Engineering Atom-scale Cascade Catalysis via Multi-active Site Collaboration for Ampere-level CO 2 Electroreduction to C 2+ Products

Electrochemical reduction of CO 2 to value-added multicarbon (C 2+ ) productions offers an attractive route for renewable energy storage and CO 2 utilization, but it remains challenging to achieve high C 2+ selectivity at industrial-level current density. Herein, we report a Mo 1 Cu single-atom alloy (SAA) catalyst that displays a remarkable C 2+ Faradaic efficiency of 86.4% under 0.80 A cm -2 . Furthermore, the C 2+ partial current density over Mo 1 Cu 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 Mo 1 Cu SAA catalyst enables atom-scale cascade catalysis via multi-active site collaboration. The introduced Mo sites promote the H 2 O dissociation to fabricate active *H, meanwhile, the Cu sites (Cu 0 ) far from Mo atom are active sites for the CO 2 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 CO 2 to multicarbon products under high conversion rate.