# A Simple Method to Establish the Relationship Between the Equilibrium Polarization Resistance and the Elementary Kinetic Parameters of an Electrocatalysed Reaction

Authors
• 1 Instituto de Química Aplicada del Litoral, IQAL (UNL-CONICET), Programa de Electroquímica Aplicada e Ingeniería Electroquímica, PRELINE (FIQ-UNL), Santiago del Estero 2829, Santa Fe, Argentina , Santa Fe (Argentina)
Type
Published Article
Journal
Electrocatalysis
Publisher
Springer US
Publication Date
Dec 06, 2017
Volume
9
Issue
3
Pages
409–415
Identifiers
DOI: 10.1007/s12678-017-0443-1
Source
Springer Nature
Keywords
A simple and rigorous methodology to establish the relationship between the faradaic equilibrium polarization resistance of an electrocatalytic reaction with the elementary kinetic parameters involved in the reaction mechanism is proposed. It was derived through an alternative method, which avoided the differentiation of the corresponding current-overpotential dependence. This formalism includes the cases where both, reactants and products, exhibit diffusion contributions. It is demonstrated that the equilibrium polarization resistance is the sum of both, faradaic and diffusion, contributions. Each diffusion term has a linear variation with the inverse of the limiting diffusion current density of the species involved. This behavior was exemplified with two different experimental data sets for the hydrogen electrode reaction, obtained on a rotating disc and microelectrodes, respectively. Graphical AbstractExperimental equilibrium polarization resistance is the sum of faradaic (Rpo\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${R}_p^o$$\end{document}) and diffusion (Rpd\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${R}_p^d$$\end{document}) contributions. A simple and novel methodology is presented for the derivation of the relationship between Rpo\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${R}_p^o$$\end{document} and the equilibrium reaction rates of the elementary steps (vie\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${v}_i^e$$\end{document}). It is also demonstrated the linear variation of Rpd\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${R}_p^d$$\end{document} with the inverse of the limiting diffusion current density.