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CN-119708529-B - Two-dimensional amorphous copper-based MOF material and preparation method and application thereof

CN119708529BCN 119708529 BCN119708529 BCN 119708529BCN-119708529-B

Abstract

The invention provides a two-dimensional amorphous copper-based MOF material, and a preparation method and application thereof. The preparation method comprises the following steps of reacting a mixed solution of an organic ligand, copper salt and an organic solvent in a closed environment to obtain the two-dimensional amorphous copper-based MOF material. The preparation method provided by the invention can directly synthesize the two-dimensional amorphous MOF material in one step without secondary treatment, and is different from the preparation method which is commonly adopted at present and used for inducing crystal collapse by hydrostatic pressure, heating, mechanical stress, radiation, discharge and the like. Meanwhile, the catalyst obtained by the two-dimensional amorphous MOF material is used for electrocatalytic CO 2 reduction, can effectively increase the selectivity of C 2+ products including ethylene and ethanol, and shows excellent catalytic activity. In addition, the preparation process is simple to operate, the conditions are easy to control, the applicability is wide, and the yield is high.

Inventors

  • ZHOU MIN
  • LI YUELIN

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260505
Application Date
20250107

Claims (8)

  1. 1. The preparation method of the two-dimensional amorphous copper-based MOF material is characterized by comprising the following steps of: reacting a mixed solution of an organic ligand, copper salt and an organic solvent in a closed environment to obtain a two-dimensional amorphous copper-based MOF material; the organic ligand is selected from any one or more of 2-hydroxy terephthalic acid, 2, 3-dihydroxybenzoic acid, 2, 3-dihydroxyterephthalic acid, 2, 5-dihydroxybenzoic acid, 2, 6-dihydroxybenzoic acid, 4-hydroxybenzoic acid or p-hydroxybenzoic acid; The molar ratio of copper in the copper salt to the organic ligand is 4:1-1:13; The organic solvent is a mixed solvent of N, N-dimethylformamide and acetonitrile, and the volume ratio of the N, N-dimethylformamide to the acetonitrile is 5:1-1:11; the mixed solution of the organic ligand, copper salt and organic solvent is obtained by dissolving the organic ligand and copper salt in the organic solvent; The dissolution is carried out at a rotation speed of 50-1400 rpm; The pH value of the mixed solution is 1-6.7; The reaction is heated to 80-120 ℃ according to the speed of 2-20 ℃ min -1 ; the reaction has a heat preservation time of 24-48 h at 80-120 ℃.
  2. 2. The preparation method according to claim 1, wherein the copper salt is selected from any one or more of Cu(NO 3 ) 2 、Cu(NO 3 ) 2 •3H 2 O、CuSO 4 、CuSO 4 •5H 2 O、CuCl 2 、CuCl 2 •2H 2 O、CuCrO 4 •2H 2 O or CuCr 2 O 7 •2H 2 O.
  3. 3. The preparation method according to claim 1 or 2, characterized in that the molar ratio of copper in the copper salt to organic ligand is 4:1-1:8.
  4. 4. The preparation method of claim 1, wherein the volume ratio of the N, N-dimethylformamide to the acetonitrile is 3:1-1:6.
  5. 5. The method of claim 1, further comprising the steps of washing and drying after the reaction.
  6. 6. The two-dimensional amorphous copper-based MOF material prepared by the preparation method according to any one of claims 1-5, wherein the two-dimensional amorphous copper-based MOF material has a two-dimensional nano-sheet structure.
  7. 7. The two-dimensional amorphous copper-based MOF material prepared by the preparation method of any one of claims 1-5 or the application of the two-dimensional amorphous copper-based MOF material in electrocatalytic CO 2 reduction.
  8. 8. The use according to claim 7, wherein in the electrocatalytic CO 2 reduction, the working electrode comprises the two-dimensional amorphous copper-based MOF material prepared by the preparation method according to any one of claims 1 to 5 or the two-dimensional amorphous copper-based MOF material according to claim 6.

