Engineering Atom‐Scale Cascade Catalysis via Multi‐Active Site Collaboration for Ampere‐Level CO2 Electroreduction to C2+ Products

Abstract Electrochemical reduction of CO2 to value‐added multicarbon (C2+) productions offers an attractive route for renewable energy storage and CO2 utilization, but it remains challenging to achieve high C2+ selectivity at industrial‐level current density. Herein, a Mo1Cu single‐atom alloy (SAA) catalyst is reported that displays a remarkable C2+ Faradaic efficiency of 86.4% under 0.80 A cm−2. Furthermore, the C2+ partial current density over Mo1Cu reaches 1.33 A cm−2 with a Faradaic efficiency surpasses 74.3%. The combination of operando spectroscopy and density functional theory (DFT) indicates the as‐prepared Mo1Cu SAA catalyst enables atom‐scale cascade catalysis via multi‐active site collaboration. The introduced Mo sites promote the H2O dissociation to fabricate active *H, meanwhile, the Cu sites (Cu0) far from Mo atom are active sites for the CO2 activation toward CO. Further, CO and *H are captured by the adjacent Cu sites (Cu&+) near Mo atom, accelerating CO conversion and C─C coupling process. Our findings benefit the design of tandem electrocatalysts at atomic scale for transforming CO2 to multicarbon products under a high conversion rate.