Highly Selective Carbon Dioxide Electroreduction on Structure-Evolved Copper Perovskite Oxide toward Methane Production

Electrochemical carbon dioxide (CO2) conversion is promising to balance the carbon cycle for human society. However, an efficient electrocatalyst is the key to determine the selective conversion of CO2 toward valuable products. We report herein an efficient La2CuO4 perovskite catalyst for electrochemical CO2 reduction. A high Faradaic efficiency of 56.3% with a partial current density of 117 mA cm–2 is achieved for methane production over this perovskite catalyst at −1.4 V (vs RHE). The results demonstrate that the structural evolution of La2CuO4 perovskite takes place simultaneously during the cathodic CO2 reduction process. Theoretical investigations further unravel that the emerging Cu/La2CuO4 interface accounts for the CO2 methanation behaviors. This work provides an effective perovskite electrocatalyst for ambient CO2 methanation and offers a valuable understanding of the structure evolution and surface reconstruction of precatalysts in catalytic reactions for energy-relevant technologies.