CN-121975145-A - 2-X-terephthalic acid copper-based MOFs micro-nano sheet and preparation method and application thereof

Abstract

The invention discloses a 2-x-terephthalic acid copper-based MOFs micro-nano sheet and a preparation method and application thereof, wherein the method comprises the following steps: dropwise adding a copper chloride dihydrate solution into a pre-deprotonated 2-x-terephthalic acid solution, stirring for reaction, centrifugally washing and drying a product to obtain the 2-x-terephthalic acid copper-based MOFs micro-nano sheet, wherein x is one of methyl, amino or hydroxyl. The 2-x-terephthalic acid copper-based MOFs micro-nano sheet can be used for electrocatalytic carbon dioxide reduction. The 2-x-terephthalic acid copper-based MOFs micro-nano sheet prepared by the method has a unique fold state sheet structure, the specific surface area and the exposure degree of active sites of the material are obviously increased, and the mass transfer and charge transfer paths are shortened, so that the catalytic reaction kinetics and the energy efficiency are integrally optimized.

Inventors

• WU YUCHENG
• HU FEI
• ZHOU WEI
• CUI JIEWU

Assignees

• 合肥工业大学

Dates

Publication Date

20260505

Application Date

20260408

Claims (10)

1. 1. The preparation method of the 2-x-copper terephthalate-based MOFs micro-nano sheet is characterized by comprising the following steps of dropwise adding a copper chloride dihydrate solution into a pre-deprotonated 2-x-terephthalic acid solution, stirring for reaction, centrifugally washing and drying a product, and obtaining the 2-x-copper terephthalate-based MOFs micro-nano sheet, wherein x is one of methyl, amino or hydroxyl.
2. 2. The method for preparing 2-x-terephthalic acid copper-based MOFs micro-nano sheets, according to claim 1, is characterized in that: The concentration of the copper chloride dihydrate solution is 0.02-0.2 mol/L; the concentration of the pre-deprotonated 2-x-terephthalic acid solution is 0.01-0.06 mol/L; The volume ratio of the copper chloride dihydrate solution to the pre-deprotonated 2-x-terephthalic acid solution is 1 (2-3); The temperature of the stirring reaction is room temperature, and the reaction time is 1-6 hours; the centrifugal washing is carried out by deionized water, and the times of the centrifugal washing are 2-3 times; The drying temperature is 60-80 ℃, and the drying time is 6-12 h.
3. 3. The method for preparing 2-x-terephthalic acid copper-based MOFs micro-nano plates according to claim 1, wherein the pre-deprotonated 2-x-terephthalic acid solution is obtained by adding 2-x-terephthalic acid ligand into deionized water solution of sodium hydroxide, and the ratio of the concentration of the sodium hydroxide solution to the concentration of the 2-x-terephthalic acid ligand is 2:1.
4. 4. A 2-x-terephthalic acid copper-based MOFs micro-nano sheet prepared by the preparation method of the 2-x-terephthalic acid copper-based MOFs micro-nano sheet according to any one of claims 1 to 3.
5. 5. The 2-x-copper terephthalate based MOFs micro-nano sheet according to claim 4, wherein when x is methyl, the 2-x-copper terephthalate based MOFs micro-nano sheet has a size of 0.3-3 μm and shows a lamellar structure with obvious macroporous characteristics and folds.
6. 6. The 2-x-copper terephthalate based MOFs micro-nano sheet according to claim 4, wherein when x is an amino group, the 2-x-copper terephthalate based MOFs micro-nano sheet has a size of 0.3-3 μm and is in a wrinkled continuous lamellar structure.
7. 7. The 2-x-copper terephthalate based MOFs micro-nano sheet according to claim 4, wherein when x is hydroxyl, the 2-x-copper terephthalate based MOFs micro-nano sheet has a size of 0.5-5 μm and is in a wrinkled continuous sheet structure.
8. 8. The application of the 2-x-terephthalic acid copper-based MOFs micro-nano sheet according to claim 4, wherein the 2-x-terephthalic acid copper-based MOFs micro-nano sheet is applied to electrocatalytic carbon dioxide reduction.
9. 9. A preparation method of a cathode of a flow battery is characterized by comprising the following steps of dispersing 2-x-copper terephthalate-based MOFs micro-nano sheets in a mixed solution of ethanol and water, preparing a suspension after ultrasonic dispersion, adding an adhesive to prepare a catalyst slurry, spraying the catalyst slurry on carbon paper, and drying the carbon paper loaded with the catalyst to obtain the cathode of the flow battery.
10. 10. The method for preparing a cathode for a flow battery according to claim 9, wherein: the volume ratio of the ethanol to the water is (4-9) 1; The mass ratio of the 2-x-terephthalic acid copper-based MOFs micro-nano sheet to the mixed solution of ethanol and water is 1 (1000-3000); The ultrasonic dispersion time is 10-30 min; The adhesive is naphthol adhesive; the loading capacity of the catalyst slurry on the carbon paper is 0.25-0.75 mg cm -2 ; the drying temperature is 60-80 ℃, and the drying time is 0.5-2 h.

