CeO2-assisted Ni nanocatalysts supported on mesoporous γ-Al2O3 for the production of synthetic natural gas

Abstract

Ni–Ce oxides (NiO–xCeO2/γ-Al2O3) supported on mesoporous γ-alumina with various mass percentage contents of CeO2 (x=0, 1, 2, 3, 4 and 5) were prepared through co-impregnation with citric acid. The influences of CeO2 content on the catalyst structure, surface characteristics, interaction between Ni species and the support, reducibility of Ni2+ ions and Ni particle dispersion were investigated in detail. The Ni–Ce oxides were highly dispersed on mesoporous γ-alumina and producing uniform Ni nanoparticles throughout γ-alumina frameworks after H2 reduction. The addition of CeO2 could lower metallic Ni particle sizes and generate oxygen vacancies. The reduced Ni–xCeO2/γ-Al2O3 catalysts were investigated for their catalytic behaviors in CO2 methanation and exhibited excellent catalytic performance at low temperature in the range of 150–350°C. Equilibrium conversion of CO2 was achieved at a low temperature of 300°C over the optimal CeO2 content of 3wt%.