Heterogeneous catalysts for the dehydrogenation of saturated hydrocarbons

A series of new heterogeneous iridium containing catalysts was synthesized by the incipient wetness method. The used support materials were SiO2, Al2O3, TiO2, ZrO2, and MCM-41. These catalysts are able to dehydrogenate cyclooctane to give cyclooctene and hydrogen without a sacrificing olefin. The catalysts showed TONs up to 1008 in 5 h and selectivities over 90%. The activities, selectivities and stabilities of the catalysts can be increased by addition of suitable support materials and additives. The heterogeneous dehydrogenation reactions showed a high temperature dependence with a temperature maximum depending on the individual coordination compound. The iridium containing catalysts also activated the linear alkanes n-pentane and n-octane in catalytic CH-activation reactions. (c) 2008 Elsevier B.V. All rights reserved.