Selective Electrochemical Reduction of Carbon Dioxide to Ethanol on a Boron- and Nitrogen-Co-doped Nanodiamond

Abstract

Electrochemical reduction of CO_2 to ethanol, a clean and renewable liquid fuel with high heating value, is an attractive strategy for global warming mitigation and resource utilization. However, converting CO_2 to ethanol remains great challenge due to the low activity, poor product selectivity and stability of electrocatalysts. Here, the B- and N-co-doped nanodiamond (BND) was reported as an efficient and stable electrode for selective reduction of CO_2 to ethanol. Good ethanol selectivity was achieved on the BND with high Faradaic efficiency of 93.2 % (−1.0 V vs. RHE), which overcame the limitation of low selectivity for multicarbon or high heating value fuels. Its superior performance was mainly originated from the synergistic effect of B and N co-doping, high N content and overpotential for hydrogen evolution. The possible pathway for CO_2 reduction revealed by DFT computation was CO_2→*COOH→*CO→*COCO→*COCH_2OH→*CH_2OCH_2OH→CH_3CH_2OH.