PdO/NiO/SDC composites (SDC: Sm2O3-doped CeO2) have been proposed to be excellent anodes for single-chamber, intermediate-temperature solid oxide fuel cells (SC-IT-SOFCs) operated under mixtures of CH4 and air, reaching high power densities at relatively low working temperatures. In this work we evaluated the catalytic activity of these composites in the partial oxidation of CH4, finding that their high performance is due to the excellent catalytic properties of these materials. The effect of the addition of PdO was investigated by analyzing NiO/SDC and PdO/NiO/SDC composites under different reaction temperatures and CH4:O-2 ratios. Finally, PdO/NiO/SDC composites were evaluated under operation in SC-IT-SOFCs similar to those reported in the literature using SDC electrolytes and Sm0.5Sr0.5CoO3 cathodes. Our results confirmed the feasibility of SC-IT-SOFCs. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3061170] All rights reserved.