Description

2-X-terephthalic acid copper-based MOFs micro-nano sheet and preparation method and application thereof Technical Field The invention relates to the technical field of synthesis of CO 2 reduction catalysts, in particular to a 2-x-terephthalic acid copper-based MOFs micro-nano sheet, a preparation method and application thereof. Background The development of efficient copper-based metal organic framework electrocatalyst for carbon dioxide reduction not only requires a green synthesis method with mild reaction conditions and controllable morphology, but also requires the realization of precise regulation and control of the electronic structure of materials to guide the selectivity of products. However, the synthesis of most of the existing copper-based MOFs (metal organic framework) materials depends on a high-temperature and high-pressure solvothermal method, and the method is high in energy consumption, complex in process, difficult to accurately regulate and control the microstructure and surface structure of the materials, so that the prepared materials are mostly three-dimensional blocks with low specific surface areas, poor in accessibility of active sites and high in mass transfer resistance, and the practical application of the prepared materials in electrocatalytic reactions is severely restricted. At present, the realization of the controllable construction of two-dimensional or open structures of copper-based MOFs under mild and green conditions still faces significant challenges. The conventional method often needs to introduce an organic solvent, a structure directing agent or harsh reaction conditions, has complex process and low environmental compatibility, and is difficult to balance between structure controllability and synthesis sustainability. In addition, how to effectively inhibit stacking, agglomeration or phase transformation to stable phase during synthesis and post-treatment of high surface energy nano-sheets, and maintain the surface characteristics of the high surface energy nano-sheets, which are open and high in activity, is also a main difficulty in the current preparation. The existing strategy often depends on surfactant or complex post-treatment, impurities are easy to introduce or structural integrity is easy to damage, and the activity and stability are difficult to be combined. On the other hand, on the basis of realizing controllable morphology, how to further systematically regulate and control the electronic structure of the material so as to precisely influence the interaction between the material and the CO 2 and the interaction between the material and the intermediate thereof, and further guide the specific reaction path and the product distribution, and a clear and extensible material design strategy is still lacking at present. Most of the current research is still focused on single ligand or mixed ligand systems, lacking fine electronic control through ligand substituents to precisely influence the adsorption behavior of key intermediates (such as * CO), thus effectively directing the CO 2 reduction pathway. Therefore, a series of synthesis strategies of copper-based MOF materials with definite preparation structure, stable morphology and adjustable electronic structure can be controlled under mild and green conditions, so that the method has important methodological significance, and provides a key material foundation for deep understanding of a catalytic mechanism and selective regulation of CO 2 RR (carbon dioxide reduction reaction). Disclosure of Invention The invention aims to provide a 2-x-terephthalic acid copper-based MOFs micro-nano sheet, a preparation method and application thereof, which can be used for preparing alkane (C xHy) or C 2+ products by electrocatalytic CO 2 reduction, and the material has the advantages of simple preparation method, low cost and wide application prospect. In one aspect of the invention, the invention provides a preparation method of 2-x-terephthalic acid copper-based MOFs micro-nano sheets. According to the embodiment of the invention, the method comprises the following steps of dropwise adding a copper chloride dihydrate solution into a pre-deprotonated 2-x-terephthalic acid solution, stirring for reaction, centrifugally washing and drying a product to obtain the 2-x-terephthalic acid copper-based MOFs micro-nano sheet, wherein x is one of methyl, amino or hydroxyl. According to the invention, different functional groups are accurately introduced on the benzene ring ligand, so that the cooperative regulation and control of the copper activity center electronic structure and the reaction microenvironment can be realized, and the selectivity of the CO 2 reduced product is guided in a directional manner. The amino group is taken as a strong electron donor, so that the electron density of the copper active center can be improved, and the d-band center position of the copper active center can be regulated, thereby effectively