Process for the preparation of dichlorosilane by disproportionation and molybdenum-based supported catalysts used

Abstract

The present application belongs to the field of chemical industry, and relates to preparation of hydrogen silicon and catalytic material, in particular to a method for preparing dichlorohydrogen silicon by disproportionation and a molybdenum-based supported catalyst used in the method. The method for preparing dichlorohydrogen silicon by disproportionation comprises the following steps: adding the molybdenum-based supported catalyst into a tubular fixed-bed reactor, activating at high temperature by passing hydrogen, then passing trichlorohydrogen silicon, controlling the reaction pressure to be 0.1-1.0 MPa, heating to the reaction temperature, and then reacting until the reaction system is stable, and collecting the product. The catalyst carrier used in the present application is cheap and easy to obtain, and can be directly dispersed in a reaction solution of molybdenum complex for impregnation without pretreatment, so the operation is simple. High-temperature calcination enhances the thermal stability of the catalyst, so that the dichlorohydrogen silicon can be prepared by disproportionation at a higher reaction temperature, and the yield of dichlorohydrogen silicon is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of chemical industry, and relates to the preparation of hydrogen silicide and catalytic materials, in particular to a method for preparing dichlorosilane through disproportionation and a molybdenum-based supported catalyst used in the method. BACKGROUND

[0002] In recent years, with the increasing energy crisis, the solar photovoltaic industry has developed rapidly worldwide, resulting in a sharp increase in demand for polycrystalline silicon, the main raw material for solar cells. In recent years, the preparation technology of polycrystalline silicon raw materials has become the main bottleneck restricting the development of the photovoltaic industry. Dichlorosilane is generally used as a silicon source gas in semiconductor epitaxy and chemical vapor deposition processes for the preparation of silane. If the conversion rate of trichlorosilane reaction to dichlorosilane can be improved, the production cost of polycrystalline silicon will be effectively reduced.

[0003] Currently, the production of dichlorosilane mostly uses catalysts developed by Union Carbide Corporation; most of the catalysts are weakly basic anion exchange resins, and the trade names are Amberlyst A-21 and Dowex MWA-1, respectively. Chinese patent (CN108516555A) describes a method for preparing dichlorosilane from weakly basic anion exchange resin as a disproportionation catalyst and using trichlorosilane as a raw material, and the final electronic grade dichlorosilane purity can reach 5N (99.999%). Similarly, patent (CN107500299A) uses an amine-based macroporous weakly basic anion exchange resin to obtain dichlorosilane with a purity of 4N (99.99%). Due to the disadvantages of resin-type catalysts such as easy aging, degradation, loss, and contamination of products, patent (CN105000564A) develops a method for preparing dichlorosilane by disproportionation using ionic liquid as a catalyst. The ionic liquid used as a catalyst has a high boiling point, is easy to separate from the product, and is not easily carried away by chlorosilane or silane products, thereby avoiding contamination of the product and being easy to recycle. Although the above-mentioned methods produce dichlorosilane with high purity, the single-pass conversion rate is relatively low due to the thermal stability of the catalyst, which cannot improve the reaction temperature. In recent years, Japanese scientists have developed a new type of catalyst, namely a noble metal supported activated carbon catalyst, which is resistant to high temperature and high pressure, does not easily age and degrade, and has good selective conversion rate. BYD Company has also broken through this technology (CN103285863A) and developed an activated carbon supported cobalt catalyst with a yield of 12%.

[0004] The activated carbon needs to be pretreated before loading the metal, mainly using oxidizing agents such as nitric acid, hydrogen peroxide and ozone for oxidation treatment, so that surface functional groups are generated on the surface of the activated carbon, and then the metal particles are anchored. However, the oxidation of the activated carbon is time-consuming (generally 8-24 h of high-temperature reflux and then 2-8 h of standing), and the adsorption effect of the metal particles on the activated carbon is poor, which is easy to fall off, further leading to low catalytic efficiency of the catalyst. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a method for preparing dichlorohydrogen silicon by disproportionation and a molybdenum-based supported catalyst used therein.

