Effect of diffusion-layer morphology on DMFC performance
The performance of solid-polymer-electrolyte DMFCs is substantially influenced by the morphology of the gas diffusion layer (GDL) in the catalytic electrodes. Cells utilizing GDLs made with high-surface-area Ketjen Black carbon, with optimized thickness, show better performance compared with cells utilizing Vulcan XC-72 carbon or 'acetylene black' carbon in the GDL. Cells with a hydrophilic diffusion layer on the anodes and a hydrophobic diffusion layer on the cathodes yield better performance. M. Neergat and A.K. Shukla: J. of Power Sources 104(2) 289-294 (15 February 2002).
High-performance SOFC anodes for methane/air mixtures at reduced temperatures
Electrocatalytic oxidation of methane over anodes in single-chamber SOFCs, 0-10 wt% Pd-30 wt% Ce 0.8 Sm 0.2 O 1.9 (samaria-doped ceria, SDC)-Ni|SDC|Sm 0.5 Sr 0.5 CoO 3 , was studied in a methane/air mixture between 450 and 550Β°C. Adding a small amount of Pd (0.145 mg/cm 2 ) to the anode significantly promoted partial oxidation of methane by oxygen to form hydrogen and CO, resulting in electromotive forces of ca. 900 mV from the cell and extremely small anode electrode-reaction resistances. Peak power densities, using a 0.15 mm-thick SDC electrolyte, reached 644, 467 and 269 mW/cm 2 at 550, 500 and 450Β°C, respectively.