Atomically dispersed copper-nickel electrocatalyst for highly selective electroreduction of CO2 at a wide potential range

Designing and synthesising electrocatalysts with low overpotential, high activity, selectivity, and stability for the CO2 reduction reaction (CO2RR) is crucial for addressing environmental challenges and realising the artificial carbon cycle. In this study, we successfully synthesised a nitrogen-doped carbon-supported diatomic electrocatalyst comprising atomically dispersed CuN4 and NiN4 bimetallic centers. This was confirmed through extensive characterisation using high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy techniques. The as-synthesised CBN-CuNi electrocatalyst exhibited exceptional selectivity and stability in CO2RR. Over a wide potential range from − 0.60 to − 1.10 V vs RHE, CBN-CuNi maintained over 90% Faraday efficiency for CO (FECO) production. Notably, at − 0.9 V vs RHE, it achieved a remarkable selectivity with a maximum FECO of 97.9%, surpassing single metal catalysts, including CBN-Ni and CBN-Cu. Furthermore, CBN-CuNi demonstrated outstanding stability, sustaining over 90% FECO production for 40 h of continuous electrolysis, surpassing many existing electrocatalysts. These findings highlight the potential of the as-synthesised bimetallic electrocatalyst CBN-CuNi in the electrochemical reduction of CO2 to CO, contributing to advancing the artificial carbon cycle and addressing environmental concerns.