Promoting electrochemical reduction of CO2 to ethanol by B/N-doped sp3/sp2 nanocarbon electrode

Electrochemical reduction of CO2 to value-added chemicals holds promise for carbon utilization and renewable electricity storage. However, selective CO2 reduction 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 CO2 to ethanol at relatively low overpotentials. CO2 reduction occurs with a Faradaic efficiency of 58.8%-69.1% for ethanol and acetate production at -0.5 similar to -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 sp(2) carbon reducing the overpotential for CO2 reduction to ethanol. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.