The promotion effect of tungsten on monolith Pt/Ce0.65Zr0.35O2 catalysts for the catalytic oxidation of toluene

Abstract

A mesoporous Ce_0.65Zr_0.35O₂ support was synthesized via co-precipitation, and Pt/Ce_0.65Zr_0.35O₂ and Pt-WO₃/Ce_0.65Zr_0.35O₂ catalysts were prepared through the incipient-wetness impregnation method for the catalytic oxidation of toluene. As evidenced by the catalytic activity results, the temperature for the complete conversion of toluene using the monolith Pt-WO₃/Ce_0.65Zr_0.35O₂ catalyst decreased by about 30 °C compared to that using Pt/Ce_0.65Zr_0.35O₂. In addition, the physicochemical properties of the catalysts were characterized via N₂ adsorption–desorption, XRD, H₂-TPR, XPS and NH₃-TPD experiments. The in situ DRIFTs technique was used to study the toluene catalytic oxidation process. The results showed that the excellent catalytic activity of Pt-WO₃/Ce_0.65Zr_0.35O₂ is ascribed to its good low-temperature reducibility, higher surface-adsorbed oxygen concentration, and greater medium strength acidity.