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.