Single atom copper anchored N-doped graphene-like carbon for CO2 electroreduction

Abstract

Carbon-based materials are widely used as electrocatalysts for the CO₂ reduction reaction (CO₂RR) due to their high conductivity and large surface area. Recent studies highlighted that the presence of Cu in trace amounts over the graphene-based electrocatalyst significantly affects their electrochemical properties. Cu is particularly selective for forming hydrocarbons, and multi-carbon oxygenates at high efficiencies, unlike most electrocatalysts, primarily producing C1 products. Despite this, current electrocatalysts exhibit limited selectivity toward C2 products. In this study, the nitrogen-doped graphene-like framework was synthesised, and the effect of introducing trace levels of single-atom Cu (Cu@NG) on CO2RR was studied. DFT analysis was further performed to understand the mechanism involved during electrocatalysis, and the results were well aligned with the experimental data. The results confirm that the co-presence of graphitic-N and Cu single atoms in Cu@NG serves as the primary active species for CO₂RR. The electrocatalyst demonstrated excellent performance, achieving a faradaic efficiency (FE) of 91.0% at -0.8 V versus RHE, with a 59% FE specifically for C₂H₄ production. This highlights the potential of Cu@NG for selective CO₂RR toward multi-carbon products.