Chronoamperometry homogeneous chemical reaction

The behavior of it1/2 as a function of time can be influenced substantially by the presence of chemical reactions that are coupled to the electrode process (see Chap. 2). Consequently, characteristic variations of it1/2 versus t have been effectively utilized for the quantitative study of such homogeneous chemical reactions. The ECE reaction in which a chemical step exists between two electron transfer steps is one mechanism that has been investigated by means of chronoamperometry ... 

Kong et al. [90] applied the electrochemical approach to the study of a two-phase azo coupling facilitated by reverse PTC. Cyclic voltammetry and chronoamperometry were employed to evaluate quantitatively the rate constants for the reaction. The process was interpreted in terms of an EC mechanism, i.e., diffusion-controlled electrochemical charge transfer followed by a homogeneous chemical reaction. The authors highlighted the usefulness of this approach based on the factors that enable the estimation of the contributions of the chemical reaction, mass transfer, partitioning, and the adsorption of reactants at the interface to the overall two-phase reaction. 

Chronoamperometry Chronoamperometry involves the study of the variation of the current response with time under potentiostatic control. Generally the working electrode is stepped from a potential at which there is no electrode reaction to one corresponding to the mass-transport-limited current, and the resulting current-time transient is recorded. In double-step chronoamperometry, a second step inverts the electrode reaction and this method is useful in analysing cases where the product of the initial electrode reaction is consumed in solution by a coupled homogeneous chemical reaction. 

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