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Exact solutions of potentiostatic current transients for a corrosion reaction under mixed charge transfer and diffusion control

Journal Article


Abstract


  • An analytical solution has been obtained for the current response transients to a potentiostatic step for a corrosion reaction where a planar metal electrode is immersed in an acidic electrolyte. This solution can be used to provide values of important kinetic parameters of the reaction such as corrosion current and Tafel slopes. The model is derived for conditions of mixed charge transfer and diffusion control and includes the metal ion deposition partial reaction. A Nernstian diffusion model is used, where anodic and cathodic species diffuse in a finite diffusive layer. A numerical solution has previously been published [1], but it is believed that this is the flint time an analytical solution has been presented. Transients obtained by including both the metal dissolution and metal-ion deposition (back) reactions, are compared to those obtained by neglecting the metalion deposition reaction. It is shown that neglecting the back reaction can cause significant errors especially when large cathodic potential steps are applied and as the corrosion current approaches the limiting current density of the cathodic reaction.

UOW Authors


  •   Broadbridge, Philip (external author)

Publication Date


  • 1999

Citation


  • El-Feki, A. A., Broadbridge, P., & Walter, G. W. (1999). Exact solutions of potentiostatic current transients for a corrosion reaction under mixed charge transfer and diffusion control. Mathematical and Computer Modelling, 29(3), 27-41. doi:10.1016/S0895-7177(99)00028-X

Scopus Eid


  • 2-s2.0-0033083363

Web Of Science Accession Number


Start Page


  • 27

End Page


  • 41

Volume


  • 29

Issue


  • 3

Place Of Publication


Abstract


  • An analytical solution has been obtained for the current response transients to a potentiostatic step for a corrosion reaction where a planar metal electrode is immersed in an acidic electrolyte. This solution can be used to provide values of important kinetic parameters of the reaction such as corrosion current and Tafel slopes. The model is derived for conditions of mixed charge transfer and diffusion control and includes the metal ion deposition partial reaction. A Nernstian diffusion model is used, where anodic and cathodic species diffuse in a finite diffusive layer. A numerical solution has previously been published [1], but it is believed that this is the flint time an analytical solution has been presented. Transients obtained by including both the metal dissolution and metal-ion deposition (back) reactions, are compared to those obtained by neglecting the metalion deposition reaction. It is shown that neglecting the back reaction can cause significant errors especially when large cathodic potential steps are applied and as the corrosion current approaches the limiting current density of the cathodic reaction.

UOW Authors


  •   Broadbridge, Philip (external author)

Publication Date


  • 1999

Citation


  • El-Feki, A. A., Broadbridge, P., & Walter, G. W. (1999). Exact solutions of potentiostatic current transients for a corrosion reaction under mixed charge transfer and diffusion control. Mathematical and Computer Modelling, 29(3), 27-41. doi:10.1016/S0895-7177(99)00028-X

Scopus Eid


  • 2-s2.0-0033083363

Web Of Science Accession Number


Start Page


  • 27

End Page


  • 41

Volume


  • 29

Issue


  • 3

Place Of Publication