Fig. 7. The proposed reaction pathways for the RWGS reaction on the copper‒ceria catalyst.

a Chemisorption of CO₂ on the 10Cu/CeO₂{111} surface. Five oxygen vacancies, named after V_O-A to V_O-E, were made comparisons, and the selected CO₂ was located close to V_O-A; b The adsorption energy that CO₂ was bound to V_O on the CeO₂{111} surface was obviously weaker than those of Cu dropped ceria sites; c RWGS reaction mechanism occurred in the V_O-A. The red, blue, and black lines indicated different reaction paths, and the structural diagrams with the red, blue or black stroke corresponded to the reaction paths, respectively.