阅读说明：本技术 一种铜基复合金属氧化物介晶微球及其制备方法和用途 (Copper-based composite metal oxide mesomorphic microsphere and preparation method and application thereof ) 是由 苏发兵 纪永军 翟世辉 谭强强 于 2019-10-17 设计创作，主要内容包括：本发明涉及一种铜基复合金属氧化物介晶微球及其制备方法和用途。所述铜基复合金属氧化物介晶微球具有中空核壳结构,从内向外依次为内核、空隙、外壳,所述内核和外壳均由取向一致的纳米颗粒构成,所述纳米颗粒包含氧化铜纳米颗粒和金属M的氧化物纳米颗粒,所述金属M包括Ge、Sn、Pb、In或过渡金属元素中的任意一种或至少两种的组合。本发明所述铜基复合金属氧化物介晶微球采用溶剂热法合成,条件温和,且不使用表面活性剂和模板剂,成本较低,对环境友好；所述铜基复合金属氧化物介晶微球将其用作太阳能晶硅原料三氯氢硅合成反应的催化剂时,与传统非催化工业生产过程相比,可显著提高三氯氢硅的选择性,高达98.0％。(The invention relates to a copper-based composite metal oxide mesomorphic microsphere and a preparation method and application thereof. The copper-based composite metal oxide mesomorphic microsphere is of a hollow core-shell structure and sequentially comprises an inner core, a gap and an outer shell from inside to outside, wherein the inner core and the outer shell are respectively composed of nano particles with consistent orientation, the nano particles comprise copper oxide nano particles and oxide nano particles of metal M, and the metal M comprises any one or combination of at least two of Ge, Sn, Pb, In or transition metal elements. The copper-based composite metal oxide mesomorphic microspheres are synthesized by a solvothermal method, the conditions are mild, a surfactant and a template agent are not used, the cost is low, and the environment is protected; when the copper-based composite metal oxide mesomorphic microspheres are used as a catalyst for a trichlorosilane synthesis reaction of a solar crystalline silicon raw material, compared with the traditional non-catalytic industrial production process, the selectivity of trichlorosilane can be remarkably improved to 98.0%.)

1. The copper-based composite metal oxide mesomorphic microspheres are characterized by having a hollow core-shell structure, wherein a core, a gap and a shell are sequentially arranged from inside to outside, the core and the shell are respectively composed of nanoparticles with consistent orientation, and the nanoparticles comprise copper oxide nanoparticles and oxide nanoparticles of metal M.

2. The mesogenic microsphere of claim 1, wherein the metal M comprises any one or a combination of at least two of Ge, Sn, Pb, In, or a transition metal element;

preferably, the content of the oxide of the metal M is 1-20%, preferably 2-5% by mass of the mesogenic microsphere of 100%;

preferably, the particle size of the copper-based composite metal oxide mesomorphic microballoon is 10-20 μm;

preferably, the shell and the core of the copper-based composite metal oxide mesomorphic microsphere both have mesoporous structures;

preferably, the average pore diameter of the copper-based composite metal oxide mesomorphic microballoon is 12-40nm, preferably 15-25 nm.

3. The mesogenic microsphere as claimed in claim 1 or 2, wherein a nanoscale interface is formed between different oxide nanoparticles in the copper-based composite metal oxide mesogenic microsphere.

4. A method of preparing mesogenic microspheres according to any of the claims 1-3, comprising the steps of:

(1) dissolving acetic acid and/or acetate in a salt solution containing Cu precursor salt and metal M precursor salt, and mixing to obtain a mixed solution; or

Dissolving acetic acid and/or acetate, adding Cu precursor salt and metal M precursor salt, and mixing to obtain a mixed solution;

(2) carrying out solvent thermal reaction on the mixed solution obtained in the step (1), carrying out precipitation reaction, cooling, separating and collecting a solid phase;

(3) and (3) roasting the solid phase obtained in the step (2) in an aerobic environment to obtain the copper-based composite metal oxide mesomorphic microspheres.

