Catalytic Oxidation of -Decane, -Hexane, and Propane over Pt/CeO Catalysts.

Pt species with different chemical states and structures were supported on CeO by solution reduction (Pt/CeO-SR) and wet impregnation (Pt/CeO-WI) and investigated in catalytic oxidation of -decane (CH), -hexane (CH), and propane (CH). Characterization by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, H-temperature programming reduction, and oxygen temperature-programmed desorption showed that Pt and Pt existed on Pt nanoparticles of the Pt/CeO-SR sample, which promoted redox, oxygen adsorption, and activation. On Pt/CeO-WI, Pt species were highly dispersed on CeO as the Pt-O-Ce structure, in which surface oxygen decreased significantly. The Pt/CeO-SR catalyst presents high activity in oxidation of CH with a rate of 0.164 μmol min m at 150 °C. The rate increased with oxygen concentration. Moreover, Pt/CeO-SR presents high stability on feed stream containing 1000 ppm CH at gas hour space velocity = 30,000 h as low as 150 °C for 1800 min. The low activity and stability of Pt/CeO-WI were probably related to its low availability of surface oxygen. In situ Fourier transform infrared results showed that the adsorption of alkane occurred through the interaction with Ce-OH. The adsorption of CH and CH was much weaker than that of CH, which resulted in the decrease in activity for CH and CH oxidation of Pt/CeO catalysts.