Electrochemical CO2 reduction to ethylene by ultrathin CuO nanoplate arrays

Electrochemical reduction of CO2 to multi-carbon fuels and chemical feedstocks is an appealing approach to mitigate excessive CO2 emissions. However, the reported catalysts always show either a low Faradaic efficiency of the C2+ product or poor long-term stability. Herein, we report a facile and scalable anodic corrosion method to synthesize oxygen-rich ultrathin CuO nanoplate arrays, which form Cu/Cu2O heterogeneous interfaces through self-evolution during electrocatalysis. The catalyst exhibits a high C2H4 Faradaic efficiency of 84.5%, stable electrolysis for similar to 55 h in a flow cell using a neutral KCI electrolyte, and a full-cell ethylene energy efficiency of 27.6% at 200 mA cm(-2) in a membrane electrode assembly electrolyzer. Mechanism analyses reveal that the stable nanostructures, stable Cu/Cu2O interfaces, and enhanced adsorption of the *OCCOH intermediate preserve selective and prolonged C2H4 production. The robust and scalable produced catalyst coupled with mild electrolytic conditions facilitates the practical application of electrochemical CO2 reduction.

Automated summary

In this study, a facile and scalable anodic corrosion method was used to synthesize oxygen-rich CuO nanoplate arrays. The self-evolution process led to the formation of stable Cu/Cu2O heterogeneous interfaces, which significantly improved the C2H4 production and stability in CO2 electroreduction.