A method for preparing a coral-like CuO / Ag catalyst

Abstract

The present application relates to the technical field of silanol preparation, and discloses a preparation method of a coral-like CuO / Ag catalyst, comprising the following steps: S1, mixing a copper source and a polymer surfactant, and then adding an amine source to prepare a mixed initial solution A; S2, placing a structure directing agent in ionized water and mixing the structure directing agent with the mixed initial solution A to obtain a mixed initial solution B; S3, heating the mixed initial solution B, adding a silver source, and stirring to obtain a product initial solution; and S4, centrifuging, washing, drying, and grinding the product initial solution to obtain the coral-like CuO / Ag catalyst. The catalyst is convenient to prepare and produce, is convenient for large-scale industrial synthesis, saves cost, and improves production and synthesis efficiency. The catalyst is low in price, the preparation method is simple, raw materials are easy to obtain, and the catalyst has the advantages of small catalyst dosage, wide substrate range, mild reaction conditions, simple operation, green environmental protection, short reaction time, high yield, and good selectivity.

Description

Technical Field

[0001] This invention relates to the field of silanol preparation technology, and in particular to a method for preparing a coral-like CuO / Ag catalyst. Background Technology

[0002] The green oxidation of silanes to prepare silanols is one of the most important transformations in organic synthesis, providing key intermediates for the synthesis of promising pesticides, pharmaceuticals, bioisosteres, optically active materials, heat-resistant functional materials, and other fine chemicals. Although organosilanes can produce the corresponding products under the action of strong oxidants such as acidic potassium permanganate, dioxane, osmium tetroxide, ozone, and oxazolidine, the condensation or decomposition of silanols, the generation of byproducts, and the low yields are all challenges. While there is a great demand and industrial potential for efficient silane-catalyzed methods to practically obtain high-value silanol molecules, significant challenges remain.

[0003] Recently, efforts have been focused on utilizing solar energy to develop green catalytic oxidation of silanes to silanols, an environmentally friendly method based on using oxygen, water, or hydrogen peroxide as oxidants. However, most research has concentrated on preparing noble metal catalysts for efficient silane oxidation. Although noble metal catalysts exhibit excellent activity, the limited supply and high cost of noble metals restrict their sustainable development. Therefore, the use of relatively abundant and low-cost non-noble metal materials to catalyze silane oxidation reactions has attracted widespread attention. However, non-noble metal catalysts often require more stringent reaction conditions and exhibit relatively poor catalytic performance. Therefore, there is a need to find a more economical, readily available, efficient, and inexpensive catalyst to achieve highly active silanol production. Summary of the Invention

[0004] To address the existing technical problems, this invention provides a method for preparing a coral-like CuO / Ag catalyst.

[0005] This invention is achieved using the following technical solution: a method for preparing a coral-like CuO / Ag catalyst, comprising the following steps:

[0006] S1 involves mixing a copper source with a polymeric surfactant, and then adding an amine source to prepare a mixed initial solution A;

[0007] S2 places the structure-directing agent in deionized water and mixes it with the initial mixed solution A to obtain the initial mixed solution B;

[0008] S3 heats the initial mixed solution B and adds a silver source, stirring and mixing to generate the initial product solution;

[0009] S4 centrifuges, washes, dries, and grinds the initial product liquid to obtain a coral-like CuO / Ag catalyst.

[0010] As a further improvement to the above scheme, the copper source is at least one of copper acetate, copper sulfate, copper nitrate, copper chloride, cuprous chloride, and copper acetylacetonate.

[0011] As a further improvement to the above scheme, the amine source is at least one of trioctylamine, oleylamine, acetamide, melamine, hexamethylenetetramine, acrylamide, hydroxylamine hydrochloride, N,N-dimethylformamide hexadecylamine, octadecylamine, ethylenediamine, tetrabutylammonium hydroxide, n-butylamine, tetramethylammonium bromide, ethylenediaminetetraacetic acid, and ammonium acetate.

[0012] As a further improvement to the above scheme, the structure directing agent is at least one of potassium sulfate, sodium nitrate, sodium monohydrogen phosphate, sodium phosphate, potassium iodide, potassium iodate, sodium bromide, sodium fluoride, and sodium chloride.

[0013] As a further improvement to the above scheme, the polymeric surfactant is at least one of polyvinylpyrrolidone, polysorbate, polyoxyethylene methacrylate, polyoxyethylene styrene, sodium polyacrylate solution, sodium polymethacrylate and its derivatives, disodium salt of maleic anhydride diisobutylene copolymer, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0014] As a further improvement to the above scheme, the silver source is at least one of silver nitrate, silver acetate, and silver nanoparticles, and the mass ratio of silver in the copper source, surfactant, amine source, structure directing agent, and silver source is 39.6-400:60-1000:2-30:10-200.

[0015] As a further improvement to the above scheme, the molecular weight of the polyvinylpyrrolidone is at least one of 55,000, 1,300,000, and 29,000.

