Methanation of carbon dioxide over nickel-based Ce0.72Zr0.28O2 mixed oxide catalysts prepared by sol-gel method

Ni-Ce0.72Zr0.28O2 catalysts containing up to 15 wt% Ni were prepared, characterized and their catalytic activity was investigated in carbon dioxide methanation. The impact of the pre-treatment and the gas hourly space velocity were also studied. NiO dispersion and part of its incorporation into the mixed oxide lattice obviously increased the activity and stability of the catalysts. Very high CO2 conversions were achieved at 350 and 400 degrees C, together with extremely high selectivity to methane (>98%) for all catalysts. Finally, high stability on stream toward deactivation was observed up to 150 h at 350 degrees C. 10 wt% NiCe0.72Zr0.28O2 was found to be the optimal catalyst. (C) 2009 Elsevier B.V. All rights reserved.