A two-dimensional isothermal model of an SOFC operating with a syngas fuel based on button cell geometry was developed. Momentum, mass and charge transport coupled with electrochemical and chemical reactions were considered. The developed model has been validated by showing good agreement with experimental data for various syngas compositions obtained at an operating temperature of 900 degrees C. However, the model predictions deviate somewhat from the experimental data at 800 degrees C. Visual and SEM investigation of the anode surface after completion of each experiment showed that excessive amounts of carbon form on the anode surface and that the Ni catalyst delaminates from the anode during cell operation at 800 degrees C. In contrast, no carbon formation was observed and only a small amount of Ni delaminated from the anode during operation at 900 degrees C. The model was further applied to predict carbon formation observed experimentally, and to study the impact of operating conditions on carbon formation and determine a suitable range of conditions that suppress its onset. (c) 2006 Elsevier B.V. All rights reserved.