[0006] To solve the above technical problems, the present application provides a preparation method (impregnation and calcination preparation of a molybdenum-based supported catalyst) for a molybdenum-based supported catalyst for preparing dichlorohydrogen silicon by disproportionation, comprising the following steps:

[0007] 1.1), in a lower alcohol as a solvent, first add o-phthalodinitrile as a ligand for dissolution (ultrasonic dissolution), then heat to 50-70℃, then add molybdenum salt and stir until dissolved, reflux for 2-12 h; after reflux (after the reflux time reaches), cool to 50-70℃ (at this time the system turns blue-violet, indicating that the metal and the ligand are successfully coordinated, and a blue-violet metal complex is generated), then add biomass material and disperse uniformly, then impregnate for 6-24 h, then filter, then wash the obtained solid after filtration to obtain the obtained product after loading; the molar ratio of the molybdenum salt to o-phthalodinitrile is 1:4-1:8; the mass ratio of the molybdenum salt to the biomass material is 1:5-1:100;

[0008] Note: The above reaction can be carried out in a dry and clean Schlenk tube;

[0009] 1.2), under a reducing atmosphere, heat the obtained product after loading obtained in step 1.1) to a calcination temperature and keep it at the temperature for 2-12 h, and the calcination temperature is 400℃-800℃;

[0010] After calcination, cool to room temperature to obtain a molybdenum-based supported catalyst (a catalyst for preparing dichlorohydrogen silicon by disproportionation).

[0011] Note: The obtained product after loading is placed in a quartz boat, heated in a tube furnace under a reducing atmosphere, and then kept at temperature for calcination.

[0012] As an improvement of the preparation method of the molybdenum-based supported catalyst of the present application, in step 1.1):

[0013] The molybdenum salt is molybdenum chloride (MoCl5) or molybdenum acetate ((CH3COO)4Mo2);

[0014] Lower alcohol is ethanol, propanol, n-butanol, isobutyl alcohol, n-pentanol, isopentyl alcohol.

[0015] Further improvement of the preparation method of the molybdenum-based supported catalyst of the present application:

[0016] The reducing atmosphere is: H2: inert gas = 1:9, NH3: inert gas = 1:9 or H2: NH3: inert gas = 1:1:8, which is a volume ratio; wherein the inert gas is N2, Ar or He.

[0017] Inert gas, the abbreviation of inert gas.

[0018] Further improvement of the preparation method of the molybdenum-based supported catalyst of the present application:

[0019] In the step 1.2), the heating and cooling rates are both 2-8℃ / min.

[0020] Further improvement of the preparation method of the molybdenum-based supported catalyst of the present application:

[0021] In the step 1.1), 50-150mL of solvent is used for every 1mmol of molybdenum salt.

[0022] Further improvement of the preparation method of the molybdenum-based supported catalyst of the present application:

[0023] The biomass material is powdered (over 100 mesh) rice husk, straw, corn cob, crab shell, shrimp shell, or powdered (over 100 mesh commercially available powdered) lignin, cellulose, chitin, chitosan.

[0024] Further improvement of the preparation method of the molybdenum-based supported catalyst of the present application: as preferred,

[0025] In the step 1.1), the reflux time is 6-12h (more preferably 6-10h); the mass ratio of molybdenum salt to biomass material is 1:10-1:50 (more preferably 1:15-1:45); and the impregnation time is 8-16h (more preferably 12-16h);

[0026] In the step 1.2), the calcination temperature is 550-750℃ (more preferably 600-700℃), the calcination time is 4-6h, and the heating and cooling rates are 4-6℃ / min.

[0027] The present application also simultaneously provides a method for preparing dichlorohydrogen silicon by disproportionation: using the molybdenum-based supported catalyst prepared by any of the above methods, comprising the following steps:

[0028] The molybdenum-based supported catalyst is added to a tubular fixed-bed reactor, and hydrogen is first introduced for high-temperature activation;

[0029] Then trichlorosilane is introduced, the reaction pressure is controlled at 0.1-1.0 MPa, and the reaction is carried out after the temperature is raised to the reaction temperature, until the reaction system is stable (i.e. the composition of the product obtained after the reaction is stable, which is generally achieved after 60 minutes of reaction, and the product composition is investigated in an online gas chromatograph), and the product is collected;

[0030] The reaction temperature is 100-400℃;

[0031] The flow rate of trichlorosilane is 5-30 sccm (standard cubic centimeter per minute), and the amount of the molybdenum-based supported catalyst in the tubular fixed-bed reactor is 1.0-3.0 g.

