Ni-catalysts obtained from silicate intercalated HTlcs active in the catalytic partial oxidation of methane: Influence of the silicate content

Ni-containing silicate catalysts obtained by decomposition of hydrotalcite-like compounds (HTlcs) were tested in the catalytic partial oxidation (CPO) of methane. The effect of the amount of silicates on the properties and performances of catalysts with different nickel load (Ni8Mg60Al32 and Ni2Mg66Al32) Was studied. Catalysts were characterized by X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), Temperature Programmed Reduction/Oxidation (TPR/O), H-2 chemisorption, N-2 adsorption/desorption at - 196 degrees C. The amount of silicates determined structural and textural properties of the catalysts forming the forsterite phase after thermal treatment. Increasing the silicate load, the specific Surface area (S-BET) and the Ni dispersion decreased, but the reducibility of Ni2+ species was not modified. Catalytic activity depended on the nickel load and the amount of silicate anions. Catalysts with high Ni content (Ni8Mg60Al32) were active and stable. Catalysts with low Ni load (Ni2Mg66Al32) showed good catalytic performances at the beginning of the tests; however, the samples with large silicate content deactivated by oxidation of Ni-0 particles. (C) 2009 Elsevier B.V. All rights reserved.