Correlating the valence state of a Cu-based electrocatalyst for CO2 reduction to C2+

In this study, a facile ligand-protected strategy for preparing Cu@Cu2O and CuO nanoparticles is presented. The electrocatalyst efficacy of the CuO variant, particularly for CO2 reduction to multi-carbon products (C2+), is significant, boasting faradaic efficiencies (FEs) surpassing 85% and a current density peak at 340 mA cm-2. This exceptional performance markedly exceeds that of the Cu@Cu2O electrocatalyst. This observed enhancement in the electrosynthesis efficiency of C2+ is attributed to the abundant Cu0 active sites, which originate from the in situ electroreduction of CuO.