Re-examination of the diffusion–convection impedance for a uniformly accessible rotating disk. Computation and accuracy

• Symbolic/numerical approach of 1-D diffusion–convection near RDE using Mathematica.
• Highly accurate computation of the 1-D diffusion–convection impedance for RDE.
• Checking the validity/accuracy of previous derivations in the literature.

The first aim of this work is to get highly accurate values of the diffusion–convection impedance for dissolved species reacting at the surface of a uniformly accessible rotating disk electrode (RDE). Three computation strategies are examined and compared for this purpose. Each procedure requires, first, a solution (series solution or numerical solution) of von Kármán approximation of the Navier–Stokes equations for evaluation of the components of fluid velocity induced by electrode rotation, and, next, a numerical solution of the one-dimensional diffusion–convection equation for RDE under harmonic conditions. The fully numerical method presented in this article provides benchmark data, which can be used to check the validity of previous derivations of the diffusion–convection impedance in the literature, as well as the accuracy of computation methods based on series expansions. Additional information upon the diffusion–convection impedance pertaining to RDE is reported in the supplementary material associated with this article.