Recent advances in inorganic catalysts for CO₂ cycloaddition reactions: catalysts, engineering strategies and mechanism

The catalytic cycloaddition of CO₂ to epoxides for the synthesis of cyclic carbonates represents a cornerstone of CO₂ utilization within the green chemistry paradigm. This review comprehensively summarizes recent advances in the application of inorganic catalysts, including metal oxides, boron-based materials, and graphitic carbon nitride, with elaborated mechanistic insights into their unique activation pathways. Key material engineering strategies such as heteroatom doping, defect engineering, and crystal facet tuning are highlighted for their role in enhancing catalytic performance. Despite progress, significant challenges remain, particularly in developing co-catalyst-free systems that operate under mild conditions. This review critically discusses these challenges and outlines future research directions, emphasizing the rational design of intrinsic bifunctional catalysts, the adoption of greener reaction media, and the development of scalable synthesis methods to bridge the gap between laboratory innovation and industrial application.