Stability improvements of Ni/α-Al2O3 catalysts to obtain hydrogen from methane reforming

Ni catalysts supported on commercial alpha-Al2O3 modified by addition of CeO2 and/or ZrO2 were prepared in the present work. Since the principal objective was to evaluate the behavior of these systems and the support effect on the stability, methane reforming reactions were studied with steam, carbon dioxide, partial oxidation and mixed reforming. Results show that catalysts supported on Ce-Zr-alpha-Al2O3 composites present better reforming activity and stability noticeably higher than in the case of the reference support. With respect to composites, the presence of mixed oxides of CexZr1-xO2 type facilitates the formation of active phases with higher interaction. This fact reduces the deactivation by sintering conferring to the system a higher contribution of adsorbed oxygen species, favoring the deposited carbon elimination. These improvements resulted in being dependent on the Ce:Zr ratio of the composite, thus obtaining more stable catalysts for Ce:Zr = 4:1 ratios. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved