Hydrogenation and oxidation reactions can be carried out in very mild conditions using a three-phase catalytic reactor. The challenge is to overcome the diffusion resistance that affects this type of reactor. The catalytic membrane reactor (CMR), where the membrane is used not only as physical selective barrier but also as a chemical reactor, can be an efficient alternative to more conventional systems in improving the contact among solid catalyst, gas and liquid. The performances of different catalytic membranes were explored in the hydrogenation-isomerisation of methylenecyclohexane, in a temperature range between 288 and 343 K. Comparisons between a classic batch stirred tank and CMR were also carried out. Various characteristics of the reacting system, such as the overall process rate. the effect of temperature, the reaction order with reference to the substrate and the hydrogen and reaction selectivity were studied. (C) 2003 Elsevier B.V. All rights reserved.