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

Abstract

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 gamma-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/gamma-Al2O3. Most catalytic activity was observed when gamma-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 gamma-Al2O3 up to 10 wt%, which led to the highest yield of isophthalonitrile (IPN).