Elaboration and characterization of sulfated and unsulfated V2O5/TiO2 nanotubes catalysts for chlorobenzene total oxidation

Abstract

This paper examines the use of TiO2 nanotubes (HNTs) as supports for V2O5 based catalysts in the total oxidation of chlorobenzene. The effect of the addition of SO42- onto the support is also discussed. Vanadium was introduced either by direct incorporation of V during the elaboration of the nanotubes (in situ elaboration), or by the impregnation of V on the surface of the supports (ex situ elaboration). The obtained catalysts have been characterized by means of ICP-AES, N2 adsorption-desorption at 77K, XRD, DRIFTS, XPS, H2-TPR and NH3-TPD. We demonstrated that sulfating step highly improves the catalytic performances of V-HNTs catalysts. This is due to an increased global acidity and a higher reactivity of redox sites thanks to the electronic interaction between sulfated titania and VOx species. Moreover, it seems that the 'in situ' or 'ex situ' elaboration route of sulfated V-catalysts influences the environment of vanadium species. In particular, the 'in situ' route leads to a more efficient catalyst. © 2013 Elsevier B.V.