Nanocavity enriched CuPd alloy with high selectivity for CO2 electroreduction toward C2H4

Electrocatalysis of CO 2 reduction reaction is an effective way to convert CO 2 into high value-added products, but the selectivity of Cu-based catalysts for C 2+ products needs to be improved due to the high energy barrier of C–C coupling. Therefore, a viable catalyst design strategy to decrease energy barrier of C–C coupling should be put forward. Here, a nanocavity-enriched CuPd single atom alloy (CuPd SAA) catalyst is designed to promote C–C coupling process. The faradaic efficiency of CuPd SAA for ethylene and C 2+ reaches 75.6% and 85.7% at − 0.7 V versus reversible hydrogen electrode (RHE), respectively. Based on the results given by in situ characterization, the porous hollow structure dramatically increases the ratio of the linear-bond *CO, thus enhancing the faradaic efficiency for ethylene. Density functional theory (DFT) calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C–C coupling, further improving the faradaic efficiency. This work provides a new idea for designing catalyst with high selectivity for ethylene. Graphical abstract