CO and CO2 methanation over Ni catalysts supported on CeO2, Al2O3 and Y2O3 oxides

Methanation of carbon oxides (CO and CO2) was studied over Ni-based catalysts supported on CeO2, Al2O3, and Y2O3 oxides. Catalysts were synthesized by solution combustion synthesis and characterized by N-2-physisorption, XRD, H-2-TPR, TEM, CO-chemisorption, UV-vis DRS, XPS, and CO2-TPD. The effect of reaction temperature (250-500 degrees C) was investigated under atmospheric pressure, space velocity (GHSV) of 10,000 h(-1), and stoichiometric reactants ratio of (H-2-CO2)/(CO + CO2) = 3. It can be concluded that the nature of Ni-support interactions played a crucial role in enhancing CO and CO2 hydrogenation at low reaction temperature. Ni/CeO2 catalyst deactivated rapidly due to coke deposition, while the formation of NiAl2O4 spinel explained the lower activity of the Al2O3-supported system. Activity data for Ni/Y2O3 catalysts were closely related to the degree of Ni dispersion as well as to the medium-strength basicity. Good anti-coking and anti-sintering ability were observed after 200 h of lifetime test.