Construction of surface active centers on the mesoporous Co/CeO2-δcatalysts for CO2 hydrogenation

The surface active centers, which include metal Co, surface oxygen vacancies, and Co-0 CeO2- delta interface structures, can be constructed on the mesoporous Co/CeO2- delta catalysts by wet impregnation method. And the surface active centers can be regulated by the Co species dosage. The interaction between the metal Co and CeO2- delta can promote surface oxygen vacancies and Co-0-CeO2- delta interface structures to be formed and be conducive to inhibit the aggregation and sintering of Co species in high temperature environment. The prepared Co/CeO(2- delta)catalysts have better catalytic performances for CO2 hydrogenation than the single component Co and CeO2- delta catalysts, which can be attributed to the synergistic effect between Co-0 active centers, surface oxygen vacancies, and Co-0-CeO(2- delta)interface structures. Therefore, the Co/CeO2- delta catalysts have strong adsorption and activation ability for reactant CO2 and H-2 molecules to improve the CO2 hydrogenation activity. At atmospheric pressure and 400 degrees C, the CO2 conversion and CH4 selectivity on the Co/CeO2- delta catalyst with Co loading of 12% could reach 59.7% and 95.7%, respectively, and maintained good stability in 9 cycles for CO2 hydrogenation reaction.