The state of BEA zeolite supported nickel catalysts in CO2 methanation reaction

Two model nickel catalysts for CO2 methanation reaction were prepared by the impregnation method using unmodified and dealuminated BEA-type zeolite supports, denoted NiHAlBEA NiSiBEA. Transmission electron microscopy (TEM) X-ray diffraction studies evidenced formation of metallic crystallites different size, partially located on external surface grains in catalyst small nanoparticles uniformly distributed within NiSiBEA catalyst. Higher conversion selectivity towards methane at low temperatures observed This showed an improved resistance sintering high temperatures. The decrease with time stream, accompanied drop was attributed to increase Ni crystallite resulted from migration inner subsequent agglomeration. Diffuse reflectance infrared Fourier transform, quasi in-situ photoelectron spectroscopy presence their partial reoxidation under conditions. High dispersion led retardation deactivation H2S.