Ni nanocatalysts supported on mesoporous Al 2 O 3 -CeO 2 for CO 2 methanation at low temperature.

The selectivity and activity of a nickel catalyst for the hydrogenation of carbon dioxide to form methane at low temperatures could be enhanced by mesoporous Al 2 O 3 -CeO 2 synthesized through a one-pot sol-gel method. The performances of the as-prepared Ni/Al 2 O 3 -CeO 2 catalysts exceeded those of their single Al 2 O 3 counterpart giving a conversion of 78% carbon dioxide with 100% selectivity for methane during 100 h testing, without any deactivation, at the low temperature of 320 °C. The influence of CeO 2 doping on the structure of the catalysts, the interactions between the mesoporous support and nickel species, and the reduction behaviors of Ni 2+ ions were investigated in detail. In this work, the addition of CeO 2 to the composites increased the oxygen vacancies and active metallic nickel sites, and also decreased the size of the nickel particles, thus improving the low temperature catalytic activity and selectivity significantly.