[0032] As an improvement of the method for preparing dichlorosilane by disproportionation according to the present application: the reaction temperature is 150-300℃, the reaction pressure is 0.3-1.0 MPa (more preferably 0.4-1.0 MPa), 1.0 g of the molybdenum-based supported catalyst, and the flow rate of trichlorosilane is 5-10 sccm.

[0033] As an improvement of the method for preparing dichlorosilane by disproportionation according to the present application: the temperature for hydrogen activation is 400±40℃, and the time is 2±0.2 h.

[0034] The reaction equation for preparing dichlorosilane by disproportionation according to the present application is as follows:

[0035]

[0036] Note: the above reaction equation is the equation for the main reaction, and under the above conditions, a small amount of disproportionation or recombination (the reverse reaction of disproportionation) of silicon tetrahydride, monochlorosilane, dichlorosilane, trichlorosilane, and tetrachlorosilane also occurs in the actual reaction, and the final product composition is composed of the equilibrium products of the above reactions.

[0037] The technical advantages of the present application are:

[0038] The present application introduces a metal ligand, which strengthens the adsorption strength of the metal on the carrier by the strong interaction between the ligand and the carrier, reduces the falling off of the metal, and improves the service life of the catalyst; due to the presence of the ligand, the metal atoms are difficult to aggregate, and the metal is mostly dispersed in the form of single atoms, greatly improving the dispersion degree of the metal and the utilization rate of the metal, thereby improving the catalytic activity of the catalyst.

[0039] The catalyst carrier (biomass material) used in the application is cheap and easy to obtain, and can be directly dispersed in a reaction solution of the molybdenum complex for impregnation without pretreatment, and the operation is simple; high-temperature calcination enhances the thermal stability of the catalyst, thereby allowing the preparation of dichlorosilane by disproportionation at a higher reaction temperature, and improving the yield of dichlorosilane, and the yield can be up to 21.23%. DETAILED DESCRIPTION

[0040] The application will be further described below in combination with specific examples, but the protection scope of the application is not limited to this:

[0041] In the application: the inner diameter of the tubular fixed bed reactor is 3 cm, and the length of the constant temperature zone is about 20 cm.

[0042] Example 1, a method for preparing dichlorosilane by disproportionation, the following steps are sequentially performed:

[0043] 1) Preparation of a molybdenum-based supported catalyst:

[0044] 1.1) Add ethanol 100 mL to a three-necked flask, then add o-phenylenedinitrile 0.512 g (4 mmol) and ultrasonically dissolve, then heat the solution to 60℃, add molybdenum pentachloride (MoCl5) 0.273 g (1 mmol) and stir, after the molybdenum pentachloride is dissolved, reflux the solution at the boiling point for 6 h, and the solution becomes dark purple; then cool to 60℃, and a small amount of blue-purple solid molybdenum complex is precipitated; then add rice husk powder 4.7 g and uniformly disperse together, and then immerse for 12 h; then filter to obtain a purple-black solid, and wash (wash the filtered solid, and then wash twice after the washing liquid is changed from yellow and clear to colorless and clear); and obtain the obtained product after loading (purple-black);

[0045] 1.2) Put the obtained product after loading into a quartz boat, and then put it into a tubular furnace, and heat to 600℃ at a heating rate of 5℃ / min under the protection of a reducing atmosphere, and keep the temperature at 600℃ for 4 h; the reducing atmosphere (atmosphere used for calcination) is H2: Ar = 1:9 in volume ratio;

[0046] Then, cool to room temperature at a cooling rate of 5℃ / min, and obtain the catalyst 3.28 g, wherein the molybdenum loading (calculated as metal) is 2.93 wt%.

