Oxygen reduction on iron-melanin granular surfaces
We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that t...
Guardado en:
Publicado: |
2009
|
---|---|
Materias: | |
Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive |
Aporte de: |
id |
paper:paper_19327447_v113_n39_p17097_Orive |
---|---|
record_format |
dspace |
spelling |
paper:paper_19327447_v113_n39_p17097_Orive2023-06-08T16:31:28Z Oxygen reduction on iron-melanin granular surfaces Alkaline solutions Catalytic activity Dopaminergic neurons Electrocatalytic activity Eumelanins EXAFS Four electrons Granular deposits Hydroxyl species IR spectroscopy Lipid peroxidation Neurodegeneration Oxygen Reduction Quinone groups Voltammetric data XANES XPS Catalyst activity Deposits Electrocatalysis Electrochemical sensors Electrolytic reduction Graphite Iron compounds Neurons Oxygen Physical chemistry Iron deposits We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that the iron-eumelanin system exhibits higher electrocatalytic activity than quinone/hydroquinone films (Q/QH) on the same substrate. In contrast to Q/QH deposits, the iron-containing eumelanin system is able to reduce oxygen with transfer of four electrons, thus allowing the formation of reactive hydroxyl species. Our results can explain the physical chemistry basis of the oxygen-radical induced lipid peroxidation and consequent neurodegeneration of the melanin-containing dopaminergic neurons observed by several authors. © 2009 American Chemical Society. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive |
institution |
Universidad de Buenos Aires |
institution_str |
I-28 |
repository_str |
R-134 |
collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
topic |
Alkaline solutions Catalytic activity Dopaminergic neurons Electrocatalytic activity Eumelanins EXAFS Four electrons Granular deposits Hydroxyl species IR spectroscopy Lipid peroxidation Neurodegeneration Oxygen Reduction Quinone groups Voltammetric data XANES XPS Catalyst activity Deposits Electrocatalysis Electrochemical sensors Electrolytic reduction Graphite Iron compounds Neurons Oxygen Physical chemistry Iron deposits |
spellingShingle |
Alkaline solutions Catalytic activity Dopaminergic neurons Electrocatalytic activity Eumelanins EXAFS Four electrons Granular deposits Hydroxyl species IR spectroscopy Lipid peroxidation Neurodegeneration Oxygen Reduction Quinone groups Voltammetric data XANES XPS Catalyst activity Deposits Electrocatalysis Electrochemical sensors Electrolytic reduction Graphite Iron compounds Neurons Oxygen Physical chemistry Iron deposits Oxygen reduction on iron-melanin granular surfaces |
topic_facet |
Alkaline solutions Catalytic activity Dopaminergic neurons Electrocatalytic activity Eumelanins EXAFS Four electrons Granular deposits Hydroxyl species IR spectroscopy Lipid peroxidation Neurodegeneration Oxygen Reduction Quinone groups Voltammetric data XANES XPS Catalyst activity Deposits Electrocatalysis Electrochemical sensors Electrolytic reduction Graphite Iron compounds Neurons Oxygen Physical chemistry Iron deposits |
description |
We report the catalytic activity of iron-eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron-melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that the iron-eumelanin system exhibits higher electrocatalytic activity than quinone/hydroquinone films (Q/QH) on the same substrate. In contrast to Q/QH deposits, the iron-containing eumelanin system is able to reduce oxygen with transfer of four electrons, thus allowing the formation of reactive hydroxyl species. Our results can explain the physical chemistry basis of the oxygen-radical induced lipid peroxidation and consequent neurodegeneration of the melanin-containing dopaminergic neurons observed by several authors. © 2009 American Chemical Society. |
title |
Oxygen reduction on iron-melanin granular surfaces |
title_short |
Oxygen reduction on iron-melanin granular surfaces |
title_full |
Oxygen reduction on iron-melanin granular surfaces |
title_fullStr |
Oxygen reduction on iron-melanin granular surfaces |
title_full_unstemmed |
Oxygen reduction on iron-melanin granular surfaces |
title_sort |
oxygen reduction on iron-melanin granular surfaces |
publishDate |
2009 |
url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v113_n39_p17097_Orive http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive |
_version_ |
1768542665766338560 |