Concentration overpotential
Posted on 11-03-2010IUPAC Compendium of Chemical Terminology 2nd Edition (1997)
The concentration overpotential of an electrode reaction at a given electrode
current density (c.d.) is basically the difference in equilibrium potentials
across the diffusion layer. More precisely, it is the potential of a
reference electrode (of the same electrode reaction as the working electrode)
with the interfacial concentrations which establish themselves at
c.d., relative to the potential of a similar reference electrode with the
concentrations of the bulk solution. From such a measured potential difference,
with c.d. flowing, one needs to subtract the ohmic potential drop
prevailing between the two electrodes.
1981, 53, 1838