Highly dispersive trace silver decorated Cu/Cu2O composites boosting electrochemical CO2 reduction to ethanol

•Ag decorated Cu-based bimetallic structure featuring with highly dispersive trace Ag was designed.•Cu/Cu2O with merely 0.6 at.% silver decoration exhibits a significant enhancement in C2+ production.•The enhanced affinity with oxygen-adsorbed intermediates on Cu-Ag catalysts facilitates the selective formation of ethanol.