Catalysts based on BaZrO3 with different elements incorporated in the structure I: BaZr(1−x)PdxO3 systems for total oxidation

Abstract New catalytic systems, synthesized by a variant of citrate route, are proposed for total oxidation reactions. They consist of solid solutions—barium, zirconium, palladium and oxygen—with a perovskite structure and a formula BaZr (1− x ) Pd x O 3 . Detailed analysis of the X-ray diffraction (XRD) diffractograms and the TGA cycles show that Pd is randomly distributed as Pd IV among the B sites of the perovskite, together with Zr. The full reduction of the catalyst is completed at around 1450 °C, whereas the re-oxidation of the reduced palladium occurs 150 °C—higher than for Pd IV supported on γ-alumina. The catalysts were tested for the catalytic combustion of methane; it was found that, although the catalysts tested were unsupported, the light-off temperature at 20% of methane conversion was roughly 400 °C. These preliminary results suggest that these systems might be suitable for both low and high temperature applications.