Application Of In-based Materials In Electrocatalytic Reduction Of Carbon Dioxide

Since the industrial revolution,the world industrialization process has made great strides,and the shortage of energy and environmental pollution have become major problems to be solved urgently all over the world.In recent years,the concentration of CO₂in the environment has been rising,and the greenhouse effect caused by it is more and more harmful to the ecological environment.Therefore,it is of epoch-making significance to study carbon dioxide pollution control technology.Electrochemical reduction of carbon dioxide（ECR）has many advantages,such as mild reaction conditions,simple operation,little pollution and the ability to produce chemical products with high added value.Therefore,it has attracted much attention from experts and scholars.Because of cheap,easy to obtain,less toxic and highly selective to formic acid,In-based catalysts have made great progress in ECR to carbon energy.However,the low current density and poor stability of In-based catalysts greatly limit the further practical application of indium-based catalysts.In view of the low current density and stability of In-based materials,indium catalyst with high current density was prepared by ZIF derivation method and calcination technology assisted by sodium chloride template.The main research contents are as follows:（1）Firstly,indium single atomic catalyst with plane-like structure was synthesized by the method of ZIF-8 derivatization,and indium single atomic catalyst could be anchored on N-doped carbon substrate to improve the stability of indium catalyst.The performance of the catalyst was studied by electrochemical experiments.According to the analysis of experimental results,compared with the traditional In-based catalyst,In-SACs has higher specific surface area and active sites because of its atomic dispersion structure,which makes In-SACs have better electrocatalytic activity and selectivity to formate.In the ECR process,indium atoms disperse and interact strongly with the electrons of the adjacent N atoms on the carbon skeleton,so that CO₂can be effectively converted into formate and it has a high Faraday efficiency about 85.2%at-1.31 V vs.RHE and good stability（the catalytic performance is still not attenuated after continuous electrolysis for 12 h）.（2）Secondly,the indium material was synthesized by calcination treatment assisted by sodium chloride template to improve the current density in the ECR.A series of 3D In SA_xcatalysts were synthesized by changing the initial addition amount of indium,and electrochemical experiments were carried out at room temperature.The experimental results show that 3D In SA₁₆₀material has the best properties.In the ECR,the catalyst has a high current density in a broad potential range,and the maximum current density can be up to-86 m A cm^-2.The results show that the catalyst has a three-dimensional lamellar structure with a specific surface area of 257.73 m²g^-1.The 3D structure of the sheet is beneficial to increase the exposure of catalytic reaction active sites,accelerate the diffusion rate of reactants on the catalyst surface and improve the activity of catalytic activator and the selectivity of formate.