Structure and Activity Comparison of Cu/CeyZr1–yOx Series Catalysts in the Reverse Water–Gas Shift Reaction

Cu-based catalysts with abundant oxygen vacancies have attracted great attention for the reverse water–gas shift (RWGS) reaction because of their enhanced activity for CO2 adsorption and activation. However, the effect of the oxygen vacancy origin on the reaction and mechanism of RWGS are still unclear. Herein, various Cu/CeyZr1–yOx catalysts with different Ce/Zr ratios were designed and used for RWGS, and the results showed that the Cu/Ce0.9Zr0.1Ox catalyst exhibited the highest CO2 conversion (57.5%) and 100% CO selectivity. The characterization showed that Cu/Ce0.9Zr0.1Ox possessed highly dispersed Cu, abundant oxygen vacancies, and optimized basic sites, and the synergistic effect of the three factors led to the highest activity and stability. Both formate and carbonate pathways have been confirmed for Cu/CeyZr1–yOx, while the dominant reaction path is different between Cu/ZrO2 and Cu/CeO2.