Liquid-Liquid Interface -Driven Reconstruction of CuAg Nanocomposites for Selective CO2 to C2H4 Electroreduction.

The electrochemical CO2 reduction reaction (CO2RR) to multicarbon products such as C2H4 is critical for sustainable energy conversion but remains a significant challenge. Cu-based nanocatalysts can facilitate C─C coupling for C2+ product generation, yet their catalytic efficiency and selectivity require further improvement. In this study, a liquid-liquid interface etching strategy is employed, using Cu nanocubes as templates and aqueous AgNO3 as the etchant to synthesize well-defined CuAg nanocomposites. Among these, the optimized Cu67Ag33 composite nanocubes achieved a ethylene (C2H4) Faraday efficiency (FE) of 43.90% and a partial current density of 21.50 mA cm-2at -1.50 VRHE. This work demonstrates a versatile approach to integrate secondary metal active sites via directional confined etching, while reconstructing catalytic interfaces to enhance C─C coupling and C2H4 selectivity. These findings provide a strategic framework for the rational design of efficient CO2RR catalysts, advancing the development of sustainable carbon conversion technologies.