Catalytic oxidation of volatile organic compounds on manganese and copper oxides supported on titania

A series of mixed oxides supported on TiO2 (Mn1-yCuyOx/TiO2) synthesized by incipient wetness impregnation method have been characterized and tested for toluene oxidation volatile organic compounds (model). For all catalysts, the total conversion (100%) of toluene into CO2 was obtained at temperatures higher than 240 degrees C with no catalyst deactivation. At lower temperatures, a gradual deactivation was observed. The most efficient catalyst was Mn0.5Cu0.5Ox/TiO2 (noted MnCuOx/T). Several characterization techniques, XRD, TPR, BET, and TG/DT analysis, were used to explain the catalytic performances. The results allowed attributing the higher activity of MnCuOx/T to the formation of Mn1.6Cu1.4O4 spinel phase. It has been also demonstrated that the mobility of the catalyst network oxygen is a determining parameter of the catalytic activity. The decrease of activity at a low temperature is related to the adsorption of high molecular weight carbonaceous compounds. However, the catalytic activity is easily regenerated by heating in air flow at 300 degrees C. (C) 2008 American Institute of Chemical Engineers.