Investigation of V2O5/gamma-Al2O3 catalysts by FTIR

In this study the V2O5/Y-Al2O3 catalysts were prepared by the grafting method. Their Bronsted and Lewis acid sites were investigated with pyridine adsorption using infrared spectroscopic techniques. It was concluded that when the catalysts composition of the active component V2O5 increased, the supporting material gamma-Al2O3 was covered by a monolayer of V2O5. When the amount of active component was over 11.8 wt.%, the supporting material was covered as multilayer. It was also concluded that after pyridine adsorption, the number of Lewis acid sites of V2O5/gamma-Al2O3 catalyst decreased with increasing V2O5 content. The number of the Bronsted acid sites of the V2O5/gamma-Al2O3 catalyst showed an increase with increasing V2O5 content and reached a maximum for the catalyst with 11.8 wt.% V2O5. Upon further increase of V2O5 content, the number of the Bronsted acid sites decreased.