Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations: Part 11. Patch-adaptive simulation of example transient experiments described by kinetic models involving simultaneously distributed and localised unknowns, in one-dimensional space geometry

Abstract

The patch-adaptive strategy for electrochemical kinetic simulations, with extensions described in Part 10, is applied to three representative examples of time-dependent kinetic models in one-dimensional space geometry, characterised by the simultaneous presence of spatially distributed and localised unknowns. The models describe: potential step chronoamperometry for a diffusion-controlled charge transfer reaction accompanied by the adsorption of reactants at the electrode; cyclic voltammetry for an electrochemical deposition–precipitation mechanism; and double potential step chronoamperometry for an oscillatory system involving a diffusion-controlled charge transfer reaction having a negative polarisation resistance, in the presence of double layer charging, and ohmic potential drops. The strategy provides accurate, efficient and nearly automatic solutions for these examples, which confirms the overall adequacy of the extensions of the strategy, associated with the handling of localised unknowns. In the third example, the adaptive simulations are very detailed and informative. They confirm the occurrence of numerical artefacts in the literature results of fixed grid simulations for this example.