On the relationship between limiting current and mass-transport impedance at zero frequency

Abstract

The zero-frequency reversible mass transport impedance (measured at the reversible potential) is shown to be simply related to the limiting current density (far from the reversible potential). For mass transport of a single species exchanging n electrons with the electrode, their product is RT/nF . For the two-species case, O + ne -> R, the same product is found, provided the harmonic mean of the anodic and cathodiclimiting currents is used. This applies for most of the mass-transport situations found in electrochemistry, including with forced convection or for electrodes without uniform accessibility.