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

Abstract

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.