Study of Catalytic Methane Oxidation Over Pd Supported on Nanocrystalline CeO₂: Effects of Calcination and Pd Loading

Abstract

The catalytic oxidation of methane was studied over palladium supported on nanocrystalline ceria. Three palladium weight loadings (1, 5, and 10 wt%) were tested after calcining at 500 °C, at 280 °C and after no calcination at all. For the 5 and 10 wt% loadings, the 280 °C-calcined and non-calcined catalysts exhibit enhanced activity after several heating and cooling cycles. Calcining these same catalysts at 500 °C results in a systematic decline in activity. For all pretreatments the 1 wt% Pd catalyst exhibits decreasing activity. For the 5 and 10 wt% Pd loadings, the non-calcined catalysts are more active than the 280 °C-calcined catalysts, which are more active than the 500 °C-calcined catalysts. For the 1 wt% Pd catalyst, the opposite is true. The catalyst activity improves as the Pd loading is increased.

Unique Features and Properties of Nanostructured Materials

“…For several systems it was found that the influence of the substrate material on the catalytic performance in gas reactions, such as complete oxidation of methane, can be quite drastic. [30][31][32] Another application of the surface reactivity of nanocrystalline oxides is in gas sensing devices.…”