INVESTIGATION OF ACTIVE CARBON FOR FUEL-CELL ELECTRODES

The influence of grain size, mode of catalyst impregnation, and different surface treatments on the electrochemical activity of active carbon for hydrogen fuel-cell electrodes was studied. The experiments were done in a special powder-electrode assembly without any binding material, in 5 N H2SO4 and 6 N KOH at 40°C. The best results were obtained with 60-100 μm particles, washed with azeotropic HCl, heated at 950°C in CO2 and impregnated with 2 mg Pt per cm2 of the electrode. The polarization curves, after correction for ohmic drop, had slopes less than 1Ω cm2. The effects obtained by the treatment are explained by the change of the state of the carbon surface. © 1969.