Ni/zeolite X derived from fly ash as catalysts for CO2 methanation

A zeolite X synthesized from waste fly ashes from the energy sector was used as support in the preparation of Ni-catalysts for CO2 methanation. The catalysts were characterized by XRD, H-2-TPR, CO2-TPD and low-temperature nitrogen sorption techniques. At 450 degrees C CO2 conversions of around 50% were obtained, which are slightly under the range of conversions previously reported for similar Ni-catalysts prepared using commercial zeolites. The non-complete reduction of the Ni-phase, as a consequence of the relatively low reduction temperature chosen to preserve the zeolite structure, as well as the important contribution of strong basic sites, are most probably the two facts limiting the observed catalytic activity.