Theory and highly accurate computation of nonlimiting chronoamperometric currents for the ErevCirr reaction mechanism at cylindrical wire electrodes

Theory of single potential step chronoamperometry for the ErevCirr 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 icylwEC (center dot). 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 x 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.

Automated summary

The theory of single potential step chronoamperometry for the ErevCirr reaction mechanism involving reversible charge transfer and an (pseudo-) first order irreversible homogeneous follow-up chemical reactions at a cylindrical wire electrode has not been previously considered in literature, except for fragmentary results. A new theory is presented in this paper, with numerical procedures elaborated and implemented in C++ to efficiently compute a special trivariate function to describe nonlimiting Faradaic current. The effects of electrode curvature and homogeneous reaction rate constant on the current are briefly investigated and discussed using the freely available code for the procedures.