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...

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Autores principales:	Orive, A.G., Creus, A.H., Grumelli, D., Benitez, G.A., Andrini, L., Requejo, F.G., Bonazzola, C., Salvarezza, R.C.
Formato:	JOUR
Materias:	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
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_19327447_v113_n39_p17097_Orive
record_format	dspace
spelling	todo:paper_19327447_v113_n39_p17097_Orive2023-10-03T16:35:49Z Oxygen reduction on iron-melanin granular surfaces Orive, A.G. Creus, A.H. Grumelli, D. Benitez, G.A. Andrini, L. Requejo, F.G. Bonazzola, C. Salvarezza, R.C. 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. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar 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 Orive, A.G. Creus, A.H. Grumelli, D. Benitez, G.A. Andrini, L. Requejo, F.G. Bonazzola, C. Salvarezza, R.C. 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.
format	JOUR
author	Orive, A.G. Creus, A.H. Grumelli, D. Benitez, G.A. Andrini, L. Requejo, F.G. Bonazzola, C. Salvarezza, R.C.
author_facet	Orive, A.G. Creus, A.H. Grumelli, D. Benitez, G.A. Andrini, L. Requejo, F.G. Bonazzola, C. Salvarezza, R.C.
author_sort	Orive, A.G.
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
url	http://hdl.handle.net/20.500.12110/paper_19327447_v113_n39_p17097_Orive
work_keys_str_mv	AT oriveag oxygenreductiononironmelaningranularsurfaces AT creusah oxygenreductiononironmelaningranularsurfaces AT grumellid oxygenreductiononironmelaningranularsurfaces AT benitezga oxygenreductiononironmelaningranularsurfaces AT andrinil oxygenreductiononironmelaningranularsurfaces AT requejofg oxygenreductiononironmelaningranularsurfaces AT bonazzolac oxygenreductiononironmelaningranularsurfaces AT salvarezzarc oxygenreductiononironmelaningranularsurfaces
_version_	1807323967759843328

Oxygen reduction on iron-melanin granular surfaces

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