A miniaturised hydrogen generator is being developed for small mobile/onboard fuel cell applications based on the concept of partial oxidation of methane (POM). The generator comprises several hundred micro-reactors each in the shape of a tubular vessel fitted with a multi-holed baffle-plate for mixing enhancement. Experiments were conducted on 1: 1 scale replicas of the reactor over a range of temperatures between 300 and 1000 degrees C under both catalytic and non-catalytic conditions. Results indicate that the application of the multiholed baffle-plate considerably improves the conversion rates of reactants and the selectivity of desired products (i.e. H-2) especially when rhodium is used as a catalyst. To the contrary, increasing pressure led to the formation of undesirable soot residues, a reduction in methane conversion and a deterioration of the hydrogen selectivity. (c) 2006 Elsevier Ltd. All rights reserved.