Steam CO2 reforming of methane over La1−xCexNiO3 perovskite catalysts

Steam CO2 reforming of methane was carried out over cerium substituted perovskite catalysts. Among the catalysts studied, La0.9Ce0.1NiO3 showed the best performance with 49% of methane and 14% of CO2 conversion under the tested conditions. The chemical and structural properties of the catalysts before and after the reaction were studied by N2 physisorption, X-ray diffraction, CO2-TPD, TPH, TPR, TGA and TEM. It was found that most of Ce existed as CeO2 rather than being incorporated in perovskite lattice because of large difference in ionic radii between La3+ and Ce4+. Few substitution of Ce in A site resulted in high degree of reduction for active Ni species with good catalytic activity which was further decreased with increasing Ce concentration; substitution of large amount of Ce species led to methanation of CO2 and formation of large nickel cluster. TPH and TGA analysis revealed that Ce substituted catalyst has better resistance to coke deposition compared to non-promoted perovskite catalyst.