Abstract: Catalytic behavior for syngas methanation over nickel-based catalysts with different supports (Al₂O₃-1, Al₂O₃-2, and SiO₂) was investigated. The results showed that the catalyst prepared by Al₂O₃-2 or SiO₂ support possessed higher activity and stability, while the stability of Ni/Al₂O₃-1 catalyst was extremely poor. The catalysts were characterized by X-ray powder diffraction, transmission electron microscopy, temperature-programmed reduction, N₂ adsorption-desorption, and thermogravimetry. Characterization results showed that carbon deposition is not a key factor in determining the catalyst stability, while the destruction of support structure and the migration and agglomeration of Ni particles during the reaction may be the main reasons for the rapid deactivation of the Ni/Al₂O₃-1 catalyst.

Key words: syngas, methanation, nickel-based catalyst, alumina, silica, stability