Ammoxidation of Toluene by Oxygen in Catalyst

Abstract

Ammoxidation of toluene to benzonitrile was studied by pulse reaction method. Ammonia adsorbed on a 10% V205-TiO2 catalyst was quickly oxidized to nitrogen and water at 375°C. At the same time V205 in the catalyst was apparently reduced to V204.33 (Fig.1).Adsorbed toluene was also oxidized by the oxygen in catalyst to toluene dimer, benzaldehyde, ben-laic acid, carbon dioxide and benzonitrile precursor, which was converted to benzonitrile by ammonia, pulse. (Fig.2, 3, 4)Stability of the precursor was examined at 350, 375 and 400°C. Adsorption and oxidation of benzonitrile was negligible in this experiments. The difference of selectivity for benzonitrile formation between continuous flow system and pulse reaction one was discussed.