The First‐Principles Study on the Mechanism of the RWGS Reaction Catalyzed by Pt₁@CeO_2‐<i>_x</i>(110) Single‐Atom Catalyst

Abstract CeO 2 exhibits superior catalytic activity and selectivity in the reverse water–gas shift (RWGS) reaction when combined with transition metals. Herein, a density functional theory (DFT) study was conducted to systematically investigate the mechanism of the RWGS reaction catalyzed by a Pt 1 /CeO 2 ‐ x (110) single‐atom catalyst. The dominant pathways for the H 2 dissociation and the oxygen vacancy (VO) formation on Pt 1 /CeO 2 (110) surfaces, as well as for the H 2 dissociation on Pt 1 /CeO2‐ x (110) surfaces, were elucidated. The RWGS reaction pathways involving linear and bent CO 2 adsorption on the Pt 1 /CeO 2‐ x (110) surface were explored, including the conventional redox mechanism, formate (HCOO) pathway, and carboxyl (COOH) pathway. The COOH pathway for linearly adsorbed CO 2 (li‐CO 2 *→COOH*→CO*+OH*→CO*+H 2 O*) was found to be the most favorable route for CO production. The rate‐determining step of the overall reaction is the dissociation of COOH* (COOH*→CO*+OH*), which has a relatively low activation barrier of 0.65 eV. These findings not only provide valuable theoretical insights into the catalytic performance of CeO 2 ‐based materials in the RWGS reaction but also enhance the understanding of its reaction mechanisms.