Catalytic combustion of methane at high temperatures: Cerium effect on PdO/Al2O3 catalysts

PdO/Al2O3 and PdO/CeO2/Al2O3 catalysts were prepared in order to investigate the role of palladium precursors and cerium addition on the catalytic properties of these systems and on the thermal stability of PdO (active phase) in the catalytic combustion of methane at high temperatures (above 600 degrees C). The catalysts were obtained from different palladium precursors and presented distinct interactions with CeO2/Al2O3, thermal stability of PdO and catalytic activity. The use of cerium improved PdO thermal stability and the cerium effect was more pronounced on the catalyst prepared from acetylacetonate indicating that a PdO-CeO2 interaction is more favorable in this system. (C) 2009 Elsevier B.V. All rights reserved.