Tuning the selectivity of CO2 electroreduction on Cu/In2O3 heterogeneous interface

The electrochemical reduction of CO2 is an effective approach to reduce and utilize CO2 for carbon neutral under mild conditions, meanwhile, the development of efficient and stable catalysts with large area and low cost is more conducive to the industrialization of CO2 electroreduction. The metal-oxide heterogeneous interface can promote the activation and conversion of CO2 due to the synergy effect between the metal and the oxide. Therefore, Cu/In2O3 electrodes are fabricated by magnetron sputtering in one step to achieve high selectivity of CO or CH3OH at different potentials. The highest Faradaic efficiency of CO is 78% at − 0.75 V, and unexpectedly, the Faradaic efficiency of CH3OH at − 0.55 V can reach 56%. The abundance of heterogeneous interfaces in Cu/In2O3 provides more active sites, reduces the work function and shifts the d‐band center upward. The catalytic performance was improved by electron transfer promotion and enhanced CO adsorption. Such advantages are responsible for the unique catalytic properties of the metal-oxide electrodes and provide a novel insight to develop large area metal-oxide electrodes for CH3OH preparation.