5. The method for preparing mesogenic microspheres according to claim 4, wherein the method for preparing the salt solution containing Cu precursor salt and metal M precursor salt in step (1) comprises: dissolving and mixing Cu precursor salt and metal M precursor salt to obtain salt solution;

preferably, the solvent of the mixed solution comprises any one of or a combination of at least two of N, N-dimethylformamide, ethylenediamine or oleylamine;

preferably, the Cu precursor salt and the metal M precursor salt each independently comprise any one of or a combination of at least two of a nitrate, an oxalate, a chloride, or a sulfate or a bromide salt;

preferably, the acetate salt comprises any one of ammonium acetate, sodium acetate or potassium acetate or a combination of at least two thereof.

6. The production method according to claim 4 or 5, wherein the concentration of the Cu precursor salt in the salt solution in step (1) is 0.002 to 0.07mol/L, preferably 0.02 to 0.05 mol/L;

preferably, the molar volume ratio of the added acetic acid and/or acetate to the solvent is more than or equal to 0.07mol/L, and preferably 0.07-1.4 mol/L;

preferably, the molar ratio of Cu in the Cu precursor salt to M in the metal M precursor salt is (1-100):1, preferably (5-20): 1;

preferably, the mixing means comprises stirring;

preferably, the dissolution time is 0.05-24h, preferably 0.1-1 h.

7. The method according to any one of claims 4-6, wherein the temperature of the solvothermal reaction in step (2) is 130-220 ℃, preferably 140-160 ℃;

preferably, the solvothermal reaction time is 3-30h, preferably 6-14 h;

preferably, the cooling mode comprises natural cooling and/or cooling in cooling liquid;

preferably, the cooling temperature is 20-60 ℃, preferably 30-40 ℃;

preferably, the means of separation comprises any one or a combination of at least two of filtration, suction filtration or centrifugation.

8. The production method according to any one of claims 4 to 7, wherein the oxygen-containing atmosphere in step (3) comprises oxygen and/or air;

preferably, the roasting temperature is 150-900 ℃, preferably 300-600 ℃;

preferably, the roasting time is 1-24h, preferably 2-8 h;

preferably, the solid phase in the step (3) is washed and dried and then is roasted in an oxygen atmosphere;

preferably, the washing liquid used for washing comprises any one of water, ethanol or acetone or a combination of at least two of the above;

preferably, the number of washing is 3 or more, preferably 3 to 4;

preferably, the drying manner comprises any one or a combination of at least two of air drying, vacuum drying or freeze drying;

preferably, the temperature of the drying is 50-150 ℃, preferably 60-100 ℃;

preferably, the drying time is 6-30h, preferably 9-15 h.

9. The method for preparing according to any one of claims 4 to 8, comprising the steps of:

(1) dissolving acetic acid and/or acetate in a solution containing Cu precursor salt and metal M precursor salt, and stirring for 0.05-24h for mixing to obtain a mixed solution; or

Dissolving acetic acid and/or acetate in a solvent, adding a Cu precursor salt and a metal M precursor salt, and stirring and mixing for 0.05-24h to obtain a mixed solution;

the solvent of the mixed solution comprises any one or the combination of at least two of N, N-dimethylformamide, ethylenediamine or oleylamine;

the acetate comprises any one or the combination of at least two of ammonium acetate, sodium acetate or potassium acetate;

the molar volume ratio of the added acetic acid and/or acetate to the solvent is more than or equal to 0.07 mol/L;

the Cu precursor salt and the metal M precursor salt are respectively and independently selected from any one or a combination of at least two of nitrate, oxalate, chloride or sulfate or bromide; controlling the concentration of Cu precursor salt in the salt solution to be 0.002-0.07mol/L, wherein the molar ratio of Cu in the Cu precursor salt to M in the metal M precursor salt is (1-100): 1;

(2) carrying out solvothermal reaction on the mixed solution obtained in the step (1) at the temperature of 130-220 ℃ for 3-10h to generate precipitation reaction, cooling to 20-60 ℃, separating, and collecting a solid phase;

the separation mode comprises any one or the combination of at least two of filtration, suction filtration and centrifugation;

(3) and (3) washing the solid phase obtained in the step (2), drying at 50-150 ℃ for 6-30h, and then roasting at 900 ℃ for 1-24h in an aerobic environment to obtain the copper-based composite metal oxide mesomorphic microsphere.

