CO₂-assisted formation of grain boundaries for efficient CO–CO coupling on a derived Cu catalyst

Abstract

The electrochemical CO2 reduction reaction (CO2RR) on Cu catalyst holds great promise for converting CO2 into valuable multicarbon (C2+) compounds, but still suffers poor selectivity due to the sluggish kinetics of forming carbon–carbon (C–C) bonds. Here we reported a perovskite oxide-derived Cu catalyst with abundant grain boundaries for efficient C–C coupling. These grain boundaries are readily created from the structural reconstruction induced by CO2-assisted La leaching. Using this defective catalyst, we achieved a maximum C2+ Faradaic efficiency of 80.3% with partial current density over 400 mA cm−2 in neutral electrolyte in a flow-cell electrolyzer. By combining the structural and spectroscopic investigations, we uncovered that the in-situ generated defective sites trapped by grain boundaries enable favorable CO adsorption and thus promote C–C coupling kinetics for C2+ products formation. This work showcases the great potential of perovskite materials for efficient production of valuable multicarbon compounds via CO2RR electrochemistry.

Keywords

• electrochemical CO₂ reduction
• multicarbon products
• perovskite oxide
• structural evolution
• defective sites