Catalytic activity and characterization of V₂O₅/γ-Al₂O₃ for ammoxidation of m-xylene system

An ammoxidation of m-xylene was evaluated in a fixed-bed reactor using V₂O₅ on various oxides. Catalysts were prepared by wet impregnation method. At first, the loading of V₂O₅ was varied from 5 wt% to 20 wt% on γ-Al₂O₃ support to estimate the most effective amount of V₂O₅. Second, the effect of catalyst supports was examined at 10 wt% loading of V₂O₅. V₂O₅/TiO₂ and V₂O₅/SiO₂ catalysts were employed to compare the ammoxidation reaction with V₂O₅/γ-Al₂O₃. Most catalytic activity was observed when γ-Al₂O₃ was used as a support. Careful characterization was followed by physicochemical techniques, such as BET measurement, X-ray diffraction (XRD), Raman spectroscopy and temperature-programmed reduction (TPR). The results provided the clue that monolayer V₂O₅ was favorably dispersed on the surface of γ-Al₂O₃ up to 10 wt%, which led to the highest yield of isophthalonitrile (IPN).