Control of Ni/Ce1-xMxOy catalyst properties via the selection of dopant M = Gd, La, Mg. Part 1. physicochemical characteristics

Abstract

To develop effective reforming catalyst a series of Ni catalysts (Ni content 2‒15 wt.%) supported on ceria-based oxides Ce1-xMxOy were synthesized by incipient wetness impregnation. To regulate dispersion and reducibility of the active component, the variation of chemical composition of support was performed. The prepared samples of supports and catalysts were characterized by X-ray spectral fluorescence analysis, N2 adsorption/desorption, X-ray diffraction, transmission electron microscopy, and thermal analysis. It was found that the support composition specified the forms of stabilization (NiO or Ni-M-O oxides, M = La, Mg) and capability to reduction of Ni-component through the realization of a different extent of interaction between Ni-containing species and support. The increase of M content in CexM1-xOy support induces the decrease of CexM1-xOy crystallite size, improvement of Ni active component dispersion and the increase of hard-to-reduce portion of nickel cations due to the growth in the degree of nickel-CexM1-xOy interaction. The identified variation of the textural, structural and redox characteristics of the Ni/CexM1-xOy catalysts should influence their performance in the catalytic process.