Total oxidation of volatile organic compounds by vanadium promoted palladium-titania catalysts: Comparison of aromatic and polyaromatic compounds

Vanadium oxide, palladium oxide and mixed Pd/V-supported on titania catalysts have been prepared and tested in the total oxidation of volatile organic compounds (VOCs). A comparative study with two different aromatic VOCs (benzene and naphthalene) has been carried out. For benzene, the mixed Pd/V-catalysts presented the highest catalytic activity. However, whilst studies with benzene led to the formation of CO2 only, the total conversion of naphthalene to CO2 was not achieved throughout the full temperature range for naphthalene conversion. A naphthalene conversion to CO2 of 99% was obtained over Pd/TiO2, V/TiO2 and Pd/V/TiO2 catalysts at 275, 325 and 300 °C, respectively. Therefore, the requirements for an effective benzene total oxidation catalyst cannot be readily extrapolated to larger polycyclic aromatic compounds, as in the naphthalene oxidation the most active catalyst from an environmental point of view is Pd supported on TiO2.