Mesostructured NiO–CeO2mixed oxides, with Ni loadings in the range 5–35 wt% (gNi/gCeO2), were synthesized by the hard template procedure using SBA-15 as the template. A hard-templated CeO2was also prepared and used as the support for depositing Ni (5–35 wt%) by impregnation. Two NiO–Al2O3catalysts were synthesized for comparison, by impregnating nickel on a commercial γ-alumina. All the samples were characterized by different techniques as to their chemical composition, structure, morphology, texture, and redox features. The catalytic performance was investigated in the CO2methanation reaction after mild reduction pretreatment (H2at 400 °C for 1 h). Catalytic testing was performed under atmospheric pressure, 300 °C, 72,000 cm3h−1gcat−1, and stoichiometric H2/CO2molar ratio. High catalytic activity, with CH4selectivity values ≥ 93 mol%, was obtained with the NiO–CeO2mixed oxides (CO2conversions up to 76 mol%). When γ-Al2O3was used as the support, catalysts with low activity (CO2conversion ≤ 20 mol%) were obtained. On selected samples, additional catalytic runs were also performed for reaction times up to 30 h or with a higher space velocity value. The catalytic results were explained by taking into account the role of the nickel-ceria interactions both during the reduction of NiO and in the reactants activation.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology