Si-based catalyst loaded with CuO in situ, preparation method of Si-based catalyst and application of Si-based catalyst in synthesis of trichlorosilane

Abstract

The invention discloses a preparation method of an in-situ CuO-loaded Si-based catalyst, which comprises the following steps: firstly, uniformly dissolving a copper-based precursor in a polar solvent, and adding a surfactant and silicon powder to form a uniform precursor dispersion liquid; the preparation method comprises the following steps: preparing Si powder, then sequentially carrying out atomization treatment, microwave treatment and heating drying treatment to effectively promote in-situ loading and highly uniform dispersion of a Cu element on the Si powder so as to obtain the Si-based catalyst, and by using the Si-based catalyst as a catalyst for synthesizing trichlorosilane, the reaction temperature and the dosage of the catalyst can be reduced, and the yield of trichlorosilane can be obviously improved. The preparation process disclosed by the invention is relatively low in energy consumption, relatively short in period and relatively low in preparation cost, and a new thought can be provided for preparation of the high-performance Si-based catalyst.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysis, and in particular relates to a Si-based catalyst loaded with CuO in situ, a preparation method thereof, and a method for synthesizing trichlorosilane. Background Art

[0002] Trichlorosilane is an extremely important organosilicon monomer. It is a colorless, transparent liquid with a pungent odor at room temperature and pressure. It can be dissolved in a variety of organic solvents such as benzene, ether, and heptane. Trichlorosilane is widely used in many fields: 1) It can be used to synthesize organosilanes, alkyl, aryl, and chlorosilanes containing organic functional groups. It is an important intermediate for the production of organosilicon products such as organosilane coupling agents and chlorosilanes; 2) In the photovoltaic and semiconductor fields, trichlorosilane is widely used as an important raw material for crystalline silicon solar cells; 3) In the integrated circuit manufacturing process, high-purity trichlorosilane is used as a key reaction gas for the preparation of silicon epitaxial wafers. With the rapid development of the integrated circuit industry, the demand for high-purity trichlorosilane is also growing. However, the source of high-purity trichlorosilane is limited, which restricts the development of the silicon material industry and related industrial chains.

[0003] There are many methods for preparing trichlorosilane, such as using a mixture of halosilanes and excess hydrogen or hydrogen chloride to pass through the surfaces of Al, Zn, and Fe; using aluminum chloride as a catalyst and chlorinating SiH4 with hydrogen chloride gas; reducing SiCl4 with hydrogen at high temperature; and using dry hydrogen chloride gas to chlorinate crude silicon or silicon alloys. Among them, the first three methods have many disadvantages such as low yield, cumbersome process, and high cost. The silicon hydrochlorination method using dry hydrogen chloride gas to chlorinate Si powder is more widely used. However, the existing silicon hydrochlorination method for pure Si powder usually requires a higher reaction temperature (above 300°C) and high energy consumption. Further exploration of simple, efficient, low-energy-consuming catalysts that can effectively improve the catalytic activity of trichlorosilane synthesis has important research and application significance. Summary of the invention

[0004] The main purpose of the present invention is to provide a Si-based catalyst with in-situ CuO loading to address the deficiencies of the prior art. The Si-based catalyst is used as a catalyst for the production of trichlorosilane, which can achieve high dispersion and contact between the catalyst and the raw material, effectively reduce the reaction temperature and the amount of catalyst, and significantly improve the yield of trichlorosilane, thereby providing an effective way for the efficient preparation of high-purity trichlorosilane.

[0005] To achieve the above, the technical solution adopted by the present invention is:

[0006] A method for preparing a Si-based catalyst loaded with CuO in situ comprises the following steps:

[0007] 1) dissolving the copper-based precursor in a polar solvent, ultrasonicating, stirring to form a clear and transparent Cu-based solution, and adding a surfactant to mix evenly;

[0008] 2) adding silicon powder to the solution obtained in step 1), stirring and ultrasonically dispersing to obtain a uniform precursor dispersion;

[0009] 3) atomizing the precursor dispersion obtained in step 2) to form aerosol droplets;

[0010] 4) introducing the aerosol droplets formed in step 3) into a microwave generator through a carrier gas for microwave treatment;

[0011] 5) The aerosol droplets treated in step 4) are introduced into a heating container through a carrier gas flow for drying, and the obtained dry powder is collected to obtain the Si-based catalyst with in-situ CuO loading.

