Influence of zirconia addition in TiO2 and TiO2–CeO2 aerogels on the textural, structural and catalytic properties of supported vanadia in chlorobenzene oxidation

Abstract

This paper studies the effect of the direct incorporation of ZrO₂ in TiO₂ and TiO₂–CeO₂ aerogel supports prepared by sol–gel route on the physico–chemical and catalytic properties of supported vanadia catalysts in the total oxidation of chlorobenzene. The obtained catalysts have been characterized by means of ICP-AES, N₂ adsorption–desorption at 77 K, XRD, XPS, H₂-TPR and NH₃-TPD. The results revealed that Zr-doped V₂O₅ based catalyst is beneficial for the improvement of catalytic properties in chlorobenzene total oxidation. In particular, in the absence of cerium groups, this beneficial effect is correlated with the better acidic properties or/and the stabilization of the V₂O₅ active phase in a higher oxidation state. However, in the case of cerium rich catalyst, this positive effect is much stronger thanks to the enhanced redox properties of V₂O₅/TiO₂–CeO₂–ZrO₂.