10. A catalyst for a solar crystalline silicon raw material trichlorosilane synthesis reaction is characterized in that the catalyst adopts the copper-based composite metal oxide mesomorphic microspheres as claimed in any one of claims 1-3.

Technical Field

The invention relates to the technical field of micro-nano material synthesis, in particular to a copper-based composite metal oxide mesomorphic microsphere and a preparation method and application thereof.

Background

The hollow core-shell structure is a unique core-shell structure, and a layer of gap is formed between the core and the shell. This particular morphology has significant structural advantages in catalytic applications: the reaction phase can enter the inner cavity through the shell pore canal, the core can be fully contacted with the reaction phase, the function of the core is fully exerted, and meanwhile, the shell with hard outer part can provide full protection for the core inside. The method for synthesizing the material with the hollow core-shell structure mainly comprises a hard template method and a soft template method, but the hard template method needs to carry out multi-step and multi-time wrapping on the surface of a template to form a multi-layer core-shell structure, then selectively remove a middle template layer of double-layer core-shell particles or partially corrode a core/shell to form hollow core-shell structure particles, so that the synthesis steps are multiple, and the experimental conditions are complex; the soft template method usually uses a surfactant as a soft template, which increases the cost and pollutes the environment.

In recent years, much attention has been paid to the synthesis of superstructure materials by nanomaterial self-assembly, mesogens (mesocrystals) being a type of nanoparticle superstructure made by nanocrystalline grains self-assembled in a crystallographically ordered manner, due to the incorporation of individual nanocrystalsRice particles and ordered mesoscale (hundreds of nanometers to several micrometers) structures have been the focus of attention, allowing mesogens to create some new collective properties. There are over 50 kinds of mesogenic materials prepared by different synthesis methods so far (y.q.liu et al, CrystEngComm,2014,16,5948), which can be classified into metal mesogenic materials, metal oxide mesogenic materials and complex compound mesogenic materials according to the components, and most of them are added with surfactant and template during the synthesis process. CN104058453A discloses a spherical anatase TiO with controllable size₂The key technology of mesomorphic crystal is to utilize benzoic acid as surfactant and to prepare size controllable spherical titanium ore type TiO by controlling benzoic acid content₂Mesogens. The specific method comprises the following steps: firstly, adding a proper amount of benzoic acid into an acetic acid solution, stirring to obtain a clear transparent solution, dropwise adding tetrabutyl titanate into the solution to generate white flocculent precipitate, carrying out hydrothermal treatment for 24 hours at 200 ℃, centrifuging, washing, drying by distillation to obtain a powder sample, and carrying out heat treatment at 400 ℃ to obtain spherical anatase TiO with controllable size₂Mesogens. However, the use of the surfactant affects the performance of mesomorphism, increases the cost and pollutes the environment.

CN101767835A discloses a magnetic controllable alpha-Fe₂O₃A liquid phase preparation method of mesomorphic microspheres. Using mixed solvent of water and ethanol as reaction medium, adding FeCl₃·6H₂Dissolving O and polyvinylpyrrolidone in a mixed solvent, and reacting under a certain condition; after the reaction is finished, the obtained product alpha-Fe₂O₃Centrifugally washing and drying to obtain the high-coercivity alpha-Fe with good magnetic controllability and room-temperature ferromagnetism₂O₃Mesogenic microspheres. The invention prepares magnetic alpha-Fe₂O₃Simple method of mesomorphic microballoon, product alpha-Fe₂O₃The size, the structure and the shape of the mesomorphic microballoon are easy to control, the yield is high, and the problem of alpha-Fe in the prior art is solved₂O₃The preparation process of the microsphere is complex, but the use of the polyvinylpyrrolidone has influence on the performance of the mesomorphic microsphere, and the production cost is increased.

