Boosting CO ₂ Fixation into Dimethyl Carbonate via Multiple Active Sites Constituted by V _O‐Ce‐O Vacancy Clusters on Single‐Unit‐Cell CeO ₂ Nano‐Sheets

Abstract The thermodynamic stability and intrinsic kinetic inertia of CO 2 present a critical challenge for its effective activation in the synthesis of high‐value dimethyl carbonate (DMC). In this work, we report the fabrication of novel O‐Ce‐O vacancy clusters (V O‐Ce‐O ) incorporated into CeO 2 nano‐sheets with a near single‐unit‐cell thickness to construct atomically adjacent multiple active sites on their surfaces. These active sites significantly enhance the activation of both CO 2 and CH 3 OH. Impressively, the as‐prepared CeO 2 with V O‐Ce‐O catalyst exhibits an excellent DMC yield of 31.2 mmol g −1 , surpassing previously reported Ce‐based catalysts under equivalent reaction conditions. Experimental results and theoretical calculations reveal that oxygen vacancy increases the reducibility of lattice oxygen, facilitating CO 2 activation, while cerium vacancies weaken the *CH 3 O adsorption, promoting the coupling reaction between *CH 3 O and *CO 2 to form the intermediate (*CH 3 OC(O) 2 ). Notably, the formation of vacancy clusters reduces the energy barrier for the rate‐controlled step (*CH 3 OC(O) 2 dissociation to *CH 3 OCO), thereby boosting the DMC yield. Our new findings provide valuable insights into surface engineering and active site modulation of cerium‐based catalysts, offering a viable pathway for green resource utilization of CO 2 .