Ammoxidation of Toluene and Alkylbenzenes

Toluene can be readily ammoxidized to benzonitrile, usually over supported vanadium oxide and vanadium phosphate catalysts [e. g. 9,57]. Besides catalyst choice, catalytic performance mainly depends on the reaction conditions. Excess ammonia, as mentioned above, significantly increases nitrile selectivity by blocking sites responsible for consecutive oxidation ammonia also frequently reduces catalyst activity [1]. Water vapor in the reactant stream can also improve selectivity by blocking sites for total oxidation [38] or providing Brdnsted sites for the activation of ammonia [51]. 

The temperature range for the catalytic reaction may reach from 600 K to about 700 K. Increasing temperature normally results in increasing conversion and reduced selectivity and, hence, for every catalyst used the optimum conditions must he carefully determined. Toluene conversion ranges from 50 to 100 % and 

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