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 (Vo) 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 Vo defect engineering methods, and then, the catalytic mechanism and role of Vo for CO2RR to CO will illustrate how Vo promotes CO2 adsorption and activation and enhances the yield and selectivity of CO. Specifically, nanostructured perovskites with Vo for CO2RR into CO are briefly illustrated, and the approaches for Vo regeneration in the catalysts are mentioned. The challenges of the practical application of Vo-engineered catalysts are also discussed, and prospects for effective CO2RR into CO based on Vo defect engineering are proposed.