LOW-TEMPERATURE POLARIZATION OF PLATINUM-CATALYZED AIR CATHODES IN ALKALINE ELECTROLYTE

Polarization curves have been determined for oxygen reduction on Teflon-bonded platinum black diffusion electrodes in 30% KOH solution in the temperature range of 25 degree to minus 40 degree C. From this data the exchange current densities as a function of temperature and the activation energy at zero overpotential for oxygen reduction on platinum-catalyzed electrodes have been calculated and it was shown that the cathode potential at any current vs. a standard hydrogen electrode increased (became more anodic) with decreasing temperature.