Premium
Study of the Behavior of an EC Mechanism Using Cyclic and Derivative Chronopotentiometric Techniques with Spherical Electrodes
Author(s) -
LópezTenés Manuela,
Molina Juana María,
Molina Ángela
Publication year - 2004
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200302900
Subject(s) - sphericity , electrode , derivative (finance) , kinetic energy , reciprocal , radius , reaction rate constant , chemistry , thermodynamics , analytical chemistry (journal) , materials science , kinetics , physics , classical mechanics , chromatography , computer science , linguistics , philosophy , computer security , financial economics , economics , composite material
The theory for an EC mechanism in chronopotentiometric techniques – reversal chronopotentiometry, cyclic chronopotentiometry and reciprocal derivative chronopotentiometry – is developed. The equations of this article are valid for spherical electrodes of any size and present a compact and easy‐to‐manage form. Methods for determining kinetic parameters of the chemical reaction are proposed and the influence of the electrode radius is discussed. We conclude that large errors in the determination of these parameters are committed if electrode sphericity is neglected. Reciprocal derivative chronopotentiometry has been applied in its traditional form (d t /d E vs. E ), and in a more recently proposed modality consisting of plotting d t 1/2 /d E vs. E. These techniques are very convenient for studying an EC mechanism since the response is obtained in the form of peaks which are quantitatively related to the kinetic parameters of the chemical reaction. A comparison of the chronopotentiometric methods analyzed leads us to conclude that working curves based on the d t 1/2 /d E vs. E curves are more suitable to obtain accurate values of the rate constants of the chemical reaction.