INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Oxygen Reduction on Iron-Melanin Granular Surfaces
Autor/es:
A. GONZÁLEZ ORIVE ,; A. HERNÁNDEZ CREUS; D. GRUMELLI; G. BENITEZ; L. ANDRINI; F. G.REQUEJO; C. BONAZZOLA; R.C. SALVAREZZA
Revista:
JOURNAL OF PHYSICAL CHEMISTRY C
Editorial:
AMER CHEMICAL SOC
Referencias:
Año: 2009 vol. 113 p. 17097 - 17103
ISSN:
1932-7447
Resumen:
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.-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.-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.-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.