[0047] 2) Put 1.0 g of catalyst obtained in step 1.2) into a tubular fixed bed reactor, which is connected to an on-line gas phase detection evaluation device. Helium is passed through the device at a flow rate of 5 sccm (5 ml / min at standard conditions) for 30 min to remove the impurities in the device. Hydrogen is passed through the device at a flow rate of 10 sccm, and the catalyst is activated at a temperature of 400 °C for 2 h (the flow rate of hydrogen is kept unchanged). Then, the hydrogen is cut off, and helium is passed through the device for 30 min to remove the hydrogen, and the temperature is lowered to 150 °C. The reaction pressure in the tubular fixed bed reactor is controlled to be 0.4 MPa. Then, trichlorosilane is passed through the device at a flow rate of 5 sccm, and the product composition is detected in the on-line gas phase detection evaluation device every 15 min. After 60 min of reaction, the reaction is stable. The product composition obtained after the reaction is stable is as follows: tetrachlorosilane: 12.85%, trichlorosilane: 68.12%, dichlorosilane: 16.28%, and others: 2.65%. The above % is the mass %.

[0048] The amount of trichlorosilane used is 30.235 mg every time the reaction is carried out for 1 min, and 4.922 mg of the target product dichlorosilane is obtained, so the yield is 16.28%.

[0049] Yield = mass of dichlorosilane / mass of trichlorosilane input.

[0050] Example 2, preparation of dichlorosilane by disproportionation method, the following steps are carried out in sequence:

[0051] 1) Preparation of molybdenum-based supported catalyst:

[0052] 1.1) In a three-necked flask, 100 mL of propanol is added, followed by ultrasonic dissolution of 0.512 g (4 mmol) of phthalonitrile, and then the solution is heated to 60 °C. 0.219 g (0.5 mmol) of molybdenum acetate ((CH3COO)4Mo2) is added and stirred. After the molybdenum acetate is completely dissolved, the solution turns dark purple. The solution is refluxed at boiling point for 6 h, and then the temperature is lowered to 60 °C. A small amount of blue-purple solid molybdenum complex precipitates. Then, 6.8 g of corn cob powder is added and dispersed together, and then soaked for 12 h. After filtration and washing, the obtained product after loading is obtained.

[0053] 1.2) The obtained product after loading is placed in a quartz boat, which is then placed in a tube furnace. Under the protection of a reducing atmosphere, the temperature is raised to 600 °C at a rate of 5 °C / min, and the temperature is maintained at 600 °C for 4 h. The reducing atmosphere (atmosphere used for calcination) is H2:Ar = 1:9 in volume ratio.

[0054] Then, the temperature is lowered to room temperature at a rate of 5 °C / min, and 3.86 g of catalyst is obtained, in which the molybdenum loading (calculated as metal) is 2.49 wt%.

[0055] 2), take the catalyst 1.0 g obtained in step 1.2) of the above and place it in a tubular fixed bed reactor, and the rest is the same as step 2) of Example 1;

[0056] The composition of the product obtained after stabilization is: tetrachlorosilane: 13.57%, trichlorosilane: 64.63%, dichlorosilane: 17.24%, and others: 4.56%.

[0057] Example 3, method for preparing dichlorosilane by disproportionation, the following steps are sequentially performed:

[0058] 1), preparation of a molybdenum-based supported catalyst:

[0059] 1.1), add n-butanol 100 mL to a three-necked flask, then add o-phenylenedinitrile 0.512 g (4 mmol) and ultrasonically dissolve, then heat the solution to 60°C, add molybdenum acetate ((CH3COO)4Mo2) 0.219 g (0.5 mmol) and stir, after the molybdenum acetate is completely dissolved, reflux the solution at boiling point for 8 h, then cool to 60°C, then add shrimp shell powder 9.8 g and disperse together, then immerse for 12 h; after filtration and washing, the obtained product after loading is obtained.

[0060] 1.2), place the obtained product after loading in a quartz boat, then place it in a tube furnace, and heat to 600°C at a heating rate of 5°C / min under the protection of a reducing atmosphere, and keep the temperature at 600°C for 4 h; the reducing atmosphere (atmosphere used for calcination) is NH3: Ar = 1:9 in volume ratio;

[0061] Then, cool to room temperature at a cooling rate of 5°C / min, and obtain the catalyst 6.13 g, wherein the molybdenum loading (calculated as metal) is 1.57 wt%.

