Interfacial Synergy between the Cu Atomic Layer and CeO₂ Promotes CO Electrocoupling to Acetate

Cu is considered to be an effective electrocatalyst in CO/CO₂ reduction reactions (CORR/CO₂RR) because of its C-C coupling into C₂₊ products, but it still remains a formidable challenge to rationally design Cu-based catalysts for highly selective CO/CO₂ reduction to C₂₊ liquid products such as acetate. We here demonstrate that spraying atomically layered Cu atoms onto CeO₂ nanorods (Cu-CeO₂) can lead to a catalyst with an enhanced acetate selectivity in CORR. Owing to the existence of oxygen vacancies (O_v) in CeO₂, the layer of Cu atoms at interface coordinates with Ce atoms in the form of Cu-Ce (O_v), as a result of strong interfacial synergy. The Cu-Ce (O_v) significantly promotes the adsorption and dissociation of H₂O, which further couples with CO to selectively produce acetate as the dominant liquid product. In the current density range of 50-150 mA cm^-2, the Faradaic efficiencies (FEs) of acetate are over 50% with a maximum value of 62.4%. In particular, the turnover frequency of Cu-CeO₂ reaches 1477 h^-1, surpassing that of Cu nanoparticle-decorated CeO₂ nanorods, bare CeO₂ nanorods, as well as other existing Cu-based catalysts. This work advances the rational design of high-performance catalysts for CORR to highly value-added products, which may attract great interests in diverse fields including materials science, chemistry, and catalysis.