[0012] In the above scheme, the Cu-based precursor can be selected from one or more of copper sulfate, copper chloride, copper nitrite, copper acetate, copper nitrate, copper oxalate, copper phosphate, copper formate, copper oxalate, copper phthalate, bis(diethyl)copper phosphate, dimethoxide copper, diethoxide copper, etc.

[0013] In the above scheme, the polar solvent can be selected from one or more of water, ethanol, methanol, carbon tetrachloride, propanol, acetone, acetonitrile, etc., preferably water.

[0014] In the above scheme, the concentration of the Cu-based solution is 0.01-100 g / L.

[0015] Furthermore, in step 1), the ultrasonic time is 0.5-6h, preferably 1-2h; the stirring time is 0.5-6h, preferably 1-2h.

[0016] In the above scheme, the surfactant is one of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium stearate, sodium stearate, hexadecyltrimethylammonium bromide, ammonium dodecyl sulfate, benzalkonium chloride, polyvinyl pyrrolidone, polysorbate, alkyl glycoside and the like.

[0017] In the above scheme, the mass ratio of the copper-based precursor introduced in step 1) to the surfactant is 6-100:1.

[0018] In the above scheme, the silicon powder is commercial silicon powder, and the size is one or more of 20-60nm, 60-100nm, 100-200nm, 200-500nm, 500-1000nm, 1000-3000nm, preferably 100-200nm.

[0019] Preferably, the standard deviation of the particle size of the silicon powder is <5%.

[0020] In the above scheme, the stirring time in step 2) is 0.5-6h, preferably 1-2h; the ultrasonic time is 0.5-6h, preferably 1-2h.

[0021] Furthermore, the Cu introduced into the solution in step 2) accounts for 0.01-50% of the mass of the Si powder, preferably 10-20%.

[0022] In the above scheme, the atomization treatment in step 3) uses a polydisperse aerosol generator, specifically a commercial atomizer, and the aerosol droplet size formed is not greater than 50 μm.

[0023] Furthermore, the atomizing gas flow used in the atomization treatment is one or more of N2, nitrogen, argon, and helium, and the atomization pressure is 0.02-0.3MPa.

[0024] In the above scheme, the microwave power used in the microwave treatment is 200-1000W and the time is 1-30min.

[0025] In the above scheme, the drying treatment temperature used in step 4) is 200-1000° C., preferably 500-700° C.; the residence time (drying time) is 0.1 s-10 min.

[0026] In the above scheme, the carrier gas is one or more of nitrogen, argon, and helium, and its flow rate is 30-50 mL / min.

[0027] The Si-based catalyst prepared according to the above scheme has a chemical composition including Si and CuO, and the Cu element is highly dispersed on the Si powder and can be evenly distributed inside and outside the catalyst. The particle size is 100-5000nm, preferably 500-2000nm; the number of active centers can be effectively increased, and it is used as a catalyst for synthesizing trichlorosilane, which is beneficial to reducing the reaction temperature and the amount of catalyst, and significantly improving the yield of trichlorosilane.

[0028] Furthermore, when the Si-based catalyst is used to synthesize trichlorosilane, the reaction temperature can be reduced to 250-270° C., and the amount of the catalyst used accounts for 1-10% of the molar amount of HCl introduced in the synthesis of trichlorosilane.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1) The present invention uniformly disperses the copper-based precursor and silicon powder in a polar solvent, utilizes a surfactant and combines atomization treatment, microwave treatment and heating and drying treatment means to promote the effective loading and highly uniform dispersion of the Cu element on the Si powder, which can effectively increase the number of active centers, and uses it as a catalyst for synthesizing trichlorosilane, which is beneficial to reducing the reaction temperature and the amount of catalyst, and significantly improving the yield of trichlorosilane;

[0031] 2) The polydisperse aerosol generator used in the present invention atomizes the precursor solution into small droplets to produce aerosol droplets with wide distribution ranging from a few nanometers to tens of microns. This method has a large output, can be mass-produced, and takes less time. It can make up for the shortcomings of low output and high cost of monodisperse aerosol generators, and can also make up for the shortcoming of long time consumption of homogeneous precipitation method.

