Low‐Crystalline AuCuIn Catalyst for Gaseous CO₂ Electrolyzer

Abstract Despite its importance for the establishment of a carbon‐neutral society, the electrochemical reduction of CO₂ to value‐added products has not been commercialized yet because of its sluggish kinetics and low selectivity. The present work reports the fabrication of a low‐crystalline trimetallic (AuCuIn) CO₂ electroreduction catalyst and demonstrates its high performance in a gaseous CO₂ electrolyzer. The high Faradaic efficiency (FE) of CO formation observed at a low overpotential in a half‐cell test is ascribed to the controlled crystallinity and composition of this catalyst as well as to its faster charge transfer, downshifted d‐band center, and low oxophilicity. The gaseous CO₂ electrolyzer with the optimal catalyst as the cathode exhibits superior cell performance with a high CO FE and production rate, outperforming state‐of‐the‐art analogs. Thus, the obtained results pave the way to the commercialization of CO₂ electrolyzers and promote the establishment of a greener society.