Direct electrochemical nitrate reduction to ammonia(NRA)synthesis is an efficient and environmentally friendly production technology.However,the development of highly selective electrocatalysts is still a challenge du...Direct electrochemical nitrate reduction to ammonia(NRA)synthesis is an efficient and environmentally friendly production technology.However,the development of highly selective electrocatalysts is still a challenge due to the nine-proton and eight-electron reduction reaction.High-entropy alloys(HEAs)contain a wide range of elements and have adjustable properties,giving them excellent application potential in multi-step reactions.In this work,we skillfully use the local high temperature and excellent thermal conductivity generated at the reduced graphene oxide(rGO)defect in a microwave process to achieve a rapid quenching process in 10 seconds.This approach overcomes element immiscibility and results in a self-supported,single-phase,non-precious metal and uniform FeCoNiCuSn alloy electrode.The HEAs reach a remarkable NH3 yield of 883.7±11.2μg h^(-1) cm^(-2),maximum faradaic efficiency(FE)of 94.5±1.4%,and highest NH3 selectivity of 90.4±2.7%.Experimental and theoretical calculations reveal that the presence of multiple adjacent elements in HEAs triggers a synergistic catalytic effect,while the excellent mass and charge transfer properties of rGO jointly encourage the performance of the electrochemical NRA.In particular,NO3-favors vertical adsorption at Fe-Fe sites,and the desorption of NH3 is identified as the rate-determining step(RDS)with an extremely smallΔG value of 0.7 eV.展开更多
基金supported by the National Natural Science Foundation of China(No.21872034)the Project of the Natural Science Foundation of Fujian Province(No.2019J01746)+1 种基金the Open Fund of Fujian Key Laboratory of Electrochemical Energy Storage Materials,Fuzhou University(No.2021CN01)the Natural Science Foundation of Zhangzhou City(No.ZZ2024J16).
文摘Direct electrochemical nitrate reduction to ammonia(NRA)synthesis is an efficient and environmentally friendly production technology.However,the development of highly selective electrocatalysts is still a challenge due to the nine-proton and eight-electron reduction reaction.High-entropy alloys(HEAs)contain a wide range of elements and have adjustable properties,giving them excellent application potential in multi-step reactions.In this work,we skillfully use the local high temperature and excellent thermal conductivity generated at the reduced graphene oxide(rGO)defect in a microwave process to achieve a rapid quenching process in 10 seconds.This approach overcomes element immiscibility and results in a self-supported,single-phase,non-precious metal and uniform FeCoNiCuSn alloy electrode.The HEAs reach a remarkable NH3 yield of 883.7±11.2μg h^(-1) cm^(-2),maximum faradaic efficiency(FE)of 94.5±1.4%,and highest NH3 selectivity of 90.4±2.7%.Experimental and theoretical calculations reveal that the presence of multiple adjacent elements in HEAs triggers a synergistic catalytic effect,while the excellent mass and charge transfer properties of rGO jointly encourage the performance of the electrochemical NRA.In particular,NO3-favors vertical adsorption at Fe-Fe sites,and the desorption of NH3 is identified as the rate-determining step(RDS)with an extremely smallΔG value of 0.7 eV.
