ELECTROREDUCTION OF OXYGEN IN POLYMER ELECTROLYTE FUEL-CELLS BY ACTIVATED CARBON-COATED COBALT NANOCRYSTALLITES PRODUCED BY ELECTRIC-ARC DISCHARGE

Carbon-coated fee cobalt nanocrystallites produced by the carbon are m ethod have practically no activity as catalysts for O-2 reduction in H -2/O-2 polymer electrolyte fuel cells. This material, containing 17.0 wt % Co, was activated by a pyrolysis step at 1000 degrees C in Ar con taining acetonitrile vapor. When it was used at the cathode of a singl e fuel cell element, it provided an initial current of 0.10 A/cm(2) mg of Co at 0.5 V and 50 degrees C. This current decreased by 40% after 300 h. Only a fraction of the carbon-coated metal in the initial mater ial was activated by the pyrolysis treatment. XPS and TEM characteriza tions were performed on the catalyst at various stages of its preparat ion.