Compared with other mesomorphic materials, the metal oxide mesomorphic material has wider application, but most reports in the literature are single-element metal oxide mesomorphic materials, and almost no report is provided about the synthesis and application of the binary/multi-element metal composite oxide mesomorphic material. Binary/multi-metal composite oxide mesogenic materials are likely to exhibit unique functional properties similar to nanocrystalline hybrid systems (m.r.buck et al, nat.chem.,2012,4, 37).

Therefore, if the hollow core-shell structure and the binary/multi-component composite metal oxide mesogen can be integrated to form a novel mesogen material with a unique structure, the hollow core-shell structure and the binary/multi-component composite metal oxide mesogen are very likely to show great application potential in the field of catalysis. Therefore, the development of a preparation method which has low cost, no surfactant addition, environmental friendliness, simplicity and universality is of great significance.

Trichlorosilane (SiHCl)₃) Is a main raw material for producing solar high-purity crystal silicon and is also an important intermediate for producing a silane coupling agent and other organic silicon products, and is industrially produced by hydrochlorination of metallurgical silicon, namely direct reaction of silicon powder (Si) and hydrogen chloride (HCl), and a large amount of by-product silicon tetrachloride (SiCl) is generated along with₄) The reaction equation is shown below. With the rapid development of the photovoltaic industry, SiHCl₃Demand also grows very rapidly, with demand exceeding 30 kilotons expected by the year 2020. No catalyst, SiHCl, is used in the current industrial production₃Selectivity of 80-85%, SiCl₄The selectivity was 15-20% (CN101665254A, CN101279734B), and therefore, SiHCl was further increased₃The selectivity of the method is high, the production cost of the high-purity crystalline silicon is reduced, and the method has important significance for the healthy development of the solar energy industry.

Disclosure of Invention

In view of the problems in the prior art, the copper-based metal oxide has wide and important application in the traditional chemical industry, and the invention provides a hollow core-shell structure copper-based composite metal oxide mesomorphic microsphere and a preparation method and application thereof. The method adopts cheap and easily-obtained raw materials, does not add any polymer or surfactant, and can synthesize the copper-based composite metal oxide mesomorphic microspheres with the hollow core-shell structures through simple process steps; when the catalyst is used as a catalyst for a solar crystalline silicon raw material trichlorosilane synthesis reaction, the selectivity and the yield of trichlorosilane can be obviously improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a copper-based composite metal oxide mesomorphic microsphere, which has a hollow core-shell structure, and comprises a core, a gap and a shell from inside to outside in sequence, wherein the core and the shell are both composed of nanoparticles with consistent orientation, and the nanoparticles comprise copper oxide nanoparticles and oxide nanoparticles of metal M.

According to the invention, the copper-based composite metal oxide mesomorphic microsphere has a hollow core-shell structure, the core, the gap and the shell are sequentially arranged from inside to outside, the core and the shell both have mesoporous structures, a reaction phase can enter the gap through a porous channel of a shell layer of the shell, and can be fully contacted with the core through the gap reaction phase, the mesoporous structure of the core increases the specific surface area of the mesomorphic microsphere, more active sites are provided for the reaction phase, the function of the core is fully exerted, and meanwhile, the shell layer of the shell can fully protect the core; a nanoscale interface is formed between the copper oxide nanoparticles in the mesomorphic microsphere and the oxide nanoparticles of the metal M, so that a high-efficiency charge transmission channel can be provided, and the catalytic activity and selectivity of the mesomorphic material are further improved.

Preferably, the metal M comprises any one of Ge, Sn, Pb, In or a transition metal element or a combination of at least two thereof, with typical but non-limiting combinations: ni and Zn, Zn and In, In and Ni, In and Fe, Ga and Fe, Mn, Ni and Co.

Preferably, the content of the oxide of the metal M is 1-20% by mass of 100%, for example, 1%, 2%, 3%, 5%, 8%, 10%, 12%, 14%, 16%, 17%, 18%, 19%, 20%, etc., and the oxide of the metal M can optimize the electronic structure of copper oxide, preferably 2-5%.

Preferably, the particle size of the copper-based composite metal oxide mesogenic microsphere is 10-20 μm, for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, and the like, and the particle size of the mesogenic microsphere can regulate and control the catalytic performance of the reaction.

