A comparison of simulated and experimental voltammograms obtained for the [Fe(CN)(6)](3-/4-) couple in the absence of added supporting electrolyte ata rotating disk electrode

The voltammetric behavior of the [Fe(CN)(6)](3-/4-) couple at a glassy carb on rotating macrodisk electrode without added supporting electrolyte is sho wn to be in close to ideal agreement with the theory presented over a wide range of electrode rotation and scan rates when the concentration of electr oactive species used is 50 mM. The influences of migration, uncompensated r esistance, heterogeneous charge-transfer kinetics, and inhomogeneous diffus ion are shown to be well modeled by a finite difference simulation scheme t hat affords excellent agreement between experiment and theory. The use of t he rotating disk electrode, even when only moderate rotation rates are empl oyed, is shown to eliminate the problem with natural convection that exists when using stationary electrodes (macro- or microdisk) and that is enhance d in the absence of added supporting electrolyte. Consequently, it has been concluded that the rotating disk electrode method represents an almost ide al technique for conducting studies without added supporting electrolyte.