The bulk and supported perovskite-type catalysts for the CO2 reforming of methane: The effect of ceria and magnesia

Abstract

BackgroundThe bulk or supported nickel catalysts are active in the dry reforming of methane to produce syngas. The nickel-based catalysts are deactivated quickly due to the metal sintering and coke deposition. Perovskite catalysts are stable, enhance the dispersion of the active sites, and resist metal sintering and coke deposition. The coke deposition is inhibited by increasing the CO2 adsorption and oxidation of the deposited coke. MethodsA series of ceria-doped perovskite catalysts La1-xCexNiO3, LaNi1-xCexO3 and magnesia-modified-alumina supported perovskite-type catalysts were prepared via the sol-gel method. The prepared catalysts were thoroughly characterized via state-of-the-art characterization techniques. Significant findingsThe incorporation of ceria assisted the supported catalysts in forming a dispersed phase at low loading and forming other NiO or NiO-MgO (solid solution) NiAl2O4 and MgAl2O4 (spinel phase). The catalytic activity for the CO2 reforming of methane reaction increased with the addition of magnesia and the substitution of La-ion with tetravalent metal cation (ceria). The doping of ceria increased the stability of the catalyst. The bulk catalyst La0.5Ce0.5NiO3 exhibited promising catalytic activity. The magnesia-modified-alumina-supported catalyst (50La0.5Ce0.5NiO3/8MgO-Al2O3) was more active than the alumina-supported or bulk-perovskite catalysts with low coke deposition and higher percent conversion of CH4 (97%) and CO2 (99%) at 1073 K.