Preferably, the shell and the core of the copper-based composite metal oxide mesomorphic microsphere both have mesoporous structures, the mesoporous structure of the shell can provide a faster mass transfer channel for a reaction phase, and the mesoporous structure of the core increases the specific surface area and provides more active sites for the reaction phase.

Preferably, the average pore diameter of the copper-based composite metal oxide mesogenic microspheres is 12-40nm, such as 12nm, 13nm, 14nm, 15nm, 18nm, 20nm, 22nm, 25nm, 27nm, 30nm, 33nm, 35nm, 36nm, 38nm, 39nm or 40nm, and the like, and the average pore diameter of the mesogenic microspheres can promote the diffusion of reactants and products, preferably 15-25 nm.

Preferably, a nanoscale interface is formed among different oxide nanoparticles in the copper-based composite metal oxide mesogenic microsphere, so that an efficient charge transmission channel can be provided.

In a second aspect, the present invention provides a method for preparing mesogenic microspheres as described in the first aspect above, comprising the steps of:

(1) dissolving acetic acid and/or acetate in a solution containing Cu precursor salt and metal M precursor salt, and mixing to obtain a mixed solution; or

Dissolving acetic acid and/or acetate, adding Cu precursor salt and metal M precursor salt, and mixing to obtain a mixed solution;

(2) carrying out solvent thermal reaction on the mixed solution obtained in the step (1), carrying out precipitation reaction, cooling, separating and collecting a solid phase;

(3) and (3) roasting the solid phase obtained in the step (2) in an aerobic environment to obtain the copper-based composite metal oxide mesomorphic microspheres.

The preparation method provided by the invention obtains the hollow core-shell structure copper-based composite metal oxide mesomorphic microspheres under the solvothermal environment for preparing the micro-nano material and by selecting proper reactant concentration, complexing agent and solvothermal reaction time and under the synergistic effect of thermodynamic and kinetic reasons. The preparation method provided by the invention has the advantages of simple process, mild conditions, no use of surfactant or polymer, environmental friendliness, good reproducibility, suitability for large-scale production and universality.

Preferably, the preparation method of the salt solution containing the Cu precursor salt and the metal M precursor salt in the step (1) includes: and dissolving and mixing the Cu precursor salt and the metal M precursor salt to obtain a salt solution.

Preferably, the solvent of the mixed solution includes any one or a combination of at least two or more of N, N-dimethylformamide, ethylenediamine or oleylamine, wherein the typical but non-limiting combination is: n, N-dimethylformamide and ethylenediamine, ethylenediamine and oleylamine, N-dimethylformamide, ethylenediamine and oleylamine.

Preferably, the Cu precursor salt and the metal M precursor salt each independently comprise any one of or a combination of at least two of a nitrate, oxalate, chloride or sulphate salt or bromide salt, with typical but non-limiting combinations: the Cu precursor salt is copper nitrate and the M precursor salt is lead sulfate, the Cu precursor salt is a combination of copper chloride and copper sulfate and the M precursor salt is a combination of tin nitrate and germanium chloride.

Preferably, the acetate salt comprises any one of ammonium acetate, sodium acetate or potassium acetate, or a combination of at least two thereof, with typical but non-limiting combinations: ammonium and sodium acetate, ammonium and potassium acetate, ammonium, sodium and potassium acetate.

Preferably, the concentration of the Cu precursor salt in the salt solution in step (1) is 0.002 to 0.07mol/L, for example, 0.002mol/L, 0.004mol/L, 0.008mol/L, 0.01mol/L, 0.015mol/L, 0.02mol/L, 0.025mol/L, 0.03mol/L, 0.035mol/L, 0.04mol/L, 0.045mol/L, 0.05mol/L, 0.055mol/L, 0.06mol/L, 0.065mol/L, or 0.07mol/L, and the like, and the concentration of the Cu precursor salt is higher than 0.07mol/L to obtain a polycrystalline material, but not a mesomorphic structure, and no product is generated when the concentration of the Cu precursor salt is lower than 0.002mol/L, preferably 0.02 to 0.05 mol/L.

