The Role of Catalyst Properties on Methanol Oxidation over V2O5-TiO2 Using Ozone

Oxidation of methanol over V2O5 catalysts supported on anatase TiO2 that were prepared using sol-gel formation and impregnation procedures were investigated. The effects of incorporating Mg in sol-gel to influence the properties of the catalyst were also studied. The process provides an alternative low temperature reaction pathway for reducing emissions of hazardous air pollutant (HAPs) such as methanol and total reduced sulfur compounds (TRS) from pulp and paper mills. The bulk and surface composition of the catalysts were determined by XRD and SEM-EDAX, respectively. The X-ray diffraction patterns of the vanadia-titania catalysts showed mainly the anatase phase of TiO2. Temperature programmed desorption of methanol from the different catalyst showed that the α and β peaks differ significantly with V content and addition of Mg. The combination of gas phase and surface reactions on the V/TiO2 catalysts reduced the amount of ozone required for high degradation of methanol to mainly COx with small quantities of methyl formate. In the absence of ozone the catalysts showed very low activity. It is hypothesized that the ozone is directly influencing the V4+ and V5+ redox cycle of the catalyst. Oxidation of methanol is influenced by the operation variables and catalyst properties. The results of this study revealed that the V content has significant influence on the catalyst activity, and the optimum vanadia loading of about 6 wt%. Higher turnover frequencies were observed over sol-gel catalysts than with catalysts prepared by the impregnation method