CYCLIC AND LINEAR SWEEP VOLTAMMETRY AT TUBULAR ELECTRODES .5. KINETIC PROCESSES

The theory of cyclic voltammetry, in hydrodynamic systems, is extended to EC processes in which the reversible charge transfer is followed by a first order, homogeneous, irreversible chemical reaction. Laplace transformation and its properties have been used to convert the system of convective-diffusion equations, representing the boundary value problem, to an integral equation which is solved numerically. With slight modification the theory has been applied to linear sweep voltammetry for which theoretical current-potential curves have been obtained and the effects of reaction rate constant, velocity and potential scan rate on the shape of curve are shown graphically. A simple procedure for the determination of the reaction rate constant is presented. Theoretically derived results have been verified experimentally by carrying out the oxidation of N,N'-dimethyl-p-phenylenediamine in the presence of OH- ions at the tubular platinum electrode.