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 V 2 O 5 on various oxides. Catalysts were prepared by wet impregnation method. At first, the loading of V 2 O 5 was varied from 5 wt% to 20 wt% on γ -Al 2 O 3 support to estimate the most effective amount of V 2 O 5 . Second, the effect of catalyst supports was examined at 10 wt% loading of V 2 O 5 . V 2 O 5 /TiO 2 and V 2 O 5 /SiO 2 catalysts were employed to compare the ammoxidation reaction with V 2 O 5 / γ -Al 2 O 3 . Most catalytic activity was observed when γ -Al 2 O 3 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 V 2 O 5 was favorably dispersed on the surface of γ -Al 2 O 3 up to 10 wt%, which led to the highest yield of isophthalonitrile (IPN).