Tunable Oxygen Vacancy Clusters Enhanced Catalytic Activity of CeO₂ Nanorods on CO₂ Cycloaddition

Abstract Constructing heterogeneous halogen‐free catalysts featuring efficiently activated CO 2 and epoxides for the synthesis of cyclic carbonates via an atom‐economical route is significant but remains a big challenge. In this work, we develop an atmosphere‐assisted strategy for preparing mesoporous CeO 2 nanorods with tunable oxygen vacancy cluster concentrations, which boosts the performance of CO 2 cycloaddition. Pair distribution function (PDF) analysis elucidates that oxygen vacancy clusters regulate the dynamic equilibrium of the multiscale structure of CeO 2 via a synergistic “compression‐expansion” mechanism. Furthermore, the high concentrations of oxygen vacancy clusters form abundant frustrated Lewis pairs (FLP) sites, which remarkably promote the adsorption and activation of CO 2 with epoxides. Thus, the performance of CO 2 cycloaddition was substantially intensified. A 95% yield of cyclic carbonate was obtained when the reaction was conducted with RNR‐CeO 2 ‐H 2 at 110 °C. Moreover, the kinetic properties and the catalytic mechanism of CO 2 cycloaddition on FLP sites in RNR‐CeO 2 ‐H 2 were investigated based on the in situ DRIFTS and DFT calculations. Thus, this work provides new insights into the design of high‐performance catalysts with tunable FLP sites for the efficient activation and conversion of CO 2 into value‐added chemicals by modulating oxygen vacancy cluster concentrations.