Comparative investigation of methane combustion over palladium-based catalysts supported on mesoporous MgAl2O4 and Al2O3

Abstract

A series of mesoporous Pd/Al2O3 and Pd/MgAl2O4 catalysts with different palladium contents (0.5, 1 and 4 wt%) were prepared by the impregnation method and used for methane combustion. Among the catalysts studied, 1Pd/MgAl2O4 (1 wt% Pd) was found to be highly effective for the catalysis of CH4 combustion below 450 °C, with a low apparent activation energy of ∼50.1 kJ/mol, and had good thermal stability. The characterization results showed that the excellent catalytic performance of Pd/MgAl2O4 can be ascribed to the strong interaction between the MgAl2O4 spinel and PdO species, favoring the dispersion and stability of the species. In addition, the effects of Pd particle size on CH4 combustion were also investigated. It was found that the catalytic activity of Pd/MgAl2O4, with a strong metal-support interaction, showed a volcano-shaped dependence on the size of Pd particles.