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

A series of mesoporous Pd/Al 2 O 3 and Pd/MgAl 2 O 4 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/MgAl 2 O 4 (1 wt% Pd) was found to be highly effective for the catalysis of CH 4 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/MgAl 2 O 4 can be ascribed to the strong interaction between the MgAl 2 O 4 spinel and PdO species, favoring the dispersion and stability of the species. In addition, the effects of Pd particle size on CH 4 combustion were also investigated. It was found that the catalytic activity of Pd/MgAl 2 O 4 , with a strong metal-support interaction, showed a volcano-shaped dependence on the size of Pd particles.