The conversion of the C3 organics propane, propene, isopropanol and acetone in auto-thermal and endothermic steam reforming conditions has been investigated over a Pd-Cu/Al2O3 catalyst in a flow reactor. Although several reactions may occur at lower temperatures (like dehydrogenation, oxidative dehydrogenation, dehydration and combustion), steam reforming of 2-propanol, acetone and propane only start above 850 K and with incomplete selectivity. Cracking and methanation lower the selectivity to Co-x and hydrogen. The C-C bond breaking step is considered to be rate determining. The presence of an oxygenated functional group is consequently not useful to lower reaction temperature, although the use of the alcohol and the ketone may be interesting because of the renewable nature of these reactants. Steam reforming of propene starts at significantly lower temperature (600-700 K) and is by far the most selective to Co-x and hydrogen over our catalyst. (c) 2005 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.