Promoter effect of Ce and Pr on the catalytic stability of the Ni-Co system for the oxidative steam reforming of ethanol

Abstract

This article presents a study of the catalytic stability of Ni and Co mixed oxides promoted with 5wt% Ce or Pr in the oxidative steam reforming of ethanol (OSRE). The catalysts were obtained by the calcination of hydrotalcite-type precursors (HT) prepared by the co-precipitation method and the reconstruction of the HT phase in the presence of aqueous (Ce/Pr-EDTA) complexes. The solids were characterized by X ray-diffraction (XRD), surface area (BET), X-ray fluorescence (XRF), temperature-programmed reduction (TPR-H2), and temperature-programmed desorption of CO2 (TPD-CO2) and O2 (TPD-O2), and they were additionally evaluated in the OSRE for 100h. The stability tests indicate that the presence of rare earths promotes a reduction of the precursors of coke. These results evidence the fundamental role of the lattice oxygen and the reducibility of the oxide phases.