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

A series of transition metals(Fe,Co,Ni,Cu,Cr and Mn)-doped CeO2-TiO2catalysts 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 including X-ray diffraction(XRD),N2adsorption-desorption,UV-Raman,NH3temperature-programmed desorption(NH3-TPD) and H2temperature-programmed reduction(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-TiO2mixed 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 1,2-dichloroethane(DCE) degradation,giving a T90%value as low as 250℃.More importantly,only trace chlorinated byproducts were produced during the low-temperature degradation of various CVOCs(dichloromethane(DCM),trichloroethylene(TCE) and chlorobenzene(CB)) over CeTi-Fe1/9 catalyst with high durability.