Cu-Co bimetallic mixtures with ceria and YSZ have been investigated as solid oxide fuel cell (SOFC) anodes. While pure Co is unstable in dry CH4 at 1073 K due to severe carbon formation, Cu-Co mixtures with even 90 wt % Co showed only small amounts of carbon following exposure to dry CH4 for 2 h at 1073 K. Cells based on Cu-Co mixtures showed improved performance in both H-2 and CH4 compared to cells prepared with only Cu. Finally, a cell with a 50: 50 ratio of Cu and Co was shown to be stable for 500 h in humidified (3 mol % H2O) CH4 at 1073 K. (C) 2004 The Electrochemical Society.