pore size control has a uniform pore size distribution and strong wear resistance, which is conducive to the selective adsorption and catalytic conversion of monomethylchlorosilane; after oxidation modification, the number of hydroxyl groups, carboxyl groups, lactones and other oxygen-containing and nitrogen-containing functional groups on the inner surface of the carbon molecular sieve is large, which is conducive to the subsequent pore size control of metal chloride loading and improves the bonding strength between the active component and the matrix; using a non-aqueous organic reagent as a solvent, preparing a saturated solution of a metal halide, and impregnating the carbon molecular sieve can effectively inhibit the hydrolysis of the active component metal chloride during the impregnation and drying process, thereby effectively maintaining the activity of the device, and the synergistic effect of the oxygen (nitrogen) functional groups on the surface of the carbon molecular sieve and the multi-component metal halide effectively increases the number of active sites on the catalyst surface, thereby achieving the effect of improving the catalytic effect.

[0156] After the catalyst prepared in this embodiment catalyzes carbon removal on trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled for 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥87%.

[0157] The advantages of this embodiment are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process.

[0158] Example 9

[0159] This embodiment also provides a method for preparing the above-mentioned catalyst for converting high-boiling-point methylchlorosilane, comprising the following steps:

[0160] 1) Mix and stir the macroporous resin raw material and asphalt, and then hot extrude them at a temperature of 650°C to obtain a catalyst matrix. The matrix is ​​cylindrical in shape with a diameter of 4.9-5.0 mm and a height of 1.5-2.5 mm. The matrix raw material is fine-porous activated carbon with a particle size of 0.4-0.5 mm. The ratio of asphalt to matrix raw material is 1:30.

[0161] 2) The catalyst substrate is burned in a nitrogen atmosphere at a temperature of 1180-1200°C for 6 hours.

[0162] 3) The carbon molecular sieve was impregnated and modified with a 3M nitric acid solution for 120 min at a temperature of 30-35° C. After oxidation modification, the porosity of the carbon molecular carrier was 40%.

[0163] 4) A saturated calcium fluoride solution was prepared, and the oxidatively modified molecular sieve was impregnated and then dried. The impregnation and drying temperatures were 85° C. and 150° C., and the times were 240 min and 240 min, respectively.

[0164] 5) Using acetone as solvent, a saturated acetone solution of cupric chloride and cerium chloride was prepared, and the carbon molecular sieve was further impregnated and modified, and then dried. The impregnation and drying temperatures were 50° C. and 150° C., and the times were 480 min and 240 min, respectively, to obtain a two-component catalyst with an active component loading of 30%.

[0165] This embodiment provides a catalyst for converting high-boiling-point methylchlorosilane, which is prepared by the above method.

[0166] The catalyst was used to carry out catalytic carbon removal reaction, and the conversion rate of monomethyldichlorosilane in trichlorosilane was measured to be 92.8%.

[0167] After the conversion rate of monomethyldichlorosilane began to decrease, at a flow rate of 5 cm 3 Under the conditions of 0.1% chlorine gas, 0.2% chlorine gas was used to regenerate the used catalyst under the conditions of 0.1% chlorine gas, 0.2% chlorine gas and 0.5% methyldichlorosilane conversion after five cycles of use.

[0168] Compared with the reported high-boiling-point conversion catalyst of methylchlorosilane, the present embodiment discloses a catalyst for the conversion of high-boiling-point substances of methylchlorosilane and its preparation method and regeneration method, and the advantages are: compared with conventional activated carbon, silica gel, and activated alumina carriers, the carbon molecular sieve carrier after extrusion molding / calcination pore expansion modification / pore size control has a uniform pore size distribution and strong wear resistance, which is conducive to the selective adsorption and catalytic conversion of monomethylchlorosilane; after oxidation modification, the number of hydroxyl groups, carboxyl groups, lactones and other oxygen-containing and nitrogen-containing functional groups on the inner surface of the carbon molecular sieve is large, which is conducive to the subsequent pore size control of metal chloride loading and improves the bonding strength between the active component and the matrix; using a non-aqueous organic reagent as a solvent, preparing a saturated solution of a metal halide, and impregnating the carbon molecular sieve can effectively inhibit the hydrolysis of the active component metal chloride during the impregnation and drying process, thereby effectively maintaining the activity of the device, and the synergistic effect of the oxygen (nitrogen) functional groups on the surface of the carbon molecular sieve and the multi-component metal halide effectively increases the number of active sites on the catalyst surface, thereby achieving the effect of improving the catalytic effect.

[0169] After the catalyst prepared in this embodiment catalyzes carbon removal on trichlorosilane, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥90%. After the catalyst is regenerated by chlorine source gas and recycled 10 times, the catalytic conversion rate of monomethyldichlorosilane in trichlorosilane is ≥82%.

[0170] The advantages of this embodiment are: the operation process of catalyst preparation is simple, the catalytic efficiency is high, and the regenerated catalyst can be recycled, thereby reducing the cost in the production process.