[0032] 3) The preparation cost of the present invention is low (low energy consumption and short cycle), the raw materials are easily available, and the effective loading and highly uniform dispersion of the Cu element on the Si powder can be achieved, so that the Si powder can be used as both a carrier and a raw material to participate in the reaction, thereby improving the reaction conversion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the XRD pattern of the catalyst obtained in Example 1.

[0034] Figure 2 SEM images of the silicon powder (a, b) used in Example 1 and the prepared Cu-doped Si powder (c, d).

[0035] Figure 3 This is the mapping diagram of the catalyst obtained in Example 1.

[0036] Figure 4 This is the EDS graph of the catalyst obtained in Example 1.

[0037] Figure 5 This is a schematic diagram of the preparation process of the catalyst obtained in Example 1. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0041] 1) Weigh 1.506 g of copper nitrate trihydrate and dissolve it in 50 mL of deionized water. After ultrasonication for 1 hour, stir for 1 hour to form a uniform blue clear solution. Add 0.2 g of hexadecyltrimethylammonium bromide and stir to mix evenly.

[0042] 2) Weigh 2 g of silicon powder with a particle size of 100-200 nm, add it to the solution prepared in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0043] 3) transferring the uniformly dispersed precursor solution to an atomizer for atomization, wherein the atomizing gas is N2 and the atomizing pressure is 0.1 MPa to form aerosol droplets;

[0044] 4) The aerosol droplets formed in step 3) were introduced into a microwave generator through a carrier gas (nitrogen, flow rate of 30 mL / min) for microwave treatment, the microwave reaction time was 700 W, and the reaction time was 10 min;

[0045] 5) The dispersion was atomized under nitrogen flow conditions and then transferred to a tubular furnace with the air flow for high temperature treatment. The temperature of the tubular furnace was 600° C., the air flow rate was 50 mL / min, the droplet residence time was about 10 s, and the tail powder collection device was set to 70° C. to collect the powder, which was the Si-based catalyst loaded with CuO in situ.

[0046] The XRD and SEM images of the catalyst obtained in this example are shown in Figure 1 and Figure 2 It can be seen that the particle size of the obtained catalyst particles is about 1-2 μm, and the catalyst component is a composite of CuO and Si.

[0047] Figure 3 This is the mapping diagram of the catalyst obtained in this example. It can be seen that the Cu element is highly evenly dispersed on the Si powder; Figure 4 This is the EDS image of the catalyst prepared in Example 1. It can be clearly seen that the dispersion of Cu and Si is very uniform.

[0048] Table 1 shows the element contents of the catalyst obtained in Example 1 (only the metal content was detected).

[0049]

[0050] The catalyst obtained in this example is applied to prepare trichlorosilane from HCl, and the specific steps are as follows: the catalyst is pressed into tablets and then sieved, and placed in a fixed bed (reaction inner diameter 20 mm, tube length 50 cm) (the amount of catalyst accounts for 5% of the molar amount of HCl introduced in the synthesis of trichlorosilane), purged with N2 for 1 hour, the temperature is raised to 250°C, HCl is introduced, the flow rate is set to 15 mL / min, the reaction pressure is 1 MPa, the reaction time is 4 hours, the product after the reaction is condensed by a condenser and collected with toluene, the remaining gas is collected with an alkaline liquid and then emptied, the collected mixed solution is fixed to volume and then quantitatively analyzed by gas chromatography (Agilent 8890, DB-1 chromatographic column, TCD detector), the trichlorosilane content in the obtained product is 76.75%, and the conversion rate calculated based on the Si content is 30.49%.

[0051] Example 2

[0052] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0053] 1) Weigh 0.753 g of copper nitrate trihydrate and dissolve it in 30 mL of deionized water. After ultrasonication for 1 hour, stir for 1 hour to form a uniform blue clear solution. Add 0.2 g of dodecyl ammonium sulfate and stir to mix evenly.