[0062] 2), take the catalyst 1.0 g obtained in step 1.2) of the above and place it in a tubular fixed bed reactor, and the rest is the same as step 2) of Example 1;

[0063] The composition of the product obtained after stabilization is: tetrachlorosilane: 11.35%, trichlorosilane: 73.63%, dichlorosilane: 13.96%, and others: 1.05%.

[0064] Example 4, method for preparing dichlorosilane by disproportionation, the following steps are sequentially performed:

[0065] 1), preparation of a molybdenum-based supported catalyst:

[0066] 1.1), in a three-necked flask, isoamyl alcohol 100 mL was added, then o-phenylenedinitrile 0.512 g (4 mmol) was ultrasonically dissolved, then the solution was heated to 60°C, molybdenum acetate ((CH3COO)4Mo2) 0.219 g (0.5 mmol) was added and stirred, after the molybdenum acetate was completely dissolved, the solution was refluxed at boiling point for 8 h, then the temperature was lowered to 60°C, then lignin 9.8 g was added and dispersed together, then immersed for 12 h; after filtration and washing, the obtained product after loading was obtained;

[0067] 1.2), the obtained product after loading was placed in a quartz boat, then placed in a tube furnace, under the protection of a reducing atmosphere, heated to 700°C at a heating rate of 5°C / min, kept at 700°C for 4 h, the atmosphere used for calcination was H2:NH3:Ar = 1:1:8,

[0068] then cooled to room temperature at a cooling rate of 5°C / min, then the catalyst 6.68 g was obtained, wherein the molybdenum loading (calculated as metal) was 1.44 wt%.

[0069] 2), 1.0 g of the catalyst obtained in step 1.2) above was taken and placed in a tube fixed bed reactor, the rest was the same as step 2) of Example 1;

[0070] After stabilization, the composition of the obtained product was: tetra-chlorosilane: 16.71%, trichlorosilane: 61.42%, dichlorosilane: 19.33%, and others: 2.54%.

[0071] Example 5, preparation of dichlorosilane by disproportionation method, the following steps were sequentially performed:

[0072] 1), preparation of molybdenum-based supported catalyst:

[0073] 1.1), in a three-necked flask, isoamyl alcohol 100 mL was added, then o-phenylenedinitrile 0.512 g (4 mmol) was ultrasonically dissolved, then the solution was heated to 60°C, molybdenum acetate ((CH3COO)4Mo2) 0.219 g (0.5 mmol) was added and stirred, after the molybdenum acetate was completely dissolved, the solution was refluxed at boiling point for 8 h, then the temperature was lowered to 60°C, then lignin 9.8 g was added and dispersed together, then immersed for 12 h; after filtration and washing, the obtained product after loading was obtained;

[0074] 1.2), the obtained product after loading was placed in a quartz boat, then placed in a tube furnace, under the protection of a reducing atmosphere, heated to 700°C at a heating rate of 5°C / min, kept at 700°C for 4 h, the atmosphere used for calcination was H2:NH3:Ar = 1:1:8,

[0075] then cooled to room temperature at a cooling rate of 5°C / min, then the catalyst 6.68 g was obtained, wherein the molybdenum loading (calculated as metal) was 1.44 wt%.

[0076] 2) Put 1.0 g of the catalyst obtained in step 1.2) into a tubular fixed bed reactor, and the rest is identical to step 2) of Example 1.

[0077] The composition of the product obtained after stabilization is: tetrachlorosilane: 18.36%, trichlorosilane: 57.43%, dichlorosilane: 21.23%, and others: 2.98%.

[0078] In Comparative Example 1, the boiling reflux (the boiling temperature of isobutanol is about 108°C) in step 1.1) of Example 5 is changed to a temperature of 30°C, and the rest is identical to step 1.1) of Example 5. Even if the treatment time is extended to 12 h, the solution does not change color, and no blue-purple solid molybdenum complex is precipitated. Therefore, the molybdenum complex cannot be obtained in this case.

[0079] In Comparative Example 2, the calcination temperature for preparing the catalyst in step 1.2) of Example 5 is changed from 700°C to 400°C, and the rest is identical to Example 5.

