Surprising dependence of the current density of bromate electroreduction on the microelectrode radius as manifestation of the autocatalytic redox-cycle (EC″) reaction mechanism

Dmitry Konev 1, 2 Anatoly Antipov 1, 2 Mikhail Petrov 1, 2 Maria Shamraeva 2 Mikhail Vorotyntsev 3, 2, 1, 4, *
* Auteur correspondant
1 Mendeleev University of Chemical Technology of Russia
2 MSU - Lomonosov Moscow State University
3 Institute for Problems of Chemical Physics
4 ICMUB - Institut de Chimie Moléculaire de l'Université de Bourgogne [Dijon]
Abstract : Bromate reduction from strongly acidic solutions under steady-state conditions in the presence of a very small amount of bromine has been studied voltammetrically at disk microelectrodes of various radii. In conformity with theoretical predictions the intensity of the average current density depends on the electrode size in a non-monotonous manner, passing through a maximum for a certain radius. This behavior is a direct consequence of the autocatalytic character of this process where the non-electroactive bromate anion is reduced owing to the catalytic cycle based on the bromine/bromide redox-mediator couple. The experimentally observed dependence of the maximal current density, jmax, on the inverse disc radius, 1/r0, for electrodes of larger sizes approaches a straight line corresponding to the “strong current limit”, which exceeds the diffusion-limited current density for bromate ion.
Keywords : Autocatalytic cycle Bromine/bromide redox mediation Comproportionation reaction Disk microelectrode steady-state conditions square-wave voltammetry 2nd-order reactions cation adsorption limiting currents acidic-solution electrode kinetics anion transport
Type de document :
Article dans une revue
Domaine :
Liste complète des métadonnées
https://hal-univ-bourgogne.archives-ouvertes.fr/hal-01856654
Contributeur : Icmub - Université de Bourgogne <>
Soumis le : lundi 13 août 2018 - 11:09:44
Dernière modification le : mercredi 4 septembre 2019 - 17:36:02

Identifiants

Collections

UNIV-BOURGOGNE | CNRS | INC-CNRS | ICMUB

Citation

Dmitry Konev, Anatoly Antipov, Mikhail Petrov, Maria Shamraeva, Mikhail Vorotyntsev. Surprising dependence of the current density of bromate electroreduction on the microelectrode radius as manifestation of the autocatalytic redox-cycle (EC″) reaction mechanism. Electrochemistry Communications, Elsevier, 2018, 86, pp.76 - 79. ⟨10.1016/j.elecom.2017.11.006⟩. ⟨hal-01856654⟩

Exporter

BibTeX TEI DC DCterms EndNote

Partager

Métriques

Consultations de la notice

64

Contact

Informations

CCSD