CN-121992434-A - Preparation method of NiFeCe-DHDBC MOF composite catalyst and application of NiFeCe-DHDBC MOF composite catalyst in water electrolysis

Abstract

The invention relates to the technical field of catalysts, in particular to a preparation method of a NiFeCe-DHDBC MOF composite catalyst and application thereof in electrolyzed water, wherein the catalyst takes nickel salt, iron salt and cerium salt as metal sources, specific organic reagent as regulator, and (3) taking the mixed solution of DMF and deionized water as a reaction medium, and standing the foam nickel substrate in the mixed system for reaction to realize in-situ loading of NiFeCe-DHDBC MOF material on the surface of the foam nickel, thereby forming a composite catalytic system. The NiFeCe-DHDBC MOF material prepared by the invention shows OER catalytic activity obviously superior to that of the traditional nickel-iron-based catalyst and the pure foam nickel substrate in alkaline electrolyte by virtue of the synergistic effect among ternary metals, the unique advantage of MOF structure and good interface combination caused by in-situ load, has good operation stability in a high current density interval, is suitable for industrial application scenes of electrolytic water hydrogen production, provides a new technical path for developing the high-efficiency non-noble metal OER catalyst, has technical innovation and practical application value, and has wide industrialization prospect.

Inventors

• CHENG YU
• Ji Zengrui
• LIU HUIYU
• ZHANG RUKANG
• QIAN TAO

Assignees

• 南通大学

Dates

Publication Date

20260508

Application Date

20260311

Claims (9)

1. 1. The preparation method of NiFeCe-DHDBC MOF composite catalyst is characterized in that NiFeCe-DHDBC MOF material is in situ loaded on the surface of foam nickel to form a composite catalytic system, and the preparation method comprises the following steps: Step 1, preparing a precursor solution, namely sequentially adding a nickel salt, an iron salt and a cerium salt serving as metal sources and a mixed solution of DMF and deionized water serving as a reaction medium into the mixed medium by taking the organic reagent as a regulator, and stirring until the metal sources and the regulator are completely dissolved to obtain a uniform precursor solution; Step 2, foam nickel pretreatment, namely sequentially carrying out ultrasonic cleaning on the foam nickel, firstly cleaning the foam nickel with ethanol for 20-40min, then cleaning the foam nickel with acetone for 20-40min, then cleaning the foam nickel with 3-5 mol.L -1 hydrochloric acid solution for 10min for 3 times, and finally cleaning the foam nickel with deionized water for 30min for 4-5 times; Step 3, standing reaction, namely placing the foam nickel pretreated in the step 2 into the precursor solution prepared in the step 1, standing at normal temperature for 6-10 hours, and enabling NiFeCe-DHDBC MOF material to grow on the surface of the foam nickel in situ; and step 4, post-treatment, namely taking out a sample after the reaction is finished, and cleaning and drying to obtain the NiFeCe-DHDBC MOF foam nickel composite catalyst.
2. 2. The preparation method of NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 1, the nickel salt is selected from one or more of nickel nitrate, nickel chloride and nickel sulfate, the dosage is 3-5mmol, the iron salt is selected from one or more of ferric nitrate, ferric chloride and ferric sulfate, the dosage is 0.5-1.5mmol, the cerium salt is selected from one or more of cerium nitrate, cerium chloride and cerium sulfate, the dosage is 0.5-1.5mmol, and the molar ratio of nickel salt, iron salt and cerium salt is 4:1:1.
3. 3. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 1, the organic reagent is triethylamine, and the concentration of the organic reagent in the precursor solution is 0.02-0.04M.
4. 4. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 1, the volume of the mixture of DMF and deionized water is 60-80ml, and the volume ratio of DMF to deionized water is 7:3-9:1.
5. 5. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in the step 1, the stirring time is 20-40min, and the stirring rate is 100-300 r.min -1 .
6. 6. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 3, the ambient temperature of the standing reaction is 20-30 ℃, and the nickel foam is completely immersed in the precursor solution.
7. 7. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 4, the washing is performed by alternately washing with deionized water and ethanol for 3-5 times, the drying is vacuum drying, the drying temperature is 40-50 ℃, and the drying time is 6-10 hours.
8. 8. The method for preparing NiFeCe-DHDBC MOF composite catalyst according to claim 1, wherein in step 2, the size of the nickel foam is 2-4cm x 2-4cm.
9. 9. Use of a foamed nickel composite catalyst obtained by the preparation method according to any one of claims 1-8 in electrolytic water oxygen evolution reaction OER.

