Steam and auto-thermal reforming of propane over a Ni-Ru/GDC catalyst prepared by hydrothermal method were investigated under intermediate temperature solid oxide fuel cell (IT-SOFC) operating conditions. Such an approach is propaedeutical for the application of the catalyst in IT-SOFC. At reaction temperature higher than 700 degrees C, under both steam reforming (SR) and auto-thermal reforming (ATR), high propane conversion and syngas (H-2 + CO) productivity were obtained. In SR significant amount of filamentous carbon was formed mainly at 600 degrees C, with subsequent catalyst deactivation. In ATR, coke formation was completely depressed and the catalyst resulted to be very stable in all investigated reaction conditions. Notwithstanding the oxygen storage capability and redox properties of ceria in promoting both oxygen activation and carbon residues gasification, without oxygen in gas phase the concentration of oxygen vacancies itself were not able to inhibit carbon deposition. On the other hand, the presence of oxygen in the reaction stream slightly negatively reflects on syngas production, since it promotes CO2 and H2O formation; however, the loss in selectivity is widely compensated by the absence of deactivation phenomena. (c) 2007 Elsevier B.V. All rights reserved.