Design Of Fe-based Bimetallic Catalysts And Study On The Peformance Of Electrocatalytic CO₂ Reduction/O₂ Evolution

With the growing energy crisis and environmental pollution,there is an urgent need to explore alternative energy conversion and storage devices.The electrochemical conversion of CO₂ into value-added chemicals and fuels using renewable energy sources is a very effective approach to improving energy efficiency and protecting the environment.Diatomic catalysts（DACs）,as an emerging research direction,provide more flexible active sites for electrocatalytic reactions with multiple electron/proton transfer such as carbon dioxide reduction reactions（CO₂RR）.Herein,electrochemical CO₂RR catalysts with Cu and Fe highly dispersed on three-dimensional carbon and nitrogen substrates（Cu-Fe/N-C）were designed and prepared in this work.Such a catalyst not only surmounts the disadvantage of single Cu or Fe electrode,but also exhibits high selectivity for CO production.Faraday efficiencies over 90%for CO were achieved over a wide potential range of-0.7 V～-0.9 V（V vs.RHE）,and 99.8%for CO at-0.8 V（V vs.RHE）,which is 1.70 and 1.37 times higher than the Faraday efficiencies of Cu/N-C and Fe/N-C.Cu-Fe/N-C also exhibits robust stability during electrolysis,with about 98%CO selectivity retained after 14 h of electrolysis.Oxygen evolution reaction（OER）is an important anode reaction in energy conversion and storage,so it is important to develop efficient OER electrocatalysts.In general,the catalytic active center plays a direct role in the performance of OER.In this work,halogen（F,Cl,Br）-doped FeNi bimetallic catalysts were designed and synthesized to investigate the effect of halogen doping on the performance of OER.It was found that the OER Activity of FeNi-Cl/NC was much better than that of FeNi-F/NC and FeNi-Br/NC,indicating that the introduction of halogens may modulate the OER performance of FeNi bimetallic.