The use of surface-enhanced resonance Raman spectroscopy and voltammetric techniques to investigate the catalytic reduction of oxygen with iron(III)tetra-4-N-methylpyridylporphine.
Item
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Title
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The use of surface-enhanced resonance Raman spectroscopy and voltammetric techniques to investigate the catalytic reduction of oxygen with iron(III)tetra-4-N-methylpyridylporphine.
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Identifier
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AAI9029970
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identifier
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9029970
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Creator
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Prashad-Rywkin, Shanti.
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Contributor
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Advisers: Ronald L. Birke | John R. Lombardi
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Date
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1990
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Analytical | Chemistry, Physical
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Abstract
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In this thesis SERRS and voltammetric techniques--CV, RDE and RRDE are used to elucidate the mechanism of oxygen reduction on a silver electrode with iron(III)-tetra-4-N-methylpyridylporphine. The results indicate that after the oxidation reduction cycle (ORC) at pH = 10 and 4 the iron porphyrin is adsorbed on the silver surface as a high spin, five coordinated {dollar}\mu{dollar}-oxo-bridged dimer. On the forward scan this dimer undergoes two successive one electron reductions at ca. {dollar}-0.3{dollar}V and {dollar}-0.5{dollar}V to form a high spin reduced Fe(II) {dollar}\mu{dollar}-oxo-bridged dimer.;On the reverse scan a two electron oxidation to the {dollar}\mu{dollar}-oxo Fe(III) dimer occurs. At pH = 2 only high spin reduced Fe(II) monomers are adsorbed on the surface.;At pH = 4 and 10, a shift in the reduction of the oxygen overpotential of ca. 150mV is observed and the active catalyst in this process is the partially reduced {dollar}\mu{dollar}-oxo dimer. A value of n = 4 was calculated for the number of electrons involved in this catalytic reaction. These results are used to formulate a mechanism for the catalytic reduction of oxygen.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
