Enhanced Ni–Ce interactions to enable efficient low-temperature catalytic CO2 methanation

Abstract

Metal–support interfacial sites have been widely employed as active sites for CO₂ hydrogenation to enhance the catalytic performance. However, experimental identification of interfacial sites and determination of the origin of the activity enhancement by the interfacial sites remain a challenge. In this study, Ni/CeO₂ catalysts were synthesized via a continuous co-precipitation method in a T-shaped microchannel mixer to construct abundant Ni–CeO₂ interfaces. Compared to Ni/CeO₂ catalysts prepared by the conventional impregnation method, catalysts synthesized by the improved co-precipitation method showed much better activity and stability for CO₂ hydrogenation to methane, enabling efficient low-temperature catalytic CO₂ methanation. A series of structural characterization and temperature-programmed experiments revealed that the improved co-precipitation method promoted the formation of Ni–O–Ce interfacial sites, providing more number of active sites for H₂-assisted CO₂ activation and thereafter leading to an improved CO₂ methanation performance. This study provides an insight into interfacial sites in heterogeneous catalytic processes.