Support effect of zeolite on the methane combustion activity of palladium

Catalytic combustion of methane was carried out over Pd loaded on MFI and MOR zeolites. The activity and durability of the catalysts in the methane combustion was dependent on the Al concentration, the kind of cation and the structure of zeolite supports. Especially, Pd loaded on MOR was more active than that on MFI. The catalytic performance of Pd was correlated with the measurement of reaction order, activation energy and local structure of Pd determined by Pd K-edge EXAFS. A significant difference in the state of Pd was observed between MFI and MOR, where the Pd metal and PdO existed during the reaction over MOR and MFI, respectively. The high activity of Pd/MOR for methane combustion was ascribed to the generation of a mixture of Pd metal and PdO during the reaction. (C) 2003 Elsevier Science B.V. All rights reserved.