Effect of support on V2O5 catalytic activity in chlorobenzene oxidation

Abstract

The present paper investigates the influence of the direct incorporation of ceria in TiO2 aerogels support (sulfated and unsulfated) prepared by a sol–gel route on the catalytic properties of vanadia based materials in the total oxidation of chlorobenzene. ICP-AES, N2 physisorption, XRD, DRIFTS, Raman spectroscopy, XPS, H2-TPR and NH3-TPD were employed for catalyst characterization. This study demonstrated that cerium oxide is present as CeO2 form at the catalyst surface, which can improve the catalyst redox properties and so enhance the catalytic activity at high temperature (400°C). Besides, sulfate containing vanadia–titania samples (doped or not with ceria) had their catalytic performances considerably improved (due to sulfates) at lower temperatures (range 200–300°C). This is due to an increased global acidity and higher reactivity of redox sites thanks to the superficial interaction between (i) vanadia and sulfate, and (ii) when ceria is present, between ceria and sulfate leading to higher efficiency of catalysts in the chlorobenzene oxidation.