Investigation of mesoporous NiAl2O4/MOx (M = La, Ce, Ca, Mg)-γ-Al2O3 nanocomposites for dry reforming of methane

One- pot synthesized mesoporous NiAl2O4/gamma-Al2O3 and NiAl2O4/MOx (M = La, Ce, Ca, Mg)-gamma-Al2O3 nanocomposites with excellent textural properties were employed for the dry reforming of methane (DRM). NiAl2O4/La2O3/gamma-Al2O3-imp prepared via a traditional impregnation method was used for comparison. The promotion effect of modifiers on the physicochemical properties and catalytic performance of the catalysts was systematically investigated. Characterization and evaluation results indicated that the modified catalysts showed higher activities and better coking-resistance than Ni/gamma-Al2O3, and Ni/La2O3-gamma-Al2O3 was found to be the most effective one. All the catalysts with or without modifiers presented similar Ni particle sizes due to the enhanced metal-support interaction derived from the reduction of the NiAl2O4 precursor. However, more medium-strength basic sites on the catalyst surface were obtained by adding promoters, which could facilitate the adsorption/activation of CO2 and the gasification of amorphous carbon, improving the catalytic properties and accelerating the coke elimination rate. Additionally, the incorporation of promoters also prevented the phase transformation of gamma-alumina.