Porous NiO Prepared by Flame Spray Pyrolysis for 80 wt% Ni–CeO₂ Catalyst and Its Activity for CO₂ Methanation

NiO and CeO2 were prepared via flame spray pyrolysis. The specific surface area total pore volume 251 m2 g–1 2.3 cm3 for 338 3.3 CeO2, respectively. high porosity of the allowed deposition small particles (∼5 nm) by impregnation cerium acetate monohydrate. reduced using 5 % H2 at 500 °C 1 h which converted to metallic Ni. During reduction, growth Ni was hindered particles. Consequently, size relatively (∼20 despite extremely content (80 wt%), as observed scanning transmission electron microscopy. In contrast, incorporation nickel tetrahydrate into support resulted in formation inhomogeneous (20-100 after reduction. chemisorption measurement showed former catalyst 13.7 g–1, 2.4 times larger than that latter catalyst. exhibited remarkable performance CO2 methanation (47 conversion 250 °C), 2 higher