[0016] A product for the photocatalytic oxidation of silanols, said product being a coral-like CuO / Ag catalyst.

[0017] A method for preparing silanol by photocatalytic oxidation includes the following steps:

[0018] Coral-like CuO / Ag catalyst and silane substrate were dispersed in a reaction solvent and subjected to selective catalytic oxidation under xenon lamp irradiation to prepare silanol.

[0019] The silane substrate has the following structural formula:

[0020]

[0021] In the formula, R1, R2, and R3 are any one of hydrogen, alkyl, and phenyl.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The catalyst of the present invention is easy to prepare and produce, facilitates large-scale industrial synthesis, saves costs and improves production efficiency;

[0024] 2. The catalyst used in this invention is inexpensive, the preparation method is simple, the raw materials are readily available, and it has the advantages of low catalyst dosage, wide substrate range, mild reaction conditions, simple operation, green and environmentally friendly, short reaction time, high yield, and good selectivity. Attached Figure Description

[0025] Figure 1 X-ray diffraction (XRD) patterns of CuO / Ag and commercial CuO catalysts in Example 4 of this invention;

[0026] Figure 2 X-ray electron spectra of the CuO / Ag catalyst in Example 4 of this invention;

[0027] Figure 3 Raman spectroscopy of the CuO / Ag catalyst in Example 4 of this invention;

[0028] Figure 4 Scanning electron microscope (SEM) image of the commercial CuO catalyst and transmission electron microscope (TEM) image of the CuO / Ag catalyst in Example 4 provided by the present invention;

[0029] Figure 5 The effect diagram of the catalytic oxidation of silane to silanol by commercial CuO catalyst and CuO / Ag catalyst in Example 5 of the present invention;

[0030] Figure 6 The stability diagram of CuO / Ag catalytic performance in Example 5 provided by the present invention. Detailed Implementation

[0031] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0032] Example 1

[0033] This embodiment describes a method for preparing a coral-like CuO / Ag catalyst, comprising the following steps:

[0034] S1 involves mixing a copper source with a polymeric surfactant, and then adding an amine source to prepare a mixed initial solution A;

[0035] S2 places the structure-directing agent in deionized water and mixes it with the initial mixed solution A to obtain the initial mixed solution B;

[0036] S3 heats the initial mixed solution B and adds a silver source, stirring and mixing to generate the initial product solution;

[0037] S4 centrifuges, washes, dries, and grinds the initial product liquid to obtain a coral-like CuO / Ag catalyst.

[0038] The copper source is at least one of copper acetate, copper sulfate, copper nitrate, copper chloride, cuprous chloride, and copper acetylacetonate.

[0039] The amine source is at least one of the following: trioctylamine, oleylamine, acetamide, melamine, hexamethylenetetramine, acrylamide, hydroxylamine hydrochloride, N,N-dimethylformamide hexadecylamine, octadecylamine, ethylenediamine, tetrabutylammonium hydroxide, n-butylamine, tetramethylammonium bromide, ethylenediaminetetraacetic acid, and ammonium acetate.

[0040] The structure directing agent is at least one of potassium sulfate, sodium nitrate, sodium monohydrogen phosphate, sodium phosphate, potassium iodide, potassium iodate, sodium bromide, sodium fluoride, and sodium chloride.

[0041] The polymeric surfactant is at least one of the following: polyvinylpyrrolidone, polysorbate, polyoxyethylene methacrylate, polyoxyethylene styrene, sodium polyacrylate solution, sodium polymethacrylate and its derivatives, disodium salt of maleic anhydride diisobutylene copolymer, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0042] The silver source is at least one of silver nitrate, silver acetate, or silver nanoparticles. The mass ratio of silver in the copper source, surfactant, amine source, structure directing agent, and silver source is 39.6-400:60-1000:2-30:10-200.

[0043] The molecular weight of polyvinylpyrrolidone is at least one of 55,000, 1,300,000, or 29,000.

[0044] Example 2

[0045] A product for the photocatalytic oxidation of silanols, the product being a coral-like CuO / Ag catalyst.

[0046] Example 3

[0047] A method for preparing silanol by photocatalytic oxidation includes the following steps:

[0048] Coral-like CuO / Ag catalyst and silane substrate were dispersed in a reaction solvent and subjected to selective catalytic oxidation under xenon lamp irradiation to prepare silanol.

[0049] The structural formula of the silane substrate is as follows:

[0050]

[0051] In the formula, R1, R2, and R3 are any one of hydrogen, alkyl, and phenyl.

[0052] Example 4

[0053] like Figures 1-4 As shown, a method for preparing a coral-like CuO / Ag catalyst includes the following steps:

[0054] In a 100 mL three-necked flask, add sequentially 39.6-400 mg of copper acetate or copper sulfate, copper nitrate, copper chloride, cuprous chloride, copper acetylacetonate, 160-1000 mg of polyvinylpyrrolidone or polysorbate, polyoxyethylene methacrylate, polyvinyl styrene oxide, sodium polyacrylate solution, sodium polymethacrylate and its derivatives, disodium salt of maleic anhydride diisobutylene copolymer, and alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether as surfactants, 10-25 mL of N,N-dimethylformamide or oleylamine, acetamide, n-butylamine, melamine, hexamethylenetetramine, acrylamide, trioctylamine, hexadecylamine, octadecylamine, ethylenediamine, tetrabutylammonium hydroxide, tetramethylammonium bromide, ethylenediaminetetraacetic acid, ammonium acetate; then dissolve 10-200 mg of potassium iodide or potassium iodate, sodium bromide, sodium fluoride, and sodium chloride solid in deionized water, and mix the two; heat in an oil bath or metal bath, and when the temperature rises to 150-180°C, add 0.01-2 mL of silver particle sol with a particle size of 5-200 nanometers (2-30 mg of silver nanometers), and reflux the reaction under magnetic stirring for 1 h, and the color of the dispersion gradually changes from green to black;

[0055] The molecular weight of polyvinylpyrrolidone is any one of 55,000, 1,300,000, or 29,000.

[0056] (2) Cool the solution obtained in step (1) to room temperature, centrifuge to collect the catalyst, wash it several times with water or ethanol or acetone, dry it in a vacuum drying oven at 80°C, grind the dried sample to obtain black powdered copper silver oxide catalyst.

[0057] Example 5

[0058] like Figures 5-6 As shown, a method for preparing silanol by photocatalytic oxidation includes the following steps: 2-20 mg of coral-like CuO / Ag catalyst, 75 μL of dimethylphenylsilane, 1 mL of methanol or ethanol, isopropanol, dichloromethane, tetrahydrofuran, acetonitrile, acetone, 1,4-dioxane, dimethyl ether, and 500 μL of H2O2 (30 wt%) are added to a quartz reactor. Under xenon lamp irradiation and vigorous stirring, samples are taken at regular intervals, and the contents of silane and silanol are determined by high-performance gas chromatography.

[0059] The catalyst of this invention is easy to prepare and produce, facilitates large-scale industrial synthesis, saves costs and improves production efficiency.

[0060] The catalyst used is inexpensive, the preparation method is simple, the raw materials are readily available, and it has the advantages of low catalyst dosage, broad substrate range, mild reaction conditions, simple operation, green and environmentally friendly, short reaction time, high yield, and good selectivity.

[0061] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a coral-like CuO / Ag catalyst, characterized in that, The process includes the following steps: S1. A copper source is mixed with a polymeric surfactant, and then an amine source is added to prepare a mixed initial solution A; The copper source is at least one of copper acetate, copper sulfate, copper nitrate, copper chloride, cuprous chloride, and copper acetylacetonate. The amine source is at least one of the following: trioctylamine, oleylamine, acetamide, melamine, hexamethylenetetramine, acrylamide, hydroxylamine hydrochloride, N,N-dimethylformamide hexadecylamine, octadecylamine, ethylenediamine, tetrabutylammonium hydroxide, n-butylamine, tetramethylammonium bromide, ethylenediaminetetraacetic acid, and ammonium acetate; The polymeric surfactant is at least one of the following: polyvinylpyrrolidone, polysorbate, polyoxyethylene methacrylate, polyoxyethylene styrene, sodium polyacrylate solution, sodium polymethacrylate and its derivatives, disodium salt of maleic anhydride diisobutylene copolymer, and alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether. S2 places the structure-directing agent in deionized water and mixes it with the initial mixed solution A to obtain the initial mixed solution B; The structure directing agent is at least one of potassium sulfate, sodium nitrate, sodium monohydrogen phosphate, sodium phosphate, potassium iodide, potassium iodate, sodium bromide, sodium fluoride, and sodium chloride. S3 heats the initial mixed solution B and adds a silver source, stirring and mixing to generate the initial product solution; Among them, the silver source is at least one of silver nitrate, silver acetate, and silver nanoparticles; S4 centrifuges, washes, dries, and grinds the initial product liquid to obtain a coral-like CuO / Ag catalyst.

2. The method for preparing a coral-like CuO / Ag catalyst as described in claim 1, characterized in that, The molecular weight of the polyvinylpyrrolidone is at least one of 55,000, 1,300,000, and 29,000.

3. A catalyst for the photocatalytic oxidation of silanols, characterized in that, The catalyst is a coral-like CuO / Ag catalyst prepared by the method described in any one of claims 1-2.

4. A method for preparing silanols by photocatalytic oxidation, characterized in that, Includes the following steps: The coral-like CuO / Ag catalyst of claim 3 is dispersed with a silane substrate in a reaction solvent and subjected to selective catalytic oxidation under xenon lamp irradiation to obtain silanol.

5. The method for preparing silanol by photocatalytic oxidation as described in claim 4, characterized in that, The silane substrate has the following structural formula: ； In the formula, R1, R2, and R3 are any one of hydrogen, alkyl, and phenyl.

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