HIGH-PERFORMANCE CATALYZED-REACTION LAYER FOR MEDIUM-TEMPERATURE OPERATING SOLID OXIDE FUEL-CELLS

New concepts for a high performance catalyzed-reaction layer for mediu m temperature operating solid oxide fuel cells were proposed. Mixed co nducting oxide particles, samaria-doped ceria (SDC), were employed as the anode material utilizing highly dispersed noble metal catalysts on their surface. As the cathode material, Sr-doped LaMnO3 (LSM) particl es catalyzed with microcrystalline Pt were employed. Performances of t he anode or cathode were examined in the cell using yttria-stabilized zirconia electrolyte at a series of operating temperatures. It was fou nd that the anodic polarization resistance and its activation energy w ere greatly decreased by loading only a small amount of the catalysts (such as Ru, Rh, and Pt) onto the SDC particles. The polarization loss at the anode showed a minimum value by using the SDC particles with a mean diameter of 1.5 to 2/0 mum. A large depolarizing effect was also observed with a Pt-catalyzed LSM cathode, especially at high current densities.