[0054] 2) Weigh 2 g of silicon powder with a particle size of 100-200 nm, add it to the solution prepared in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0055] 3) transferring the obtained dispersion precursor to an atomizer for atomization to form aerosol droplets;

[0056] 4) The aerosol droplets formed in step 3) were introduced into a microwave generator through a carrier gas (nitrogen, flow rate of 15 mL / min) for microwave treatment, the microwave reaction time was 500 W, and the reaction time was 20 min;

[0057] 5) Atomizing the dispersion to form aerosol droplets under nitrogen flow conditions and then transferring them to a tubular furnace with the air flow for high-temperature treatment. The temperature of the tubular furnace is 800° C., the air flow rate is 100 mL / min, and the droplet residence time is about 5 s. The tail powder collection device is set to 70° C. to collect powders to obtain a Si-based catalyst loaded with CuO in situ.

[0058] Application Examples

[0059] The catalyst obtained in this example is used to prepare trichlorosilane: the catalyst is pressed into tablets and then sieved, and placed in a fixed bed (reaction inner diameter 20 mm, tube length 50 cm) (the amount of catalyst accounts for 10% of the molar amount of HCl introduced in the synthesis of trichlorosilane), N2 is used for purging for 1 hour, the temperature is raised to 270°C, HCl is introduced, the flow rate is set to 15 mL / min, the reaction pressure is 1 MPa, the reaction time is 4 hours, the product after the reaction is condensed by a condenser and collected with toluene, the remaining gas is collected with an alkaline liquid and then emptied, the collected mixed solution is fixed to volume and then quantitatively analyzed by gas chromatography (Agilent 8890, DB-1 chromatographic column, TCD detector), the trichlorosilane content in the obtained product is 78.16%, and the conversion rate calculated based on the Si content is 35.15%.

[0060] Example 3

[0061] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0062] 1) Weigh 0.376 g of copper nitrate trihydrate and dissolve it in 40 mL of deionized water. After ultrasonication for 1 hour, stir for 1 hour to form a uniform blue clear solution. Add 0.1 g of sodium dodecyl sulfate and stir to mix evenly.

[0063] 2) Weigh 4 g of silicon powder with a particle size of 100-200 nm, add it to the solution obtained in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0064] 3) transferring the obtained dispersion precursor to an atomizer for atomization to form aerosol droplets;

[0065] 4) The aerosol droplets formed in step 3) were introduced into a microwave generator through a carrier gas (nitrogen, flow rate of 20 mL / min) for microwave treatment, the microwave reaction time was 700 W, and the reaction time was 10 min;

[0066] 5) The dispersion was atomized under nitrogen flow conditions to form aerosol droplets, which were then transferred to a tubular furnace with the air flow for high-temperature treatment. The temperature of the tubular furnace was 500° C., the air flow rate was 80 mL / min, and the droplet residence time was about 5 s. The tail powder collection device was set to 70° C. to collect powder, which was the Si-based catalyst loaded with CuO in situ.

[0067] Application Examples

[0068] The catalyst obtained in this example is used to prepare trichlorosilane: the catalyst is pressed into tablets and then sieved, and placed in a fixed bed (reaction inner diameter 20 mm, tube length 50 cm) (the amount of catalyst accounts for 5% of the molar amount of HCl introduced in the synthesis of trichlorosilane), N2 is used for purging for 1 hour, the temperature is raised to 260°C, HCl is introduced, the flow rate is set to 15 mL / min, the reaction pressure is 1 MPa, the reaction time is 4 hours, the product after the reaction is condensed by a condenser and collected with toluene, the remaining gas is collected with an alkaline liquid and then emptied, the collected mixed solution is fixed to volume and then quantitatively analyzed by gas chromatography (Agilent 8890, DB-1 chromatographic column, TCD detector), the trichlorosilane content in the obtained product is 72.21%, and the conversion rate calculated based on the Si content is 32.15%.

