Use of sensitivity analysis methods in the modelling of electrochemical transients - Part 1. Gaining more insight into the behaviour of kinetic models

Sensitivity analysis is a commonly accepted methodology of studying the effect of parameter variations on the behaviour of mathematical models in various branches of chemical kinetics. However, it has not yet found wider application in electrochemical kinetics. In this paper we perform an introductory investigation of the utility of formal methods of sensitivity analysis for the modelling of electrochemical transients. We calculate and analyse first-order parametric sensitivity coefficients for the cyclic voltammetric transient corresponding to a quasi-reversible charge-transfer reaction E-qrev, assuming potential-dependent charge-transfer coefficients, and for the chronopotentiometric transient corresponding to a CrevE reaction mechanism, taken as example problems. We show that this local sensitivity analysis provides straightforward quantitative answers to a number of fundamental questions about the dependencies of the transients on model parameters. Therefore, we recommend that sensitivity analysis be used in conjunction with traditional digital simulations, resulting in an added insight into the behaviour of kinetic models. (C) 1998 Elsevier Science S.A.