Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions

The 0reduction of O2 at Fe3O4 cathodes in alkaline solutions takes place at electrode potentials where partial reduction of the hydrated Fe(III) surface layer occurs. Simultaneous electroreduction of the surface Fe(III) oxide and dioxygen suggests that octahedrally coordinated surface ferrous ions [...

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Autores principales: Vago, E.R., Calvo, E.J.
Formato: JOUR
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00220728_v339_n1-2_p41_Vago
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00220728_v339_n1-2_p41_Vago2023-10-03T14:25:46Z Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions Vago, E.R. Calvo, E.J. The 0reduction of O2 at Fe3O4 cathodes in alkaline solutions takes place at electrode potentials where partial reduction of the hydrated Fe(III) surface layer occurs. Simultaneous electroreduction of the surface Fe(III) oxide and dioxygen suggests that octahedrally coordinated surface ferrous ions [Fe(II)OH-], are the active sites for oxygen electrocatalysis as proposed earlier for passive iron. The electroreduction of O2 on Fe3O4 cathodes is a two-electron process: O2 + H2O + 2e- → HO2- + HO- Further decomposition of the intermediate peroxide is catalysed by reduced magnetite with a high turnover: 2HO2- → O2 + 2HO- As a consequence of oxygen recycling the apparent number n* of electrons exchanged per oxygen molecule is strongly dependent on mass transport conditions. These results are relevant to understanding the mechanisms of reactions involved in the overall complex corrosion processes of ferrous alloys in aqueous aerated environments and in atmospheric corrosion. © 1992. Fil:Vago, E.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Calvo, E.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00220728_v339_n1-2_p41_Vago
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
description The 0reduction of O2 at Fe3O4 cathodes in alkaline solutions takes place at electrode potentials where partial reduction of the hydrated Fe(III) surface layer occurs. Simultaneous electroreduction of the surface Fe(III) oxide and dioxygen suggests that octahedrally coordinated surface ferrous ions [Fe(II)OH-], are the active sites for oxygen electrocatalysis as proposed earlier for passive iron. The electroreduction of O2 on Fe3O4 cathodes is a two-electron process: O2 + H2O + 2e- → HO2- + HO- Further decomposition of the intermediate peroxide is catalysed by reduced magnetite with a high turnover: 2HO2- → O2 + 2HO- As a consequence of oxygen recycling the apparent number n* of electrons exchanged per oxygen molecule is strongly dependent on mass transport conditions. These results are relevant to understanding the mechanisms of reactions involved in the overall complex corrosion processes of ferrous alloys in aqueous aerated environments and in atmospheric corrosion. © 1992.
format JOUR
author Vago, E.R.
Calvo, E.J.
spellingShingle Vago, E.R.
Calvo, E.J.
Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
author_facet Vago, E.R.
Calvo, E.J.
author_sort Vago, E.R.
title Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
title_short Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
title_full Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
title_fullStr Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
title_full_unstemmed Electrocatalysis of oxygen reduction at Fe3O4 oxide electrodes in alkaline solutions
title_sort electrocatalysis of oxygen reduction at fe3o4 oxide electrodes in alkaline solutions
url http://hdl.handle.net/20.500.12110/paper_00220728_v339_n1-2_p41_Vago
work_keys_str_mv AT vagoer electrocatalysisofoxygenreductionatfe3o4oxideelectrodesinalkalinesolutions
AT calvoej electrocatalysisofoxygenreductionatfe3o4oxideelectrodesinalkalinesolutions
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