Preferably, the molar volume ratio of the added acetic acid and/or acetate to the solvent is 0.07mol/L or more, for example, 0.07mol/L, 0.08mol/L, 0.1mol/L, 0.12mol/L, 0.15mol/L, 0.2mol/L, 0.25mol/L, 0.3mol/L, 0.35mol/L, 0.4mol/L, 0.5mol/L, 0.6mol/L, 0.8mol/L, 1.0mol/L, 1.2mol/L, 1.3mol/L, 1.4mol/L, 1.5mol/L, 1.6mol/L, or 1.8mol/L, etc., the acetic acid and acetate which is both a precipitant and a mesogenic structure-directing agent capable of adsorbing on the surface of the nanocrystals to prevent aggregation, the molar volume ratio of the acetic acid and/or acetate to the solvent being less than 0.07mol/L, almost no precipitation of the product is obtained, preferably 0.07 to 1.4 mol/L.

Preferably, the molar ratio of Cu in the Cu precursor salt to M in the metal M precursor salt is (1-100):1, and may be, for example, 1:1, 2:1, 5:1, 10:1, 12:1, 15:1, 20:1, 22:1, 25:1, 30:1, 33:1, 35:1, 40:1, 42:1, 45:1, 50:1, 52:1, 55:1, 60:1, 63:1, 65:1, 70:1, 72:1, 75:1, 80:1, 83:1, 85:1, 87:1, 90:1, 92:1, 95:1, 98:1, or 100:1, etc., and the molar ratio of Cu in the Cu precursor salt to M in the metal M precursor salt is capable of forming a dispersed and uniform nanoparticle composite, preferably (5-20): 1.

Preferably, the mixing means comprises stirring.

Preferably, the dissolving time is 0.05 to 24 hours, for example, 0.05 hour, 0.1 hour, 0.2 hour, 0.5 hour, 0.8 hour, 1 hour, 1.5 hour, 2 hour, 2.5 hour, 3 hour, 3.5 hour, 4 hour, 4.5 hour, 5 hour, 5.5 hour, 6 hour, 6.5 hour, 7 hour, 7.5 hour, 8 hour, 8.5 hour, 9 hour, 9.5 hour, 10 hour, 10.5 hour, 11 hour, 11.5 hour, 12 hour, 12.5 hour, 13 hour, 13.5 hour, 14 hour, 14.5 hour, 15 hour, 16 hour, 17 hour, 18 hour, 20 hour, 21 hour, 22 hour, 22.5 hour, 23 hour, 23.5 hour or 24 hour, etc., and the dissolving time can sufficiently dissolve and mix the solid substances to facilitate the subsequent uniform reaction to form a product of the components, preferably 0.1 to 24 hours.

Preferably, the temperature of the solvothermal reaction in the step (2) is 130-220 ℃, for example, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃, 210 ℃, 215 ℃ or 220 ℃ and the like, and the reaction temperature can obtain mesomorphic microspheres with uniform size and morphology, preferably 140-160 ℃.

Preferably, the solvothermal reaction time is 3 to 30 hours, for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 13 hours, 15 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, 25 hours, 27 hours, 28 hours, 29 hours or 30 hours, and the like, and the reaction time can change the surface topography of the product, preferably 6 to 14 hours.

Preferably, the cooling means comprises natural cooling and/or cooling in a cooling liquid.

Preferably, the cooling temperature is 20-60 deg.C, such as 20 deg.C, 25 deg.C, 30 deg.C, 35 deg.C, 40 deg.C, 45 deg.C, 50 deg.C, 55 deg.C or 60 deg.C, which can make the solid product completely precipitate, preferably 30-40 deg.C.

Preferably, the means of separation comprises any one or a combination of at least two of filtration, suction filtration or centrifugation, with typical but non-limiting combinations: firstly centrifuging and then filtering, and firstly centrifuging and then filtering.

Preferably, the oxygen-containing atmosphere in step (3) comprises oxygen and/or air.

Preferably, the roasting temperature is 150-.

