Journal
ANALYTICAL CHEMISTRY
Volume 88, Issue 9, Pages 4724-4732Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.analchem.5b04820
Keywords
-
Categories
Funding
- King Abdullah University of Science and Technology (KAUST) [KUK-C1-013-04]
- Australian Research Council
Ask authors/readers for more resources
Estimation of thermodynamic and kinetic parameters in electrochemical studies is usually undertaken via comparison of the experimental results with theory based on a model that mimics the experiment. The present study examines the credibility of transient d.c. and a.c. voltammetric theory experiment comparisons for recovery of the parameters needed to model the ubiquitous mechanism when an electron transfer (E) reaction is followed by a chemical (C) step in the EC process (A +/- e-reversible arrow(B0,k0,alpha) B reversible arrow (kf)(kb) C). The data analysis has been undertaken using optimization methods facilitated in some cases by grid computing. These techniques have been applied to the simulated (5% noise added) and experimental (reduction of trans-stilbene) voltammograms to assess the capabilities of parameter recovery of E-0 (reversible potential for the E step), k(0) (heterogeneous electron transfer rate constant at E-0), alpha (charge transfer coefficient for the E step), and k(f) and k(b) (forward and backward rate constants for the C step) under different kinetic regimes. The advantages provided by the use of a.c. instead of d.c. voltammetry and data optimization methods over heuristic approaches to experiment-theory comparisons are discussed, as are the limitations in the efficient recovery of a unique set of parameters for the EC mechanism. In the particular experimental case examined herein, results for the protonation of the electrochemically generated stilbene dianion demonstrate that, notwithstanding significant advances in experiment and theory of voltammetric analysis, reliable recovery of the parameters for the EC mechanism with a fast chemical process remains a stiff problem.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available