Influence of the nature of titanium source and of vanadia content on the properties of titanium-pillared montmorillonite

Vanadia supported on titanium (Ti)-pillared montmorillonite, issued from different Ti-precursors, have been prepared and characterized. The physico-chemical properties of vanadia-doped Ti-pillared clays depend mainly on the nature of Ti-alkoxide precursor. Higher surface areas and the presence of mesoporosity in the Ti-pillared clay samples are due to the organic polyoxycations intercalated between the clay layers. Surface areas diminish with the increase of vanadia content but remain very high in the case of the samples prepared from Ti(OCH3)4 or Ti(OC2H5)4 precursors. In the selective catalytic reduction (SCR) of NO by NH3, the activity necessitates a good balance between acidic and redox properties. Our results show that the nature of Ti-alkoxide precursor and the dispersion of vanadium are the key factors for obtaining this activity.