A Review on Modulating Oxygen Vacancy Defect of Catalysts to Promote CO₂ Reduction Reaction to CO

Global warming and the energy crisis force the transformation of sustainable and environmentally friendly production and lead to the development of novel strategies and methodologies to contribute to enhancement of human well-being. Oxygen vacancy (V_o) defects engineering should be a cost-effective, green, and effective strategy for significantly promoting catalytic activity of CO₂RR to CO via optimizing the electronic structure, improving the photo adsorption, facilitating the electron-hole separation, promoting the reactive radical production, etc. This review discusses the V_o defect engineering methods, and then, the catalytic mechanism and role of V_o for CO₂RR to CO will illustrate how V_o promotes CO₂ adsorption and activation and enhances the yield and selectivity of CO. Specifically, nanostructured perovskites with V_o for CO₂RR into CO are briefly illustrated, and the approaches for V_o regeneration in the catalysts are mentioned. The challenges of the practical application of V_o-engineered catalysts are also discussed, and prospects for effective CO₂RR into CO based on V_o defect engineering are proposed.