[0069] Example 4

[0070] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0071] 1) Weigh 0.753 g of copper nitrate trihydrate and dissolve it in 50 mL of deionized water. After ultrasonication for 1 h, stir for 1 h to form a uniform blue clear solution. Add 0.1 g of polyvinyl pyrrolidone;

[0072] 2) Weigh 3 g of silicon powder with a particle size of 100-200 nm, add it to the solution prepared in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0073] 3) transferring the uniformly dispersed precursor solution to an atomizer for atomization to form aerosol droplets;

[0074] 4) The aerosol droplets formed in step 3) were introduced into a microwave generator through a carrier gas (nitrogen, flow rate of 20 mL / min) for microwave treatment, the microwave reaction time was 1000 W, and the reaction time was 5 min;

[0075] 5) The dispersion was atomized under nitrogen flow conditions and then transferred to a tubular furnace with the air flow for high temperature treatment. The temperature of the tubular furnace was 400° C., the air flow rate was 100 mL / min, and the droplet residence time was about 5 s. The tail powder collection device was set to 70° C. to collect powder, which was the Si-based catalyst loaded with CuO in situ.

[0076] The method of using the obtained catalyst to prepare trichlorosilane is as follows: the catalyst is pressed into tablets and then sieved, and placed in a fixed bed (reaction inner diameter 20 mm, tube length 50 cm) (the amount of catalyst accounts for 8% of the molar amount of HCl introduced in the synthesis of trichlorosilane), N2 is used for purging for 1 hour, the temperature is raised to 300° C., HCl is introduced, the flow rate is set to 15 mL / min, the reaction pressure is 1 MPa, the reaction time is 4 hours, the product after the reaction is condensed by a condenser and then collected with toluene, the remaining gas is collected with an alkaline liquid and then emptied, the collected mixed solution is fixed to volume and then quantitatively analyzed by gas chromatography (Agilent 8890, DB-1 chromatographic column, TCD detector), the trichlorosilane content in the obtained product is 77.54%, and the conversion rate calculated based on the Si content is 37.12%.

[0077] Example 5

[0078] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0079] 1) Weigh 0.753 g of copper nitrate trihydrate and dissolve it in 100 mL of deionized water. Ultrasonicate for 1 h and stir for 1 h to form a uniform blue clear solution. Add 0.1 g of polysorbate;

[0080] 2) Weigh 2.5 g of silicon powder with a particle size of 100-200 nm, add it to the solution prepared in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0081] 3) transferring the uniformly dispersed precursor solution to an atomizer for atomization to form aerosol droplets;

[0082] 4) The aerosol droplets formed in step 3) were introduced into a microwave generator through a carrier gas (nitrogen, flow rate of 20 mL / min) for microwave treatment, the microwave reaction time was 300 W, and the reaction time was 8 min;

[0083] 5) The dispersion was atomized under nitrogen flow and then transferred to a tubular furnace for high temperature treatment. The temperature of the tubular furnace was 800° C., the air flow rate was 60 mL / min, and the residence time of the droplets was about 5 s. The tail powder collection device was set to 70° C. to collect the powder, which was the Si-based catalyst loaded with CuO in situ.

[0084] The method of using the obtained catalyst to prepare trichlorosilane is as follows: the catalyst is pressed into tablets and then sieved, and placed in a fixed bed (reaction inner diameter 20 mm, tube length 50 cm) (the amount of catalyst accounts for 6% of the molar amount of HCl introduced in the synthesis of trichlorosilane), N2 is used for purging for 1 hour, the temperature is raised to 260°C, HCl is introduced, the flow rate is set to 15 mL / min, the reaction pressure is 1 MPa, the reaction time is 4 hours, the product after the reaction is condensed by a condenser and then collected with toluene, the remaining gas is collected with an alkaline liquid and then emptied, the collected mixed liquid is fixed to volume and then quantitatively analyzed by gas chromatography (Agilent 8890, DB-1 chromatographic column, TCD detector), the trichlorosilane content in the obtained product is 74.49%, and the conversion rate calculated based on the Si content is 32.42%.

