Selective Photoconversion of CO2 to C2H4 on Asymmetrical CeO2―Cu2O Interfaces Driven by Oxygen Vacancies

Photocatalytic conversion of CO2 into valuable C2H4 is desirable for achieving a carbon-neutral future, yet faces sluggish kinetics of C & horbar;C dimerization and insufficient electron deliverability. Herein, an effective top-down etching route is presented to construct interfacial asymmetric oxygen vacancies (Ov) in CeO2 & horbar;Cu2O supported on the copper foam (CeO2 & horbar;Cu2O/CF). In situ characterizations and theoretical calculations demonstrate that the nanointerface-based CeO2 & horbar;Cu2O heterojunctions serve as rapid electron-transfer pathways, promoting efficiency without the need for sacrificial agents. Moreover, the asymmetric sites (Ce-Ov-Cu) with different charge distributions can effectuate C & horbar;C coupling reaction through the stabilization of the key *COCO intermediates, thus making CO2 reduction to C2H4 become a more favorable process. Accordingly, the optimized CeO2 & horbar;Cu2O/CF demonstrates remarkable performance with 93% electron selectivity toward C2H4 generation and an impressive production rate of 26.1 mu mol g(-1) h(-1). Such strongly coupled heterogeneous catalysts with finely tailored structure and interaction, containing asymmetric charge polarized metal sites at the interface, will provide some inspiration for constructing efficient photocatalysts to convert CO2 into high value-added multi-carbon products with solar energy.