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Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy

Chemical reduction of dioxygen in organic solvents for the production of reactive oxygen species or the concomitant oxidation of organic substrates can be enhanced by the separation of products and educts in biphasic liquid systems. Here, the coupled electron and ion transfer processes is studied as...

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Autores principales: Rastgar, Shokoufeh, Teixeira Santos, Keyla, Angelucci, Camilo Andrea, Wittstock, Gunther
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7496973/
https://www.ncbi.nlm.nih.gov/pubmed/32460434
http://dx.doi.org/10.1002/chem.202001967
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author Rastgar, Shokoufeh
Teixeira Santos, Keyla
Angelucci, Camilo Andrea
Wittstock, Gunther
author_facet Rastgar, Shokoufeh
Teixeira Santos, Keyla
Angelucci, Camilo Andrea
Wittstock, Gunther
author_sort Rastgar, Shokoufeh
collection PubMed
description Chemical reduction of dioxygen in organic solvents for the production of reactive oxygen species or the concomitant oxidation of organic substrates can be enhanced by the separation of products and educts in biphasic liquid systems. Here, the coupled electron and ion transfer processes is studied as well as reagent fluxes across the liquid|liquid interface for the chemical reduction of dioxygen by decamethylferrocene (DMFc) in a dichloroethane‐based organic electrolyte forming an interface with an aqueous electrolyte containing alkali metal ions. This interface is stabilized at the orifice of a pipette, across which a Galvani potential difference is externally applied and precisely adjusted to enforce the transfer of different alkali metal ions from the aqueous to the organic electrolyte. The oxygen reduction is followed by H(2)O(2) detection in the aqueous phase close to the interface by a microelectrode of a scanning electrochemical microscope (SECM). The results prove a strong catalytic effect of hydrated alkali metal ions on the formation rate of H(2)O(2), which varies systematically with the acidity of the transferred alkali metal ions in the organic phase.
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spelling pubmed-74969732020-09-25 Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy Rastgar, Shokoufeh Teixeira Santos, Keyla Angelucci, Camilo Andrea Wittstock, Gunther Chemistry Full Papers Chemical reduction of dioxygen in organic solvents for the production of reactive oxygen species or the concomitant oxidation of organic substrates can be enhanced by the separation of products and educts in biphasic liquid systems. Here, the coupled electron and ion transfer processes is studied as well as reagent fluxes across the liquid|liquid interface for the chemical reduction of dioxygen by decamethylferrocene (DMFc) in a dichloroethane‐based organic electrolyte forming an interface with an aqueous electrolyte containing alkali metal ions. This interface is stabilized at the orifice of a pipette, across which a Galvani potential difference is externally applied and precisely adjusted to enforce the transfer of different alkali metal ions from the aqueous to the organic electrolyte. The oxygen reduction is followed by H(2)O(2) detection in the aqueous phase close to the interface by a microelectrode of a scanning electrochemical microscope (SECM). The results prove a strong catalytic effect of hydrated alkali metal ions on the formation rate of H(2)O(2), which varies systematically with the acidity of the transferred alkali metal ions in the organic phase. John Wiley and Sons Inc. 2020-07-23 2020-08-21 /pmc/articles/PMC7496973/ /pubmed/32460434 http://dx.doi.org/10.1002/chem.202001967 Text en © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Full Papers
Rastgar, Shokoufeh
Teixeira Santos, Keyla
Angelucci, Camilo Andrea
Wittstock, Gunther
Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title_full Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title_fullStr Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title_full_unstemmed Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title_short Catalytic Activity of Alkali Metal Cations for the Chemical Oxygen Reduction Reaction in a Biphasic Liquid System Probed by Scanning Electrochemical Microscopy
title_sort catalytic activity of alkali metal cations for the chemical oxygen reduction reaction in a biphasic liquid system probed by scanning electrochemical microscopy
topic Full Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7496973/
https://www.ncbi.nlm.nih.gov/pubmed/32460434
http://dx.doi.org/10.1002/chem.202001967
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