Promoting electrochemical reduction of CO2 to ethanol by B/N-doped sp~3/sp~2 nanocarbon electrode

Electrochemical reduction of CO2to value-added chemicals holds promise for carbon utilization and renewable electricity storage.However,selective CO2reduction to multi-carbon fuels remains a significant challenge.Here,we report that B/N-doped sp~3/sp~2 hybridized nanocarbon(BNHC),consisting of ultrasmall nanoparticles with a sp~3 carbon core covered by a sp~2 carbon shell,is an efficient electrocatalyst for electrochemical reduction of CO2to ethanol at relatively low overpotentials.CO2reduction occurs with a Faradaic efficiency of 58.8%-69.1 % for ethanol and acetate production at-0.5～-0.6 V(vs.RHE),among which 51.6%-56.0% is for ethanol.The high selectivity for ethanol is due to the integrated effect of sp~3/sp~2 carbon and B/N doping.Both sp~3 carbon and B/N doping contribute to enhanced ethanol production with sp2 carbon reducing the overpotential for CO2reduction to ethanol.