Abstract
The reduction of gaseous oxygen on carbon supported platinum electrodes has been studied at 150 degrees C with polarization and potential decay measurements. The electrolyte was either 100 weight percent phosphoric acid or that acid with a fluorinated additive, potassium perfluorohexanesulfonate (C6F13SO3K). The pseudo-Tafel curves of the overpotential vs. log (ii(L)/(i(L) - i)) show a two-slope behavior, probably due to different adsorption mechanisms. The potential relaxations as functions of log (t + tau) and log (-d eta/dt) have been plotted. The variations of these slopes and the dependence of the double-layer capacitance on the overpotential depended on the electrode manufacture and the kind of electrolyte (whether containing the fluorinated additive or not).
Original language | English |
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Journal | Journal of The Electrochemical Society |
Volume | 142 |
Issue number | 10 |
Pages (from-to) | 3250-3256 |
ISSN | 0013-4651 |
DOIs | |
Publication status | Published - 1995 |