Metal organic framework derived Ni/CeO2 catalyst with highly dispersed ultra-fine Ni nanoparticles: Impregnation synthesis and the application in CO2 methanation

Abstract CO2 methanation is a promising strategy to convert the greenhouse gas into synthetic natural gas, which is known as a clean fuel with higher energy density. Ni/CeO2 is one of the active catalysts for CO2 methanation reaction. However, Ni/CeO2 with conventional metal/support structure suffers from the problem of nanocrystal coarsening during high-temperature reaction and thus decreasing catalytic activity. In this work, a Ni/CeO2 catalyst with novel structure was designed and synthesized through impregnation of Ce-based metal organic framework (MOF) with Ni precursor followed by calcination process. Due to the confinement effect of ultra-small pores derived from the MOF, Ni/CeO2 catalysts with ultrafine Ni nanoparticles, high dispersion and good thermostability were resulted. Among all the samples, Ni/CeO2 calcined at 600 °C showed the best catalytic performance due to the highest amount of oxygen vacancies. This work demonstrates a facile way to synthesize a broad range of ultra-fine metal/metal oxide nanocomposite catalysts with high catalytic activity and good stability for various applications.