Description

Preparation method of NiFeCe-DHDBC MOF composite catalyst and application of NiFeCe-DHDBC MOF composite catalyst in water electrolysis Technical Field The invention relates to the technical field of catalysts, in particular to a preparation method of NiFeCe-DHDBC MOF composite catalyst and application thereof in water electrolysis. Background The hydrogen energy is an important strategic direction for coping with energy crisis and environmental problems as clean, efficient and sustainable secondary energy, and has an irreplaceable position in energy transformation. The electrolytic water hydrogen production becomes the hydrogen energy preparation technology with the highest potential at present due to the advantages of wide raw material sources, high product purity, zero carbon emission and the like, but in the electrolytic water process, the Oxygen Evolution Reaction (OER) is used as a half reaction with slow dynamics, the problems of high overpotential and high energy consumption exist, the integral efficiency and the industrialized promotion of the electrolytic water hydrogen production are seriously restricted, and therefore, the development of an OER catalyst with high efficiency, stability and low cost is the core for breaking through the technical bottleneck. OER catalysts are currently largely classified into noble metal based catalysts (e.g., irO 2、RuO2) and non-noble metal based catalysts. The noble metal-based catalyst has excellent catalytic activity, but has rare reserves and high price, and can not meet the requirements of large-scale industrial production, and the transition metal-based catalyst (such as nickel-based and iron-based compounds) has abundant resources, low cost and adjustable electronic structure, thereby becoming the main stream direction for replacing the noble metal catalyst, wherein the nickel-iron-based catalyst shows better OER activity in alkaline electrolyte by virtue of the synergistic effect of binary metal, but the existing binary transition metal-based catalyst still has a short plate, namely the active attenuation is obvious under the working condition of high current density, the active site is easy to cover, the electronic structure regulation space is limited, and the catalytic performance is difficult to further optimize. MOF (metal organic framework) materials have the unique advantages of high specific surface area, rich active sites, adjustable structure and the like, and provide a new structural support for improving the performance of the catalyst. The rare earth element cerium (Ce) is introduced into a nickel-iron-based system to form a Ni, fe and Ce ternary metal synergistic system, the electron distribution can be circularly regulated by means of Ce 3+/Ce4+ valence state, the oxidation-reduction capacity and the structural stability of an active site are enhanced, and meanwhile, the structural advantages and the in-situ loading strategy of the MOF material are combined, so that the defect of the traditional transition metal-based catalyst is hopeful to be overcome. However, the research of combining the ternary metal and the MOF material for high-current density OER catalysis is still deficient, and the related catalyst has a large improvement space in stability and industrialization suitability, so that the non-noble metal OER catalyst with the synergistic effect of the ternary metal and the structural advantage of the MOF is developed, and the non-noble metal OER catalyst has important technical value and application prospect. In order to solve the problems, the application needs to provide a preparation method of NiFeCe-DHDBC MOF composite catalyst and application thereof in water electrolysis. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a preparation method of NiFeCe-DHDBC MOF composite catalyst and application thereof in electrolyzed water, wherein an MOF structure doped with ternary metals of Ni, fe and Ce is constructed, and an in-situ loading strategy is adopted to be combined with a foam nickel substrate, so that the structural advantages of the ternary metal synergistic effect and the MOF material are fully exerted, the OER catalytic activity, long-term stability and industrialization suitability of the catalyst are improved, the synthesis process is simplified, the raw material cost is controlled, and a high-efficiency non-noble metal catalytic solution is provided for the large-scale application of the electrolyzed water hydrogen production technology. In order to achieve the above purpose, the present invention adopts the following technical scheme: The preparation method of NiFeCe-DHDBC MOF composite catalyst, the NiFeCe-DHDBC MOF material is loaded on the surface of foam nickel in situ to form a composite catalytic system, the preparation method comprises the following steps: Step 1, preparing a precursor solution, namely sequentially adding a nickel salt, an iron salt and a cerium salt se