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

Abstract

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 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.