Effects of Ceria on Propane Reforming over Alumina Supported Palladium Catalysts

摘要

Propane oxidation was investigated over Pd/Al_2O_3 and Pd/CeO_2/Al_2O_3 catalysts. In fuel rich conditions, the results pointed us two discrete domains of reaction: oxidation in low temperatures (< 20% of propane conversion) and steam reforming of propane after oxygen has totally disappeared. In regard to Pd/CeO_2/Al_2O_3, the selective steam reforming reaction has showed the strong attendance of ceria. Large quantities of hydrogen have been evidenced where specific reactions were unchained. Our results also exhibited the influence of initial state of palladium on these reactions. Oxidative atmospheres inhibited propane oxidation besides increasing steam reforming temperatures. Moreover, these results showed a great ratio Pd~0/PdO, which maximizes catalytic activity for hydrocarbon oxidation.