Oxygen vacancy regulation in CO2 methanation Catalysis: Mechanistic insights and research advances

CO₂ methanation represents a key technology for achieving carbon neutrality, which converts CO₂ into CH₄ to reduce greenhouse gas emissions and enable cyclic utilization of carbon resources. In thermocatalytic CO₂ methanation, the structural characteristics of O_Vs significantly affect the reaction pathway and catalyst performance. However, the structure-activity relationships of O_Vs in catalysts have not been systematically summarized, restricting the rational design of high-performance catalysts. This review focuses on O_Vs on the surface of CO₂ methanation catalysts, analyzes the mechanism by which O_Vs promote CO₂ adsorption, activation and intermediate transformation, summarizes the influence of O_V regulation strategies (including support type and morphology selection, promoters addition, and preparation method optimization, etc.) on catalytic performance, points out current research limitations, and prospects the potential breakthroughs of O_V regulation in the development of efficient catalysts, so as to provide theoretical guidance for the cyclic utilization of carbon resources.