A DFT modeling of the transition state of oxidative dehydrogenation of ethylbenzene over zirconium vanadate catalyst has been carried out. Computations confirm a Mars-Van-Krevelen type redox mechanism in which the catalyst abstracts a hydrogen atom from the hydrocarbon and catalyst is reduced. The reduced catalyst is reoxidized by oxygen from air. Computations suggest the formation of a hydroxyl species over the catalyst surface believed to have been formed due to abstraction of hydrogen atoms from ethyl benzene. A cyclic intermediate is formed which easily accepts one oxygen atom from air to regenerate the catalyst. The study shows that active species is vanadium and it follow a redox order of V=+5, V=+4, V=+3, V=+5.
