Extraction of electrode kinetic parameters from microdisc voltammetric data measured under transport conditions intermediate between steady-state convergent and transient linear diffusion as typically applies to room temperature ionic liquids
Journal
Journal of Physical Chemistry B
Journal Volume
112
Journal Issue
25
Start Page
7560
End Page
7565
ISSN
15206106
Date Issued
2008
Author(s)
Barnes, Alexander S.
Rogers, Emma I.
Streeter, Ian
Hardacre, Christopher
Compton, Richard G.
Abstract
The extraction of electrode kinetic parameters for electrochemical couples in room-temperature ionic liquids (RTILs) is currently an area of considerable interest. Electrochemists typically measure electrode kinetics in the limits of either transient planar or steady-state convergent diffusion for which the voltammetic response is well understood. In this paper we develop a general method allowing the extraction of this kinetic data in the region where the diffusion is intermediate between the planar and convergent limits, such as is often encountered in RTILs using microelectrode voltammetry. A general working surface is derived, allowing the inference of Butler-Volmer standard electrochemical rate constants for the peak-to-peak potential separation in a cyclic voltammogram as a function of voltage scan rate. The method is applied to the case of the ferrocene/ ferrocenium couple in [C2mim][N(Tf) 2] and [C4mim][N(Tf)2]. © 2008 American Chemical Society.
Publisher
American Chemical Society
Type
journal article