Performance of palladium and platinum supported on alumina pillared clays in the catalytic combustion of propene†
Abstract
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 °C, carbon dioxide physisorption at 0 °C, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), CO and H2 chemisorption at 35 °C, NH3 chemisorption at 70 °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.