Theoretical study of ethene hydrogenation reaction on Ir4 tetrahedral cluster

Hydrogenation reaction of ethene on free Ir4 cluster was theoretically investigated using DFT B3LYP level of theory with LanL2Dz basis set. It was found that hydrogen molecule adsorption proceeded without an apparent transition state structure and the adsorption energy was predicted to be −93.7 kJ/mol. Two possible channel of hydrogenation reaction were investigated. Distortion of cluster frame and high values of activation energies make these channels unfavorable. It was shown that inclusion of magnesium oxide (MgO) support model in our calculations account for a considerable variation of geometric parameters of Ir4 cluster. The bonding of a single carbon ligand to the supported tetrahedral Ir4 cluster at the on-top site was also modeled to probe changes in geometric parameters in comparison with unsupported cluster. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011