Low temperature catalytic combustion of 1,2-dichlorobenzene over CeO2-TiO2 mixed oxide catalysts

Ce1-xTixO2 mixed oxide catalysts with various Ti/Ce+Ti ratios were prepared by sol-gel way and used in catalytic combustion of 1,2-dichlorobenzene (o-DCB). Characterization by XRD, Raman, HRTEM, XPS, H-2-TPR, O-2-TPD, CO2-TPD and NH3-TPD revealed that Ce1-xTixO2 catalysts were identified as the forms of fluorite, monocline and anatase. The incorporation of Ti distorted the crystal structure and thus increased greatly the acidity and the oxygen mobility at high temperature. Ce1-xTixO2 catalysts had considerable activity for o-DCB combustion. TOF obtained on the catalyst with Ti/Ce+Ti ratio of 0.1 at 275 degrees C reached the highest value of 0.64 mu mol/min m(2) (Ti). Ti improved the stability of Ce1-xTixO2 catalysts through retarding the exchange of Cl for basic lattice oxygen and hydroxyl groups. High stability maintained at 330 degrees C for at least 50 h. In situ FTIR indicated that o-DCB adsorption was much stronger on Ti species than Ce species and different reaction pathways were related to different types of oxygen species existing on the surface of Ce1-xTixO2 catalysts. (C) 2015 Elsevier B.V. All rights reserved.