Selective CO2 Electroreduction to Ethanol over a Carbon-Coated CuO_x Catalyst

摘要

The design of efficient copper(Cu)-based catalysts is critical for CO2 electroreduction into multiple carbon products. However, most Cu-based catalysts are favorable for ethylene production while selective production of ethanol with high Faradaic efficiency and current density still remains a great challenge. Herein, we design a carbon-coated CuO_x (CuO_x@C) catalyst through one-pot pyrolysis of Cu-based metal-organic framework (MOF), which exhibits high selectivity for CO2 electroreduction to ethanol with Faradaic efficiency of 46%. Impressively, the partial current density of ethanol reaches 166 mA cm~(-2), which is higher than that of most reported catalysts. Operando Raman spectra indicate that the carbon coating can efficiently stabilize Cu~+ species under CO2 electroreduction conditions, which promotes the C-C coupling step. Density functional theory (DFT) calculations reveal that the carbon layer can tune the key intermediate ~*HOCCH goes the hydrogenation pathway toward ethanol production.