Reconstruction of interface oxygen vacancy for boosting CO2 hydrogenation by Cu/CeO2 catalysts with thermal treatment

The interfacial structure of metal and oxide support plays a pivotal role in reverse water gas shift (RWGS). However, rare work investigated the factor of the metal-oxide interface during RWGS reaction. In this work, the interface of Cu/CeO2 catalysts was designed through the thermal treatment of copper nitrate salt on CeO2 with an H2 atmosphere under different temperatures, and CO2 hydrogenation performance was studied at 400°C to investigate the effect of interfacial structure on RWGS reaction. Among these prepared catalysts, Cu/CeO2-400 catalysts achieved the best CO2 conversion activity (CO production rate 1.23 mol/gcat.h). Cu interacted with CeO2 to form Cu-O-Ce interface and induced more oxygen vacancy formation. The oxygen vacancy around the Cu-CeO2 interface enhanced CO2 adsorption and promoted CO2 conversion. CO2 reacted with active hydrogen to formate species (COOH), then COOH species dissociated into CO and OH adsorbed on the surface of Cu-CeO2. These results gave insights into the design of a highly effective catalyst for CO2 hydrogenation.