[0085] Comparative Example

[0086] An in-situ CuO-loaded Si-based catalyst, the preparation method of which comprises the following steps:

[0087] 1) Weigh 1.506 g of copper nitrate trihydrate and dissolve it in 50 mL of deionized water. After ultrasonication for 1 hour, stir for 1 hour to form a uniform blue clear solution. Add 0.2 g of hexadecyltrimethylammonium bromide;

[0088] 2) Weigh 2 g of silicon powder with a particle size of 100-200 nm, add it to the solution prepared in step 1) under stirring, then stir for 1 hour and ultrasonicate for 1 hour to form a dispersion precursor;

[0089] 3) transferring the uniformly dispersed precursor solution to an atomizer for atomization to form aerosol droplets;

[0090] 4) The dispersion was atomized under nitrogen flow conditions and then transferred to a tube furnace with the air flow for high-temperature treatment. The temperature of the tube furnace was 800° C., the air flow rate was 60 mL / min, and the droplet residence time was about 5 s. The tail powder collection device was set to 70° C. to collect the powder, which was the Cu-doped Si powder catalyst. The powder was then used to prepare trichlorosilane from HCl.

[0091] Referring to the application method described in Example 1 (the amount of catalyst used accounted for 5% of the molar amount of HCl introduced in the synthesis of trichlorosilane) and the quantitative analysis method, the results showed that the trichlorosilane content in the product obtained in this comparative example was 46.41%, the conversion rate calculated based on the Si content was 34.56%, and the dispersion effect of Cu in the catalyst was poor, and the corresponding catalytic effect was poor.

[0092] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0094] In addition, the various embodiments of the present invention may be combined in any way, and as long as they do not violate the concept of the present invention, they shall also be regarded as the contents disclosed by the present invention. The present invention is not limited to the above-mentioned embodiments. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as within the scope of protection of the present invention. The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for preparing a Si-based catalyst loaded with CuO in situ, characterized in that: The following steps are involved: 1) dissolving the copper-based precursor in a polar solvent, ultrasonicating, stirring to form a clear and transparent Cu-based solution, and adding a surfactant to mix evenly; 2) adding silicon powder to the solution obtained in step 1), stirring and ultrasonically dispersing to obtain a uniform precursor dispersion; 3) atomizing the precursor dispersion obtained in step 2) to form aerosol droplets; 4) introducing the aerosol droplets formed in step 3) into a microwave generator through a carrier gas for microwave treatment; 5) The aerosol droplets treated in step 4) are introduced into a heating container through a carrier gas flow for drying, and the obtained dry powder is collected to obtain the Si-based catalyst loaded with CuO in situ.

2. The preparation method according to claim 1, characterized in that: The Cu-based precursor is one or more of copper sulfate, copper chloride, copper nitrite, copper acetate, copper nitrate, copper oxalate, copper phosphate, copper formate, copper oxalate, copper phthalate, bis(diethyl)copper phosphate, dimethoxycopper, and diethoxycopper.

3. The preparation method according to claim 1, characterized in that: The polar solvent is one or more of water, ethanol, methanol, carbon tetrachloride, propanol, acetone and acetonitrile.

4. The preparation method according to claim 1, characterized in that: The size of the silicon powder is one or more of 20-60nm, 60-100nm, 100-200nm, 200-500nm, 500-1000nm, and 1000-3000nm.

5. The preparation method according to claim 1, characterized in that: The surfactant is one of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium stearate, sodium stearate, hexadecyltrimethylammonium bromide, ammonium dodecyl sulfate, benzalkonium chloride, polyvinyl pyrrolidone, polysorbate, and alkyl glycoside.

6. The preparation method according to claim 1, characterized in that: The Cu introduced into the solution in step 2) accounts for 0.01-50% of the mass of Si powder.

7. The preparation method according to claim 1, characterized in that: The microwave treatment uses a microwave power of 200-1000W and a time of 1-30min.

8. The preparation method according to claim 1, characterized in that: The drying treatment temperature used in step 4) is 200-1000° C. and the time is 0.1 s-10 min.

9. The Si-based catalyst loaded with CuO in situ prepared by the preparation method according to any one of claims 1 to 8, characterized in that: Its chemical composition includes Si and CuO, and the Cu element is evenly dispersed on the Si powder, and its particle size is 100-5000nm.

10. Use of the Si-based catalyst in situ loaded with CuO according to claim 9 in the field of synthesizing trichlorosilane.

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