Metal oxides for the electrocatalytic reduction of carbon dioxide: Mechanism of active sites, composites, interface and defect engineering strategies.

[Display omitted] • CO 2 reduction reaction (CO 2 RR) into fine-chemicals is the most instant approach for balancing the atmospheric CO 2 level. • Herein, the recent advances in the product efficiency of CO 2 RR for metal oxide electrocatalysts are summarized. • The interface and vacancy defect engineering strategies, used to improve CO 2 RR performance are overviewed. • Overlooking the metal sites of metal oxide-based catalysts, M−O (metal–oxygen bond) active sites are discussed. The electrochemical reduction of CO 2 into fine chemicals, assisted with renewable energy, is the most instant approach for balancing the atmospheric CO 2 level, as well as for storing solar energy as chemical energy. Due to their easy synthesis and good performance, metal oxides are attractive as electrocatalysts for the CO 2 reduction reaction (CO 2 RR). In this review article, we concise the recent advances in the product efficiency of CO 2 RR for metal oxide electrocatalysts. It is here worth noticing that, overlooking the metal sites of metal oxide-based catalysts, we only considered the M−O (metal–oxygen bond) active sites for discussion. Further, recent strategies, such as advanced morphologies development and interface and vacancy defect engineering, used to improve the CO 2 RR performance, are also overviewed. By covering the critical role of catalysts (M−O) structure in efficiency and stability, this review also provides some future aspects for the design and development of efficient metal oxide-based electrocatalysts for CO 2 RR. [ABSTRACT FROM AUTHOR]