Nanowire arrays with abundant Cu–Ni interfaces for electroreduction of CO2 to ethylene

[Display omitted] •The nanoarray structure with abundant Cu–Ni interfaces is constructed in situ.•Nanoarray electrodes can facilitate rapid CO2 and charge transport.•The atomic interactions at the interface enhance the efficiency of C–C coupling.•The incorporation of Ni effectively enhances the CO2 activation process. Electrochemical reduction of CO2 to ethylene (C2H4), driven by renewable electricity, represents a strategy for sustainable development and carbon neutrality. However, continuous production of C2H4 at high efficiency and low cost remains a significant challenge. Herein, a synergistic approach using non-precious metals was employed, and in situ construction of a nanoarray structure with abundant Cu–Ni interfaces (Ni/Cu NWs) on a gas diffusion layer (GDL) was performed. The atomic interactions at the interface significantly enhanced the efficiency of C–C coupling. The Faraday efficiency (FE) for C2H4 production reached 58.65 %, and the current density of 253.42 mA cm−2 at −1.1 V, markedly surpassing that of bare Cu nanowire (Cu NWs, 25.33 %). By virtue of the in-situ construction on the GDL, the Cu–Ni interface catalyst demonstrated excellent stability, operating under high current for more than 72 h. In situ infrared characterization and theoretical calculations demonstrate that the incorporation of Ni effectively enhanced the CO2 activation process, which is beneficial for the accumulation of key intermediate of C–C coupling. At the Cu–Ni interface, the energy barrier for C–C coupling was reduced, thereby effectively promoting the conversion of C2H4. This work presents a solution strategy for the interfacial engineering of non-precious metal catalysts.