Jointly published by React.Kinet.Catal.Lett. Akadémiai Kiadó, Budapest Vol. 91, No. 1, 131−139 (2007) and Springer, Dordrecht 10.1007/s11144.007.5072.x 0133.1736/2007/US$ 20.00. © Akadémiai Kiadó, Budapest. All rights reserved. RKCL5072               ! "  #$ ! Chemistry Department, Yarmouk Unversity, P.O.Box 566, Irbid, Jordan         #%&’& Hydrogenation of phenylpropanal over Ir was investigated under mild conditions. An LH.kinetic model is presented that describes successfully experimental results specially the negative effects of temperature and initial concentrations. : Hydrogenation, phenylpropanal, iridium, kinetics  Cinnamyl alcohol (III) is a much valued substance in the fragrance, pharmaceutical and fine chemical industries. Its production via the heterogeneously catalyzed selective reduction of cinnamaldehyde over platinum group metals, although superior over conventional methods in saving resources and reducing waste material, is for thermodynamic and kinetic reasons of limited application. Various approaches have been tested in an attempt to improve the ______________________ * Corresponding author. E.mail: ayman@yu.edu.jo