[0080] The composition of the product obtained after stabilization is: tetrachlorosilane: 3.41%, trichlorosilane: 93.22%, dichlorosilane: 2.62%, and others: 0.75%.

[0081] In Comparative Example 3, the boiling reflux (the boiling temperature of isobutanol is about 108°C) in step 1.1) of Example 5 is changed to a temperature of 30°C, and the rest is identical to step 1.1) of Example 5. That is, the solution in which no solid molybdenum complex is precipitated is used as the impregnation liquid, and chitosan 9.8 g is impregnated for 12 h, and then filtered and washed.

[0082] The subsequent steps are identical to Example 5.

[0083] The composition of the product obtained after stabilization is: tetrachlorosilane: 2.16%, trichlorosilane: 95.48%, dichlorosilane: 1.38%, and others: 0.98%.

[0084] In Comparative Example 4, compared with Example 5, the use of o-phenylenedinitrile as the ligand of molybdenum is cancelled, that is, the amount of o-phenylenedinitrile is 0; and molybdenum acetate ((CH3COO)4Mo2) 0.219 g (0.5 mmol) is directly dissolved in isobutanol to be used as the impregnation liquid, and chitosan 9.8 g is impregnated for 12 h under the same operation conditions as in Example 5, and then filtered and washed.

[0085] The subsequent operation is identical to Example 5.

[0086] The composition of the product obtained after stabilization is: tetrachlorosilane: 4.16%, trichlorosilane: 89.64%, dichlorosilane: 5.37%, and others: 0.83%.

[0087] Comparative Example 5-1, compared with Example 5, ligand of molybdenum was changed from o-phenylenedinitrile to phenanthroline, amount remained unchanged, still 4 mmol, the rest was identical with Example 5.

[0088] The composition of the product obtained after stabilization was: tetrachlorosilane: 6.43%, trichlorosilane: 85.39%, dichlorosilane: 6.57%, and others: 1.61%.

[0089] Comparative Example 5-2, compared with Example 5, ligand of molybdenum was changed from o-phenylenedinitrile to ethylenediamine, amount remained unchanged, still 4 mmol, the rest was identical with Example 5.

[0090] The composition of the product obtained after stabilization was: tetrachlorosilane: 1.43%, trichlorosilane: 96.88%, dichlorosilane: 1.51%, and others: 0.18%.

[0091] Comparative Example 5-3, compared with Example 5, amount of molybdenum acetate remained unchanged, amount of o-phenylenedinitrile was changed, so that "molybdenum acetate: o-phenylenedinitrile" was changed from "1:8" to "1:3", the rest was identical with Example 5.

[0092] The composition of the product obtained after stabilization was: tetrachlorosilane: 6.43%, trichlorosilane: 85.39%, dichlorosilane: 6.57%, and others: 1.61%.

[0093] Comparative Example 6, compared with Example 5, activation of catalyst was cancelled, i.e. step 2) "hydrogen was passed in at a flow rate of 10 seem, and the catalyst was activated at a temperature of 400°C for 2 h; then, hydrogen was cut off, and helium was passed in for 30 min to exhaust hydrogen" was changed to "inert gas Ar was passed in at a flow rate of 10 seem, and the catalyst was treated at a temperature of 400°C for 2 h; then, Ar was cut off, and helium was passed in for 30 min to exhaust Ar", the rest was identical with Example 5.

[0094] The composition of the product obtained after stabilization was: tetrachlorosilane: 6.24%, trichlorosilane: 85.13%, dichlorosilane: 6.89%, and others: 1.74%.

[0095] Comparative Example 7, compared with Example 5, metal of active center was changed to cobalt, i.e. molybdenum acetate ((CH3COO)4Mo2) 0.219 g (0.5 mmol) was changed to cobalt acetate ((CH3COO)2Co) 0.089 g (0.5 mmol), the rest was identical with Example 5.

[0096] The composition of the product obtained after stabilization was: tetrachlorosilane: 7.12%, trichlorosilane: 83.61%, dichlorosilane: 7.56%, and others: 1.71%.

[0097] Comparative Example 8, compared with Example 5, "add chitosan 9.8 g" is changed to "add activated carbon 9.8 g", the rest is the same as Example 5.

