CO2 Electroreduction at Low Overpotential on Oxide-Derived Cu/Carbons Fabricated from Metal Organic Framework

Electrochemical reduction of CO2 to chemical feedstocks is an attractive solution that prevents CO2 accumulation in the atmosphere, but it remains a great challenge to develop the cost-effective catalysts. Herein, we synthesized oxide-derived Cu/carbon (OD Cu/C) catalysts by a facile carbonization of Cu-based MOF (HKUST-1). The resulting materials exhibited highly selective CO2 reduction to alcohol compounds with total faradic efficiencies of 45.2-71.2% at -0.1 to -0.7 V versus reversible hydrogen electrode (RHE). High-yield methanol and ethanol has been achieved on OD Cu/C-1000 with the production rates of 5.1-12.4 and 3.7-13.4 mg L-1 h-1, respectively. Notably, the onset potential for C2H5OH formation is near -0.1 V (versus RHE), corresponding to ∼190 mV of overpotential, which is among the lowest overpotentials reported to date for the reduction of CO2 to C2H5OH. The improvements in activity and selectivity of the oxide-derived Cu/carbon might be attributed to the synergistic effect between the highly dispersed copper and the matrix of porous carbon. These findings provide a new insight into design of practical catalysts for decreasing atmospheric CO2 levels and synthesizing liquid fuels.