Preferably, the calcination time is 1 to 24 hours, and may be, for example, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 7.5 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 14 hours, 15 hours, 16 hours, 18 hours, 20 hours, 21 hours, 22 hours, 23 hours, 23.5 hours, or 24 hours, etc., which enables the production of a uniform hollow core-shell structure, preferably 2 to 8 hours.

Preferably, the solid phase in step (3) is washed and dried, and then calcined in an oxygen-containing atmosphere.

Preferably, the wash liquor used for the washing comprises any one of water, ethanol or acetone, or a combination of at least two thereof, with typical but non-limiting combinations: water and ethanol, water, ethanol and acetone.

The water used in the present invention is not particularly limited, and may be distilled water or ultrapure water, and the present invention is applicable to any type commonly used by those skilled in the art.

Preferably, the number of washing is 3 or more, preferably 3 to 4.

Preferably, the drying means comprises any one or a combination of at least two of forced air drying, vacuum drying or freeze drying.

Preferably, the drying temperature is 50-150 ℃, for example, 50 ℃, 52 ℃, 55 ℃, 58 ℃, 60 ℃, 62 ℃, 65 ℃, 68 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 92 ℃, 95 ℃, 98 ℃, 100 ℃, 105 ℃, 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃, 142 ℃, 145 ℃, 148 ℃ or 150 ℃, the drying temperature can make the solvent completely volatile, preferably 60-100 ℃.

Preferably, the drying time is 6 to 30 hours, for example, 6 hours, 6.5 hours, 7 hours, 7.5 hours, 8 hours, 8.5 hours, 9 hours, 9.5 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 14.5 hours, 15 hours, 15.5 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 28.5 hours, 29 hours, 29.5 hours or 30 hours, etc., and the drying time can completely volatilize the solvent, preferably 9 to 15 hours.

Preferably, the preparation method comprises the following steps:

(1) dissolving acetic acid and/or acetate in a solution containing Cu precursor salt and metal M precursor salt, and stirring for 0.05-24h for mixing to obtain a mixed solution; or

Dissolving acetic acid and/or acetate in a solvent, adding a Cu precursor salt and a metal M precursor salt, and stirring and mixing for 0.05-24h to obtain a mixed solution;

the solvent of the mixed solution comprises any one or the combination of at least two of N, N-dimethylformamide, ethylenediamine or oleylamine;

the acetate comprises any one or the combination of at least two of ammonium acetate, sodium acetate or potassium acetate;

the molar volume ratio of the added acetic acid and/or acetate to the solvent is more than or equal to 0.07 mol/L;

the Cu precursor salt and the metal M precursor salt are respectively and independently selected from any one or a combination of at least two of nitrate, oxalate, chloride or sulfate or bromide; controlling the concentration of Cu precursor salt in the salt solution to be 0.002-0.07mol/L, wherein the molar ratio of Cu in the Cu precursor salt to M in the metal M precursor salt is (1-100): 1;

(2) carrying out solvothermal reaction on the mixed solution obtained in the step (1) at the temperature of 130-220 ℃ for 3-10h to generate precipitation reaction, cooling to 20-60 ℃, separating, and collecting a solid phase;

the separation mode comprises any one or the combination of at least two of filtration, suction filtration and centrifugation;

(3) and (3) washing the solid phase obtained in the step (2), drying at 50-150 ℃ for 6-30h, and then roasting at 900 ℃ for 1-24h in an aerobic environment to obtain the copper-based composite metal oxide mesomorphic microsphere.

In a third aspect, the invention provides a catalyst for a solar crystalline silicon raw material trichlorosilane synthesis reaction, wherein the catalyst adopts the copper-based composite metal oxide mesomorphic microspheres of the first aspect.

The mesomorphic microsphere has a hollow core-shell structure, and comprises a core, a gap and a shell from inside to outside in sequence, wherein the core and the shell are respectively composed of nano particles with consistent orientation, the nano particles comprise copper oxide nano particles and oxide nano particles of metal M, and in the trichlorosilane synthesis reaction, reaction phase HCl enters the gap through a shell pore passage of the shell and is fully contacted with the core; the inner core also has a mesoporous structure, has a larger contact area with the reaction phase, provides more active sites for the reaction phase, and can promote the adsorption and activation of reactants, so that the selectivity of trichlorosilane is up to more than 95.0%.

