Studies on the steam CO2 reforming of methane over ordered mesoporous nickel–magnesium–alumina catalysts

Abstract

Ordered mesoporous materials have received much attention because of their high surface area and ordered pore structure. The Mg-promoted ordered mesoporous nickel–alumina catalysts (M-Mg x NA), which were prepared using the evaporation induced self-assembly method, were investigated in the Steam CO2 Reforming (SCR) of methane. The fresh and spent catalysts were characterized by various analytical techniques such as N2 physisorption, small-angle X-ray scattering, X-ray diffraction, temperature-programmed reduction, thermogravimetric analysis, transmission electron microscopy and CO2-temperature programmed desorption analysis. We have found that the M-Mg x NA catalyst has a larger surface area and a narrower pore size distribution than the Ni/Al2O3 catalyst (NA); furthermore, the M-Mg x NA catalyst exhibits high catalytic stability under the tested conditions of 600 °C, 1 bar and feed molar ratio of CH4:CO2:H2O = 1:1:1. We consider that the ordered mesoporosity prevents the nickel particles from sintering because of the confinement effect and decreases the particle size in the SCR reaction. Thus, the Mg-promoted ordered mesoporous nickel-alumina catalyst shows enhanced resistance to carbon formation during the steam CO2 reforming of methane.