Dual-atomic Cu-Ag pairs boosting selective electroreduction of CO₂ to acetate

Single-atomic Cu catalysts show promise for the electrochemical CO₂ reduction (CO₂RR) to acetate, but their efficiency is limited by the difficulty in generating the CO intermediate needed for C-C coupling. While co-catalysts can enhance CO generation, weak interaction between co-catalytic and single-atom Cu sites hinders CO spillover, resulting in low acetate yield. Herein, we design atomic Cu-Ag pairs to enhance CO generation and facilitate CO spillover from Ag to Cu in the CO₂RR to enhance acetate production. The Cu-Ag/NC catalyst shows a high faradaic efficiency of 50% for acetate and 72% for C₂ products at -0.5 V versus a reversible hydrogen electrode, significantly outperforming single-atomic Cu catalysts. Theoretical calculations and in situ characterization demonstrate that the Cu-Ag bonding can facilitate the *CO spillover from Ag to Cu sites, while the electronic modification of Cu by Ag accelerates the subsequent formation of acetate on Cu sites.