Oxophilicity-Controlled CO₂ Electroreduction to C₂₊ Alcohols over Lewis Acid Metal-Doped Cu^δ+ Catalysts

Abstract

Cu-based electrocatalysts have great potential for facilitating CO 2 reduction to produce energy-intensive fuels and chemicals. However, it remains challenging to obtain high product selectivity due to the inevitable strong competition among various pathways. Here, we propose a strategy to regulate the adsorption of oxygen-associated active species on Cu by introducing an oxophilic metal, which can effectively improve the selectivity of C 2+ alcohols. Theoretical calculations manifested that doping of Lewis acid metal Al into Cu can affect the C–O bond and Cu–C bond breaking toward the selectively determining intermediate (shared by ethanol and ethylene), thus prioritizing the ethanol pathway. Experimentally, the Al-doped Cu catalyst exhibited an outstanding C 2+ Faradaic efficiency (FE) of 84.5% with remarkable stability. In particular, the C 2+ alcohol FE could reach 55.2% with a partial current density of 354.2 mA cm –2 and a formation rate of 1066.8 μmol cm –2 h –1 . A detailed experimental study revealed that Al doping improved the adsorption strength of active oxygen species on the Cu surface and stabilized the key intermediate *OC 2 H 5, leading to high selectivity toward ethanol. Further investigation showed that this strategy could also be extended to other Lewis acid metals.