Catalytic activity and characterizations of Ni/K2TixOy-Al2O3 catalyst for steam methane reforming

Nickel catalysts supported on the K2TixOy Al2O3 were prepared by the wet impregnation method for steam methane reforming to produce hydrogen. X-ray diffraction, N2 physisorption, scanning electron microscopy with energy dispersive spectroscopy, the H2 temperature-programed reduction technique, and X-ray photoelectron spectroscopy were employed for the characterization of catalyst samples. The results revealed that the performance of the Ni/K2TixOy Al2O3 catalysts was comparable to that of commercial FCR-4 for steam methane reforming under the mild condition. In particular, a catalytic stability test at 800 C and in the reactant flow with the steam-to-carbon (S/C) feed ratio of 1.0 indicated that the Ni/K2TixOy Al2O3 catalysts were more active, thermally stable and resistant to deactivation than the non-promoted Ni/Al2O3. It is considered that the appropriate interaction strength between nickel and the modified support and proper K2TixOy phases with a surface monolayer coverage achieved at ca. 15 wt.% loading in the support play important roles in promoting the steam methane reforming activity as well as suppressing the sintering of the catalyst. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.