Theory and highly accurate computation of nonlimiting chronoamperometric currents for theErevCirrreaction mechanism at cylindrical wire electrodes

Abstract

• Theory of single potential step chronoamperometry for the E rev C irr mechanism. • Applicable to infinite cylindrical electrodes, assuming D O = D R . • Highly accurate and efficient C++ procedures for computing the currents. • Useful for validation of simulation methods and experimental data analysis. Theory of single potential step chronoamperometry for the E rev C irr reaction mechanism involving a reversible charge transfer and a (pseudo-) first order irreversible homogeneous follow-up chemical reaction at a cylindrical wire electrode has not been thus far considered in the literature, except for very fragmentary results. Such a theory is presented, and it is shown that the chronoamperometric nonlimiting Faradaic current can be described in terms of a trivariate special function termed icylw EC · . Numerical procedures are elaborated and implemented in C++, that allow one to efficiently compute this function, and the current, with the modulus of the relative error not exceeding about 3 × 10 - 11 (but often smaller, at the level of 10 - 19 - 10 - 15 ). The code for the procedures is freely available. With the help of this code the effects of the electrode curvature and of the homogeneous reaction rate constant, on the current, are briefly investigated and discussed.