In this work, quantum chemical methods were applied to study light alkane hydrogen-exchange reactions on a zeolite cluster, RH+H3SiOAlH2(OH')SiH3-> RH'+H3Si(OH)AlH2OSiH3. Methane, ethane, propane, and butane reactions were investigated. The reactants, products, and transition state structures were optimized using the B3LYP density functional theory method and the final energies were calculated using CBS-QB3, a complete basis set composite energy method. The computed activation barriers ranged from 28.32 kcal/mol for secondary hydrogen exchange of butane to 33.53 kcal/mol for methane. The relationship between activation energy and deprotonation energy was also investigated and a linear correlation was proposed in this work. (c) 2005 Elsevier B.V. All rights reserved.