Enhanced performance of low Pt loading amount on Pt-CeO2 catalysts prepared by adsorption method for catalytic ozonation of toluene

The supported catalyst of Pt-CeO2/BEA with low loading amount (0.07 wt%) of Pt nanoparticles presented competitive performance towards catalytic ozonation of toluene. Characterization results demonstrated that the improved activity could be attributed to the enhanced Pt-CeO2 strong metal-support interaction induced by the formation of much smaller, more uniform and dispersive Pt nanoparticles through the adsorption method. Furthermore, Pt/CeO2 and Pt/SiO2 were employed to elucidate the intrinsic reasons for the activity improvement. Various techniques such as XPS, Raman, O2-TPD, etc. were performed to characterize the physicochemical properties. Results showed that the anchoring effect for Pt nanoparticles by the Pt-O-Ce bonds, greater amount of oxygen vacancies and more generated peroxide species are potentially responsible for the improvement of catalytic performance. In-situ Raman confirmed the participation of peroxide species in toluene oxidation, which were previously formed during the ozone decomposition. Plausible reaction pathways for the involving reactions on catalyst surface were also proposed.