Catalytic combustion of methane. A case study: Pd/CeO2 catalysts

Sara Colussi
Dipartimento di Scienze e Tecnologie Chimiche, Università di Udine

Abstract:
Catalytic combustion of methane has been widely studied as a valid alternative to thermal combustion for energy production and for exhausts aftertreatment in natural gas fuelled vehicles. Palladium-based catalysts are the most active materials for the combustion of methane. Their efficiency is strongly influenced by the dynamics of PdO-Pd transformation, PdO being the active phase. It has been reported that PdO stability can be improved by the addition of cerium oxide, that acts as a promoter on Pd reoxidation. In the last few years our work has been focused on the study of the promoting and stabilizing effect operated by CeO2 on Pd-based catalysts. Different experimental techniques have been used in order to understand and to explain the nature of Pd/CeO2 interaction. Our results indicate that Pd-PdO redox mechanism on alumina support in the presence of CeO2 is associated with a geometrical contact between CeO2 and Pd particles. Our studies allow to draw a more complete picture of the Pd-PdO redox behavior.