[0098] The composition of the product obtained after stabilization is: tetrachlorosilane: 3.94%, trichlorosilane: 91.37%, dichlorosilane: 4.18%, and others: 0.51%.

[0099] Finally, it should be noted that the above are only some specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, but can also have many variations. All variations that can be directly derived or inferred from the disclosure of the present application by those of ordinary skill in the art should be considered within the scope of the present application.

Claims

1. A method for the preparation of a molybdenum-based supported catalyst for the disproportionation to produce dichlorosilane, characterized in that The method comprises the following steps: 1.1) dissolving o-phthalic dicarboxylic acid as a ligand in alcohol as a solvent, then heating to 50-70 DEG C, adding molybdenum salt and stirring until dissolved, refluxing for 2-12 hours at the boiling point of the solvent; after the refluxing, cooling to 50-70 DEG C, then adding biomass material and uniformly dispersing, then immersing for 6-24 hours, filtering, washing the obtained solid after filtering, and obtaining the obtained product after loading; The molar ratio of the molybdenum salt to o-phthalic dicarboxylic acid is 1:4-1:8, and the mass ratio of the molybdenum salt to biomass material is 1:5-1:100; The alcohol is ethanol, propanol, n-butanol, isobutanol, n-pentanol, or iso-pentanol; 1.2) heating the obtained product after loading obtained in step 1.1) to a calcination temperature under a reducing atmosphere, and then calcining for 2-12 hours; the calcination temperature is 400 DEG C-800 DEG C; After the calcination, cooling to room temperature, and obtaining the molybdenum-based supported catalyst.

2. The method for preparing a molybdenum-based supported catalyst according to claim 1, characterized in that In the step 1.1): The molybdenum salt is molybdenum chloride or molybdenum acetate.

3. The method for preparing a molybdenum-based supported catalyst according to claim 2, characterized in that The reducing atmosphere is any one of the following: H2: inert gas = 1:9, NH3: inert gas = 1:9, H2: NH3: inert gas = 1:1:8; The volume ratio; the inert gas is Ar or He.

4. The method for preparing the molybdenum-based supported catalyst according to claim 3, wherein: In the step 1.2), the heating and cooling rate is 2-8 DEG C / min.

5. The method for preparing the molybdenum-based supported catalyst according to claim 4, wherein: In the step 1.1), 50-150 mL of solvent is used for each 1 mmol of molybdenum salt.

6. The method for preparing the molybdenum-based supported catalyst according to any one of claims 1-5, wherein: The biomass material is powdered rice husk, straw, corn cob, crab shell, or shrimp shell, or powdered lignin, cellulose, chitin, or chitosan.

7. The method for preparing the molybdenum-based supported catalyst according to claim 6, wherein: In the step 1.1): The refluxing time is 6-12 hours, the mass ratio of the molybdenum salt to biomass material is 1:10-1:50, and the immersing time is 8-16 hours; In the step 1.2): The calcination temperature is 550 DEG C-750 DEG C, the calcination time is 4-6 hours, and the heating and cooling rate is 4-6 DEG C / min.

8. Process for the preparation of dichlorohydrosilicon by disproportionation, characterized in that: The molybdenum-based supported catalyst prepared by the method according to any one of claims 1-7 comprises the following steps: The molybdenum-based supported catalyst is added to a tubular fixed-bed reactor, and hydrogen is introduced to activate at a high temperature; Then trichlorosilane is introduced, the reaction pressure is controlled to be 0.1 MPa-1.0 MPa, the reaction temperature is raised, and the reaction is carried out until the reaction system is stable, and the product is collected; The reaction temperature is 100 DEG C-400 DEG C; The flow rate of the trichlorosilane is 5-30 sccm.

9. The method for preparing dichlorosilane by disproportionation according to claim 8, wherein: The reaction temperature is 150 DEG C-300 DEG C, and the reaction pressure is 0.3 MPa-1.0 MPa.

10. The method of disproportionation to produce dichlorosilane according to claim 8 or 9, characterized in that: The temperature of the hydrogen activation is 400±40 DEG C, and the time is 2±0.2 hours.

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