Highly dispersed Ni-based catalysts for CO2 methanation have been extensively studied over the last decade. However, a highly loaded Ni-based catalyst always results in a large Ni particle size and poor CO2 methanation activity. In this work, a colloidal solution combustion method was used to prepare a highly loaded Ni–La2O3 catalyst (50 wt % Ni) with a small Ni particle size and abundant metal–support interface. The characterizations demonstrated that a Ni–La2O3 catalyst prepared in this way has a mesoporous structure and a small Ni particle size. Due to the small Ni particle size and abundant metal–support interface, the highly loaded mesoporous Ni–La2O3 catalyst exhibits higher activity and selectivity in CO2 methanation compared to the Ni–La2O3 catalyst prepared by a conventional solution combustion method.

Ni-CeO2/SBA-15-V catalyst was prepared by the impregnation method with vacuum thermal treatment and used for CO2 methanation reaction. Compared with Ni-CeO2/SBA-15-air catalyst with thermal treatment in air, the reduced Ni-CeO2/SBA-15-V catalyst with vacuum thermal treatment exhibited higher Ni dispersion and smaller Ni particle size. In CO2 methanation reaction, the Ni-CeO2/SBA-15-V catalyst was more active and selective than the Ni-CeO2/SBA-15-air catalyst. The good activity and selectivity of Ni-CeO2/SBA-15-V catalyst should be due to highly dispersed Ni in contact with small CeO2 particles.