Dynamic Restructuring of Homogeneous Cu–Ag Nanoparticles Enriches Their Interfaces to Boost C2+ Production during CO Electroreduction

Abstract Gaining insight into the correlation between the structure and chemical state with the catalytic performance of Cu-based catalysts is quite essential for rational catalyst design during CO electroreduction (CORR) because of the structural sensitivity of Cu-based catalysts under electrocatalytic conditions. In this work, uniform Cu–Ag precursors with controlled stoichiometry were prepared. They evolved into Cu/Ag interfacial catalysts, delivering 95.2% C2+ Faradaic efficiency (FE) and >–250 mA cm–2 partial current density for Cu48Ag (atomic ratio of Cu to Ag is 48:1) in the CORR. In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and theoretical calculations reveal that abundant Cu–Ag interfaces effectively regulate *H and *CO coverage and stabilize the key intermediate *OCCOH, thereby leading to an enhanced activity and selectivity of C2+ products. Our findings provide a foundational paradigm for deciphering structure–function relationships in CORR electrocatalysis.