CO2 reforming of methane over nickel catalysts supported on nanocrystalline MgAl2O4 with high surface area

Abstract

In this paper dry reforming of methane (DRM) was carried out over nanocrystalline MgAl₂O₄-supported Ni catalysts with various Ni loadings. Nanocrystalline MgAl₂O₄ spinel with high specific surface area was synthesized by a co-precipitation method with the addition of pluronic P123 triblock copolymer as surfactant, and employed as catalyst support. The prepared samples were characterized by X-ray diffraction (XRD), N₂ adsorption, H₂ chemisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), temperature-programmed desorption (TPD) and transmission and scanning electron microscopies (TEM, SEM) techniques. The obtained results showed that the catalyst support has a nanocrystalline structure (crystal size: about 5 nm) with a high specific surface area (175 m²·g⁻¹) and a mesoporous structure. Increasing in nickel content decreased the specific surface area and nickel dispersion. The prepared catalysts showed high catalytic activity and stability during the reaction. SEM analysis revealed that whisker type carbon deposited over the spent catalysts and increasing in nickel loading increased the amount of deposited carbon. The nickel catalyst with 7 wt% of nickel showed the highest catalytic activity.