[0171] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A catalyst for the conversion of high-boiling-point substances of methylchlorosilane, characterized in that: include: The carrier and the active component loaded on the carrier are carbon molecular sieves, the active component is metal halides, and the metal chlorides are at least two kinds.

2. The catalyst for conversion of high boiling point methylchlorosilane according to claim 1, characterized in that: The metal element of the metal chloride is at least two of Li, Na, K, Mg, Ce, Zn, Ca, Fe, Al, Ni, Ti, Cu, and Sn, and the halogen of the metal chloride is at least one of F, Cl, Br, and I.

3. The catalyst for conversion of high boiling point methylchlorosilane according to claim 1, characterized in that: The porosity of the catalyst carrier carbon molecular sieve is 5-40%, and the active component loading amount is 1-30wt%.

4. The high boiling point methylchlorosilane according to any one of claims 1 to 3 The method for preparing a catalyst for material conversion is characterized in that: The following steps are involved: 1) hot extrusion molding of the matrix carbon molecular sieve; 2) Carry out pore expansion modification on the carbon molecular sieve; 3) performing oxidation modification on the carbon molecular sieve after pore expansion modification; 4) regulating the pore size of the oxidatively modified carbon molecular sieve to obtain a carrier carbon molecular sieve; 5) The active component is loaded on a carrier carbon molecular sieve, wherein the active component is a metal halide and the metal chlorides are at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances.

5. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 4, characterized in that: The step 1) of hot extrusion molding the carbon molecular sieve is specifically as follows: The matrix raw material is mixed and stirred with asphalt, and then hot extruded to obtain a catalyst matrix carbon molecular sieve, and the extrusion molding temperature is 500-700°C.

6. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 5, characterized in that: The catalyst substrate in step 1) is cylindrical or spherical, with an equivalent diameter of 1.0 to 5.0 mm; The particle size of the matrix raw material is 0.03 mm to 0.50 mm.

7. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 5, characterized in that: In the step 1), the matrix material is any one of fine-porous activated carbon, macroporous resin, and petroleum coke; The mass ratio of asphalt to base material is 1:(5-30).

8. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 4, characterized in that: The step 2) of performing pore expansion modification on the carbon molecular sieve is specifically as follows: The carbon molecular sieve matrix is ​​burned in a nitrogen atmosphere at a temperature of 300 to 1200° C. for a time of 0.5 to 6 hours.

9. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 4, characterized in that: The step 3) of oxidatively modifying the carbon molecular sieve after pore expansion modification is specifically as follows: The carbon molecular sieve after pore expansion modification is oxidized by using an oxidant, wherein the oxidant is a nitric acid solution and / or a perchloric acid solution.

10. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 4, characterized in that: The step 4) controls the pore size of the oxidatively modified carbon molecular sieve to obtain the carrier carbon molecular sieve as follows: The oxidatively modified carbon molecular sieve is impregnated with a saturated aqueous solution of a first metal halide and then dried to obtain a carrier carbon molecular sieve.

11. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 10, characterized in that: In the step 4), the metal element of the first metal halide is any one or more of Li, Na, K, Mg, and Ca.

12. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 10, characterized in that: The immersion temperature in step 4) is 30-85°C, and the immersion time is 30-240 minutes; The drying temperature is 100-150°C, and the drying time is 30-240 minutes.

13. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 4, characterized in that: The step 5) supports the active component on the carbon molecular sieve, wherein the active component is a metal halide and the metal chloride is at least two kinds, to obtain a catalyst for the conversion of methylchlorosilane high boiling point substances, specifically: A saturated solution of a second metal halide is prepared with an organic solvent as the solvent, the carrier carbon molecular sieve is impregnated, and then dried. The organic solvent is one or a mixture of methanol, ethanol, ether, cyclohexane, and acetone. The metal element of the second metal halide is at least one of Ce, Zn, Fe, Al, Cu, Ti, Ni, and Sn.

14. The method for preparing a catalyst for converting high-boiling-point methylchlorosilane according to claim 13, characterized in that: The immersion time in step 5) is 60 to 480 minutes, and the immersion temperature is 0 to 50° C.; The drying temperature is 30-150°C, and the drying time is 30-240 minutes.

15. A method for regenerating a catalyst for converting high-boiling-point methylchlorosilane according to any one of claims 1 to 3, wherein after the catalyst fails, the method comprises: The following steps are involved: The spent catalyst is regenerated online using chlorine source gas.

16. The method for regenerating a catalyst for converting high-boiling-point methylchlorosilane according to claim 15, characterized in that: The chlorine source gas is at least one of chlorine, hydrogen chloride, trichlorosilane and silicon tetrachloride.

17. The method for regenerating a catalyst for converting high-boiling-point methylchlorosilane according to claim 15, characterized in that: During chlorine source gas treatment, the regeneration temperature ranges from 0 to 80°C, and the regeneration time ranges from 1 to 12 hours.