Catalytic oxidation of VOCs on Au/Ce-Ti-O

CexTi1-xO2 oxides have been synthesised by sol-gel method with x varying from 0 to 0.3 and characterised by XRD and TPR. The structure of oxides changes with the Ce/Ti molar ratio. The presence of ceria in Ce-Ti oxides inhibits the phase transition from anatase to rutile. When x = 0.3 (Ce0.3Ti0.7O2 sample), the solid presents an amorphous state. The TPR results indicate that the presence of Ti enhances the reducibility of cerium oxide species. Catalytic oxidation of propene is investigated on Ce-Ti oxides and the better conversion is obtained with Ce0.3Ti0.7O2 but the CO2 selectivity reaches 63% at 400 degrees C. Gold is then deposited on theses oxides to improve the catalytic activity. On the basis of characterisation data (HZ TPR), it has been suggested that gold influences the reduction of the Ce-Ti oxide support and the catalytic activity to the propene oxidation. Thus, Au/Ce-Ti-O system catalysts are promising catalysts for propene oxidation. (C) 2007 Elsevier B.V. All rights reserved.