Construction of stable Cu+/Cu0 interfaces via in situ cyclic voltammetry for CO2 electrochemical reduction to ethylene under high current density

Electrochemical CO 2 reduction reaction (CO 2 RR) coupled with renewable electricity offers a promising strategy to convert CO 2 into value-added chemicals while addressing the challenges of carbon emissions. Although copper-based catalysts have demonstrated promising capability in CO 2 -to-hydrocarbon conversion, achieving highly selective and energy-efficient production of C 2+ products, particularly ethylene (C 2 H 4 ), remains a significant challenge. Herein, we report a novel strategy to construct oxidation-derived copper (ODCu) nanowire catalysts through a combination of electrodeposition, wet-chemical synthesis, and cyclic voltammetry (CV) redox process. During the CV treatment, the catalyst undergoes in situ surface reconstruction, resulting in the formation of abundant Cu + /Cu 0 interfaces. The optimized ODCu nanowire catalyst exhibits remarkable C 2 H 4 selectivity with a faradaic efficiency (FE) of 54 % ± 4 % and a partial current density of 154 ± 12 mA·cm −2 at −1.0 V (vs reversible hydrogen electrode, RHE), demonstrating stable performance for 12 h. Through in situ infrared spectroscopy (FTIR) analysis and density functional theory (DFT) calculations, we reveal that the engineered Cu + /Cu 0 interfaces significantly lower the activation energy barrier for C C coupling, thereby promoting the selective formation of C 2 H 4 . This work provides new insights into interface engineering for enhanced CO 2 RR performance and offers an effective strategy for developing high-performance copper-based electrocatalysts.