Characterization and catalytic properties of vanadia/titania xerogel catalysts for ammoxidation of m-xylene

Vanadia/titania composite xerogel catalysts prepared by the alkoxide and non-alkoxide sol-gel process were evaluated as catalysts in a fixed-bed reactor for the gas phase ammoxidation of w-xylene in a temperature range from 573 to 698 K. The effects that the reaction temperature and the vanadia loadings had on had the reaction characteristics were investigated. A maximum yield of 72 % of isophthalonitrile (IPN) was obtained using a vanadia loading of 3 wt% at 648 K with a contact time of 0.5 s. The vanadia/titania xerogel catalysts were characterized through nitrogen adsorption-desorption, temperature-programmed reduction (TPR), X-ray diffraction (XRD), and scanning electronic microscopy (SEM) analyses to explain their excellent catalytic performance in comparison with those of conventionally impregnated catalysts.