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

Abstract

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.