Role of oxide support in Ni based catalysts for CO 2 methanation.

The CO 2 methanation reaction of reduced and unreduced Ni based CeO 2 , Al 2 O 3 , TiO 2 and Y 2 O 3 supported catalysts was investigated. The Ni/CeO 2 and Ni/Y 2 O 3 catalysts exhibited similar CO 2 conversions at all reaction temperatures. The catalysts were studied by X-ray diffraction (XRD), H 2 chemisorption, H 2 temperature-programmed reduction (TPR), and in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS); the results suggested that the reducibility of both metal and support at low temperature, strong metal support interaction and small Ni particle size are important factors for low-temperature CO 2 methanation. Based on the DRIFT studies, the difference in the CO 2 adsorption properties and reaction pathway depending on the reduced and unreduced Ni based supported catalysts was discussed.