Presented is a study of hydrogen-rich gas generation by selective catalytic oxidation of gasoline in a nearly adiabatic monolith reactor. Experiments were conducted using a gasoline mixture containing 191 hydrocarbon species, while corresponding thermodynamic models employed a surrogate mixture of 29 organics with well-defined properties. Based on the data obtained, it was demonstrated that a nearly equilibrium synthesis gas could be produced using catalytic monoliths. Also discussed are problems encountered with a short contact time reactor operating at a pilot-scale, issues that are largely independent of the catalysts employed. It was found that this particular reactor design is prone to pre-reformation of the fuel prior to catalytic reaction. In addition, the breakthrough of the feed mixture was found to arise near the reactor wall under certain circumstances. Feed composition, superficial velocity, and various reactor design factors were all found to affect these phenomena. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.