Description

Two-dimensional amorphous copper-based MOF material and preparation method and application thereof Technical Field The invention belongs to the technical field of metal organic complexes, and particularly relates to a two-dimensional amorphous copper-based MOF material, and a preparation method and application thereof. Background In recent years, with the continuous progress of industrial civilization, the massive consumption of fossil fuels has not only raised energy crisis, but also resulted in massive carbon dioxide emissions, exacerbating environmental problems such as greenhouse effect and global warming. Currently, since materials that completely replace fossil fuels cannot be found in a short period of time, there is a need to develop efficient, stable, and viable carbon dioxide conversion technologies to reduce carbon dioxide emissions. It has been reported that copper-based catalysts can electrocatalytically reduce CO 2 to a variety of chemical products with wide applications under mild conditions. The multi-carbon products such as ethylene, ethanol and the like obtained by reduction have higher economic value and energy density, but have the difficulties and challenges of wide product distribution, low selectivity of C 2+ products and the like. Therefore, optimizing copper-based catalysts is particularly critical for improving product selectivity and improving product distribution. The Metal-organic framework Material (MOF) is a material which is formed by self-assembly of Metal-organic ligands and Metal ions through Metal-ligand complexation and has a periodic porous network structure, and has the characteristics of adjustable pore structure, large specific surface area, stable chemical property and the like, so that the Metal-organic framework material has wide application in the fields of catalysis, medical materials, energy storage and the like. The amorphous MOF material has the common characteristics of the crystalline MOF material, including excellent thermal stability, high surface area, high porosity and adjustable pore structure, and has the special advantages of the amorphous material, such as isotropy, no grain boundary structure, abundant defects, active sites and the like. Thus, amorphous MOF materials exhibit superior performance in the catalytic field compared to crystalline MOF materials. Currently, most amorphous MOF materials are prepared by stressing the crystalline framework. Physical treatments such as hydrostatic and hydrostatic pressure, heating, mechanical stress (ball milling, grinding, etc.), radiation and electrical discharge have all been applied to crystalline MOF materials to induce collapse of their crystal structure, and in addition, chemical treatments by amorphization can also lead to crystal failure. However, the above preparation method is complicated in process, and it is generally necessary to prepare a crystalline MOF material by a solvothermal method and then subject the crystalline MOF to a secondary treatment to amorphize the crystalline MOF material. Meanwhile, the difficulty of the secondary treatment process is high, and special instruments and equipment are needed for operation in most cases. For example, hydrostatic pressure treatment requires placing the crystalline MOF powder in a Diamond Anvil Cell (DAC) and using pressureless fluid or methanol-ethanol-water (MEW) isopropanol or perfluoro-tripentylamine (FC-70) to mediate compression of the sample, while amorphization treatments such as ball milling, grinding, etc. provide less mechanical stress, are difficult to break the crystal structure, take up to several weeks, and are less efficient. Disclosure of Invention In view of the above, the invention aims to provide a two-dimensional amorphous copper-based MOF material, and a preparation method and application thereof. The preparation method can directly synthesize the amorphous MOF material by a one-step method, does not need secondary treatment, and is simple, convenient and high in efficiency. In order to achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the invention provides a method for preparing a two-dimensional amorphous copper-based MOF material, comprising the following steps: reacting a mixed solution of an organic ligand, copper salt and an organic solvent in a closed environment to obtain a two-dimensional amorphous copper-based MOF material; Preferably, the organic ligand is selected from any one or more of 2-hydroxy terephthalic acid, 2, 3-dihydroxybenzoic acid, 2, 3-dihydroxyterephthalic acid, 2, 5-dihydroxybenzoic acid, 2, 6-dihydroxybenzoic acid, 4-hydroxybenzoic acid, or p-hydroxybenzoic acid. Preferably, the organic solvent is a mixed solvent of N, N-dimethylformamide and acetonitrile, and the volume ratio of the N, N-dimethylformamide to the acetonitrile is 5:1-1:11. Preferably, the copper salt is selected from any one or more of Cu(NO3)2、Cu(NO3)2•3H2O、CuSO4、CuSO4•5H2O、CuCl2、CuCl2•2H2