Many readily available fuels, to some extent, contain sulfur, which is very detrimental to existing solid oxide fuel cells (SOFCs). A pyrochlore-based anode material, Gd2Ti1.4Mo0.6O7, showed remarkable tolerance to sulfur-containing fuels. The anode/electrolyte interfacial resistance was only 0.2 Omega cm(2) at 950 degrees C in a fuel gas mixture of 10% H2S and 90% H-2, demonstrating a peak power density of 342 mW cm(-2). The fuel cell operated under these conditions continuously for 6 days without any observable degradation, suggesting that Gd2Ti1.4Mo0.6O7 anode exhibits not only excellent stability but also good catalytic activity toward the oxidation of hydrogen sulfide. (c) 2005 The Electrochemical Society.