Oxidative steam reforming of propane was tested over four Pt-Ni/delta-Al(2)O(3) bimetallic catalysts aiming to investigate the effect of metal loadings and Ni:Pt loading ratio on catalyst performance. A trimetallic Pt-Ni-Au/delta-Al(2)O(3) catalyst was additionally studied aiming to understand the effect of Au presence. Reaction temperature, carbon to oxygen ratio, and residence time were taken as the reaction parameters. The effect of C/O(2) ratio on the hydrogen production and H(2)/CO selectivity was found dependent on the Pt and Ni loadings. The results underlined the importance of C/O(2) ratio as air optimization parameter for product distribution. The highest hydrogen production and H(2)/CO ratio levels were obtained for the highest C/O(2) ratio tested. An optimum Ni:Pt weight ratio was found around 50 due to suppressed methanation and enhanced hydrogen production activities of these catalysts. The presence of gold in the trimetallic catalyst caused poor activity and selectivity in comparison to bimetallic catalysts. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved