Procedures for computer simulation of kinetics of electrochemical surface processes

Abstract

Abstract The kinetics of surface processes are of current interest in electrochemical surface science. Rates of electrode processes depend both exponentially on electrode potential, and linearly and exponentially on terms involving coverage θ by electrodeposited species in the reaction. The rates are also proportional to the time-derivative of the coverage θ. Several consecutive reaction steps can also be involved in a given overall surface process. This situation generates a system of simultaneous non-linear, first-order differential equations that rarely have analytical solutions. Computer simulation of the complex kinetic behavior which arises for such surface reaction schemes can, however, be made by numerical solution of the differential equations by iterative integration procedures. Procedures are described for these simulations and for simulations of the diagnostic operations that are performed in actual experiments using the linear voltage-sweep method or “cyclic voltammetry”. Characteristic general features of the kinetics of various schemes of surface reactions can be derived from the simulation calculations which enable various types of reactions to be recognized from the experimental behavior observed in linear voltage-sweep experiments.