Original scientific paper
https://doi.org/10.5599/jese.2467
Electrochemical impedance spectroscopy measurements on time-variant systems: the case of the Volmer-Heyrovský corrosion reaction. Part I: theoretical description
Nicolas Murer
Jean-Paul Diard
Bogdan Petrescu
Abstract
One of the theoretical requirements of electrochemical impedance spectroscopy measure-ments is that the studied system should not vary with time. Unfortunately, this is rarely the case of physical systems. In the literature, quite a few methods exist to check and correct a posteriori the effect of time-variance, allowing the use of conventional equivalent circuit models to fit and interpret the data. We suggest a different approach where, for a given electrochemical mechanism and specific experimental conditions, assuming stationarity during each measurement, a time- and frequency-dependent expression of the Faradaic impe¬dance is derived from the kinetic equations. The case of a potential relaxation at zero current following an anodic steady-state polarization is considered for a system where a Volmer-Heyrovský corrosion mechanism is supposed to take place.
Keywords
EIS; adsorption; non-stationarity; Faradaic; relaxation; potential decay
Hrčak ID:
328862
URI
Publication date:
20.9.2024.
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