Transition metal doping effect and high catalytic activity of CeO2-TiO2 for chlorinated VOCs degradation

Abstract A series of transition metals (Fe, Co, Ni, Cu, Cr and Mn)-doped CeO2-TiO2 catalysts were prepared by the sol-gel method and applied for the catalytic removal of 1,2-dichloroethane (DCE) as a model for chlorinated VOCs (CVOCs). The various characterization methods (XRD, N2 adsorption-desorption, UV-Raman, NH3-TPD and H2-TPR) were utilized to investigate the physicochemical properties of the catalysts. The results show that doping Fe, Co, Ni or Mn can obviously promote the activity of CeO2-TiO2 mixed oxides for DCE degradation, which is related to their improved texture properties, acid sites (especially for strong acidity) and low-temperature reducibility. Particularly, CeTi-Fe doped with moderate Fe exhibits excellent activity for DCE degradation, giving a T90% value as low as 250 °C. More importantly, only trace chlorinated byproducts were produced during the low-temperature degradation of various CVOCs (DCM, TCE, CB) over CeTi-Fe1/9 catalyst with high durability.