Effect of uncompensated ohmic drop in surface linear potential sweep voltammetry: Application to the determination of surface rate constants

Abstract

The effect of ohmic drop on linear potential sweep voltammograms is studied theoretically in the case of quasi-reversible surface redox reactions. The uncompensated resistance produces manifestations on reversible peaks (shape, shift of peak potential) which are very similar to those due to a slowness of the electrochemical reaction, so that it is practically impossible to distinguish them on the basis of the experimental data alone. The limitations of the method for the determination of rate constants of surface electrochemical processes are discussed. A comparison is made with the faradaic impedance method.