STUDIES ON CATALYSIS OF FERROSILICATES FO R OXIDATION-DEHYDROGENATIONOF ETHYLBENZENE - EFFECT OF EXCHANGED CATIONS AND HYDROTHERMAL TREATMENT ON ACTIVITY

The catalytic activity and selectivity of FeZSM-5 catalysts for oxidat ion-dehydrogenation of ethylbenzene(EB) were examined at 823 K and EB : O-2 = 1.0. The influence of exchanged cations, hydrothermal treatmen t and dispersity of Fe2O3 on oxidation-dehydrogenation activity of EB over FeZSM-5 was also studied. XPS, ESR and TPR techniques were used f or the determination of states and properties of iron in FeZSM-5. The results indicate that framework iron and highly dispersed nonframework iron used as Lewis acidic sites and basic sites with suitable strengt h construct the active centers of EB oxidation-dehydrogenation.