Quantum chemistry and molecular dynamics were used to evaluate the performance of solid oxide fuel cell anode materials in the presence of H2 and H2 S. The most common anode material Ni-yttria-stabilized zirconia (Ni-YSZ) was used for the study. It was found that the presence of H2 S has an important effect on the oxidation of H2. Thermodynamics and transport limitations favor the oxidation of H2 instead of H2 S. Furthermore it is predicted that the presence of H2 S slows down the oxidation of the hydrogen due to transport limitations (the H2 S molecules tend to be surrounded by H2 molecules in the media). © 2006 The Electrochemical Society. All rights reserved.