The design and development of a high performance hydrogenation catalyst is an important challenge in the utilization of CO2 as resources. The catalytic performances of the supported catalyst can be effectively improved through the interaction between the active components and the support materials. The obtained results demonstrated that the oxygen vacancies and active Cu-0 species as active sites can be formed in the CeO2-delta-catalysts by the H-2 reduction at 400 degrees C. The synergistic effect of the surface oxygen vacancies and active Cu-0 species, and Cu-0-CeO2-delta interface structure enhanced catalytic activity of the supported xCu/CeO2-delta catalysts. The electronic effect between Cu and Ce species boosted the adsorption and activation performances of the reactant CO2 and H-2 molecules on the corresponding Cu/CeO2-delta catalyst. The Cu/CeO2-delta catalyst with the Cu loading of 8.0 wt% exhibited the highest CO2 conversion rate in the RWGS reaction, reaching 1.38 mmol.g(cat)(-1) min(-1) at 400 degrees C. Its excellent catalytic performance in the RWGS reaction was related to the complete synergistic interaction between the active species via Ce3+-square-Cu-0 (square: oxygen vacancy). The Cu/CeO2-delta composite material is a superior catalyst for the RWGS reaction because of its high CO2 conversion and 100% CO selectivity. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.