The present paper investigates the development of Ir-based catalysts supported on tungstated aluminas for the ring opening reaction of naphthenic molecules using methylcyclohexane (MCH) as a model compound. A series of tungstated aluminas WOx/Al2O3 containing up to 6.0 at.W/nm(2) was prepared. Ir-based catalysts containing 1.2 wt% were obtained by impregnation of these solids. The performance of Ir/WO3/Al2O3 catalysts for methyl cyclohexane ring opening was found to be similar to that observed over the corresponding zirconia-based system indicating that the metal-acid balance (and not the nature of the support) is the key parameter for optimum performance. (C) 2010 Elsevier B.V. All rights reserved.