Grain boundary engineering of CeO2 induced electron redistribution for dimethyl carbonate synthesis from CO2

Direct synthesis of dimethyl carbonate (DMC) from CO 2 is critical for achieving carbon neutrality, yet the sluggish formation and conversion of the key *CH₃OCOO intermediate-due to the difficulty of C-O coupling-limit high DMC yields. Herein, we developed a boric acid-assisted recrystallization strategy to fabricate grain-boundary-rich CeO 2 hollow nanospheres, which serve as an efficient catalyst for CO 2 to DMC synthesis. The introduction of grain-boundary (GBs) induced the electron redistribution, which led a decrease in the electron density of bulk Ce ions and created a localized electron-rich region at homogeneous interface. This unique electronic landscape promoted reactive methoxy formation and stronger CO 2 adsorption, thereby enabling more efficient coupling of *CH 3 O and *CO 2 to form the *CH 3 OCOO. Concurrently, the enhanced CO 2 adsorption facilitated the dissociation of *CH 3 OCOO and subsequent DMC formation. As a result, the 4%BCeO 2 -GBs achieved an advantageous DMC yield of 19.8 mmol/g. In the assistance of dehydrating agent, the catalyst delivered a remarkable 264.2 mmol/g DMC yield and 7.12% methanol conversion, which was 32 times higher than commercial CeO 2 . This study elucidated the intrinsic mechanisms governing *CH 3 OCOO intermediate behavior and offers valuable guidance for CO 2 converting into high-value organic chemicals.