Polarographic Method for the Indirect Determination of Polarization Curves for Oxygen Reduction on Various Metals. 1. Description of the Method-Case of Platinum.

摘要

An indirect method for determining polarization curves for the electrolytic reduction of oxygen is described and applied to the case of platinum. The electrode, on which the oxygen reduction is studied, is polarized at a constant potential in a closed vessel containing a solution initially saturated with air. The oxygen concentration is determined by the polarographic method at various time intervals. The current for oxygen reduction is calculated from these data. The complete polarization curve is determined by repeating the experiment for several values of the potential of the electrode. The contributions of the two and four electron reduction processes, i.e., reductions of oxygen to hydrogen peroxide and to water, respectively, are also calculated. Equilibrium conditions for the electrolytic reduction of oxygen are derived from thermodynamic data. jg.