Efficient Electrocatalytic CO2 Reduction to C2+ Alcohols at Defect-Site-Rich Cu Surface

Summary

Electrochemical CO₂ reduction is a promising approach for upgrading excessive CO₂ into value-added chemicals, while the exquisite control of the catalyst atomic structures to obtain high C₂₊ alcohol selectivity has remained challenging due to the intrinsically favored ethylene pathways at Cu surface. Herein, we demonstrate a rational strategy to achieve ∼70% faradaic efficiency toward C₂₊ alcohols. We utilized a CO-rich environment to construct Cu catalysts with stepped sites that enabled high surface coverages of ∗CO intermediates and the bridge-bound ∗CO adsorption, which allowed to trigger CO₂ reduction pathways toward the formation alcohols. Using this defect-site-rich Cu catalyst, we achieved C₂₊ alcohols with partial current densities of > 100 mA·cm⁻² in both a flow-cell electrolyzer and a membrane electrode assembly (MEA) electrolyzer. A stable alcohol faradaic efficiency of ∼60% was also obtained, with ∼500 mg C₂₊ alcohol production per cm² catalyst during a continuous 30-h operation.