Preparation Of Self-Supporting Bimetal （Nitride） Material And The Performance Of 5-Hydroxymethyl Furfural Electrooxidation And Carbon Dioxide Electroreduction

Due to the excessive consumption of fossil fuels,energy shortage and environmental pollution have become increasingly serious problems.The conversion of renewable feedstocks on the earth to different types of commodity chemicals driven by renewable electricity is considered as a green and sustainable chemistry process to reduce the dependence on fossil fuels.The electrocatalytic oxidation of5-hydroxymethylfurfural（5-hydroxymethylfurfural oxidation reaction,HMFOR）and electrochemical reduction of carbon dioxide（Carbon dioxide reduction reaction,CO₂RR）can produce high value-added chemicals under mild conditions,thus promoting low-carbon and green development.However,due to the presence of multiple reaction intermediates,HMFOR and CO₂RR typically result in poor selectivity and low efficiency.Therefore,the design of low-cost and efficient catalysts for HMFOR and CO₂RR is of great significance for alleviating the energy crisis and promoting the utilization of renewable energy.In this dissertation,taking self-supported bimetallic-based electrode materials as the research object,nickel-cobalt bimetallic nitride catalysts and copper-based bimetallic catalysts were designed and synthesized,for the applications in HMFOR and CO₂RR reactions.The main research contents are as follows:（1）A nickel-cobalt bimetallic nitride catalyst（Ni₈Co₂-N）growing on nickel foam was prepared by a liquid phase growth-etching-calcination route,and excellent HMFOR performance was obtained.When the current density was 50 m A cm^-2,the Ni₈Co₂-N required potential of merely 1.37 V versus reversible hydrogen electrode（RHE）,the Faradaic efficiency of 2,5-furandicarboxylic acid（FDCA）reached 94.4%,and the FDCA yield rate was 166.8μmol cm^-2 h^-1,which overperform most other reported Ni/Co-based catalysts.The catalyst still retained its structural integrity after six cycles.The excellent catalytic selectivity and stability are attributed to the synergistic effect between Ni₃N and Co₃N in Ni₈Co₂-N.The coupling of Ni⁺and Co⁺promotes the formation of Ni²⁺and Co²⁺,which is considered the catalytic active sites for HMFOR.Furthermore,assembling HMFOR and hydrogen evolution reaction by using the Ni₈Co₂-N as a bifunctional catalyst effectively maximized the energy utilization efficiency（2）A copper-based bimetallic catalyst（Cu_xO-Au）loading on the copper foam was prepared via a liquid phase growth-calcination-etching route.Cu_xO-Au tandem catalysts with different amounts of Au loadings were synthesized by controlling the concentration of HAu Cl₄ to improve the selectivity and efficiency of CO₂RR to C2products.Based on the determination of CO₂RR products on the copper substrate and Cu_xO reference,the influence of the substrate on CO₂RR performance was excluded and the tandem catalysis of Cu_xO-Au was preliminarily confirmed.The experiment results indicate that the Cu_xO-Au-0.25 catalyst with an Au loading of 20%weight percent holds the optimized synergistic effect between Cu_xO and Au,thus exhibiting higher current density,and higher Faradaic efficiency of C2 product over other compared samples.This work could inspire the design and synthesis of tandem catalysts for CO₂RR.Overall,this dissertation designs highly efficient catalysts for HMFOR and CO₂RR,and discusses the catalytic reaction mechanism,which may inspire the designing of low-cost and highly efficient catalysts.