Methane combustion over Pd/Ni-Al oxide catalysts: Effect of Ni/Al ratio in the Ni-Al oxide support

We prepared xNi-2Al oxide (x=0-1.1) supports via a hydrothermal method, and applied Pd/xNi-2Al catalysts in the catalytic methane combustion reaction. It was found that the physicochemical properties of the xNi-2Al supports varied as a function of the Ni content, and the interaction between support and impregnated Pd was also influenced by the Ni content. Furthermore, variation in the Ni content significantly affected the chemical state and reducibility of the impregnated Pd species. Finally, the catalytic activity and stability of prepared Pd/xNi-2Al catalysts in the methane combustion reaction exhibited a volcano-shaped curve as a function of Ni content, with a maximum being observed for the Pd/1.0Ni-2Al catalyst, which corresponded to the highest Pd2+ composition and reducibility.