Compared with the prior art, the invention has the beneficial effects that:

(1) the copper-based composite metal oxide mesomorphic microsphere provided by the invention is formed by arranging nano particles with consistent orientation, has a unique hollow core-shell structure, contains various metal oxides as components, and is a catalyst with great potential. When the catalyst is used as a catalyst for a solar crystalline silicon raw material trichlorosilane synthesis reaction, the selectivity of trichlorosilane is over 95.0 percent, and the selectivity can reach 98.0 percent by optimizing preparation conditions;

(2) the preparation method has the advantages of simple process, mild conditions, no surfactant, low cost, environmental friendliness, good reproducibility and universality, and is suitable for large-scale production.

Drawings

FIG. 1 is an XRD pattern of a binary mesogenic material CuO-ZnO prepared in example 1;

FIG. 2(a) is a low magnification SEM image of the binary mesogenic material CuO-ZnO prepared in example 1; FIG. 2(b) is a high magnification SEM image of the binary mesogenic material CuO-ZnO prepared in example 1; FIG. 2(c) is a high magnification SEM image of the internal structure of the binary mesogenic material CuO-ZnO prepared in example 1;

FIG. 3 is a TEM image of a sample section obtained by FIB treatment of the binary mesogenic material CuO-ZnO prepared in example 1;

FIG. 4 is a HRTEM image of the binary mesogenic material CuO-ZnO prepared in example 1;

FIGS. 5(a) -5 (d) are BF-STEM diagrams and surface scanning distribution diagrams of the elements Cu, Zn and O, respectively, of the binary mesogenic material CuO-ZnO prepared in example 1;

FIG. 6 shows the ternary mesogenic material In prepared In example 8₂O₃-XRD pattern of ZnO-CuO;

FIG. 7(a) shows the ternary mesogenic material In prepared In example 8₂O₃-low magnification SEM image of ZnO-CuO; FIG. 7(b) is the ternary mesogenic material In prepared In example 8₂O₃-high magnification SEM image of ZnO-CuO; FIG. 7(c) shows In as a ternary mesogenic material prepared In example 8₂O₃High internal structure of-ZnO-CuOMagnification SEM picture;

FIG. 8 shows the ternary mesogenic material In prepared In example 8₂O₃TEM image of FIB-treated sample section of-ZnO-CuO;

FIG. 9 shows the ternary mesogenic material In prepared In example 8₂O₃HRTEM image of-ZnO-CuO;

FIGS. 10(a) to 10(e) are diagrams illustrating In ternary mesogenic materials prepared In example 8₂O₃-BF-STEM plot of ZnO-CuO and area scan profile of elements Cu, Zn, In and O;

FIG. 11 shows ternary micron In prepared In comparative example 6₂O₃SEM picture of-ZnO-CuO;

FIG. 12 is the XRD pattern of the waste contacts after the catalytic reaction of example 8;

FIG. 13 is an enlarged plot of XRD of the waste contacts at 40-50 ℃ after the catalytic reaction of example 8.

Detailed Description

The technical solution of the present invention will be further described with reference to the following embodiments. It should be understood by those skilled in the art that the examples described are only for the purpose of facilitating understanding of the present invention and should not be construed as specifically limiting the present invention.

The hollow core-shell structure copper-based composite metal oxide mesomorphic microspheres prepared in the embodiments and the comparative examples of the invention are tested by the following method:

XRD testing was performed on an X' Pert PRO MPD model multifunction X-ray diffractometer manufactured by Panalytical corporation (Pasacaceae) in the Netherlands; observing the surface appearance of the sample on a JSM-7001F scanning electron microscope manufactured by JEOL company of Japan; observing the internal structure thereof on a transmission electron microscope of JEM-2010F model manufactured by JEOL corporation of Japan; the element distribution was tested on an INCAX-MAX type spectrometer manufactured by Oxford corporation, England; ICP testing was performed on a Pekin-Elmer inductively coupled plasma atomic emission spectrometer, USA.