Performance of palladium and platinum supported on alumina pillared clays in the catalytic combustion of propene

The effect that the metal content of various pillared-clay-supported catalysts may have on the oxidation of propene was studied in this work. For this purpose, an alumina pillared montmorillonite (Al-PILC) was used as a support for palladium and platinum. The catalysts, with metal loadings of between 0 and 2 wt%, were characterized by chemical analysis, nitrogen physisorption at -196 degrees C, carbon dioxide physisorption at 0 degrees C, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), CO and H-2 chemisorption at 35 degrees C, NH3 chemisorption at 70 degrees C and temperature-programmed reduction (TPR). Bulk PdO, Pd, and palladium-alumina structures were detected for the palladium catalysts. Likewise, bulk PtO2 and small PtO2 particles, which partially interact with the support, were observed for the Pt/Al-PILC catalysts. The results obtained suggest that the propene oxidation over Pd/Al-PILC and Pt/Al-PILC is a structure sensitive reaction as the turnover frequencies are affected by metal dispersion and the structure of the surface catalysts.