The catalytic activity of some carbonaceous adsorbents in the oxidative dehydrogenation of ethylhenzene was investigated. By proper selection of conditions, the results of these studies indicate that comparable conversions and selectivities can be attained with these catalysts at significantly lower temperatures than those reported for metal oxide catalysts. The effects of oxygen concentration in the carrier gas, contact time, and the addition of dopants and inhibitors to the reaction have been studied. Changes in these variables produce substantial changes in the conversion and selectivity of the reaction. One of the shortcomings of this reaction is coke formation. Studies with inhibitors suggest the cause of coke formation and methods for inhibiting it.