The Formation of Adsorbed O(2-) and OH(-) on a Ag Electrode in Dilute CrO4(-2) Electrolytes

The Formation of Adsorbed O(2-) and OH(-) on a Ag Electrode in Dilute CrO4(-2) Electrolytes

Surface enhanced Raman scattering has been used to detect in situ the formation of O= and OH- adsorbed on a Ag electrode in an aqueous solution of 25 micromolar Na2Cr2O7 and .01 to .001 M KC1. Both oxide and hydroxide adsorbates are observed after completion of an oxidation-reduction cycle in a stan...

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Bibliographische Detailangaben
Hauptverfasser: Dorain, Paul B, Bates, Jennifer L
Format: Report
Sprache:eng
Schlagworte:
ABSORBERS(MATERIALS)
CATALYSIS
CHROMATES
CYCLES
ELECTRODES
ELECTROLYTIC CELLS
HYDROXIDES
LIGHT SCATTERING
METALS
OXIDATION REDUCTION REACTIONS
OXIDES
PASSIVITY
Physical Chemistry
RAMAN SPECTRA
SILVER
SOLUTIONS(MIXTURES)
SURFACES
VOLTAGE
VOLTAMMETRY
WATER
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Beschreibung
Zusammenfassung:Surface enhanced Raman scattering has been used to detect in situ the formation of O= and OH- adsorbed on a Ag electrode in an aqueous solution of 25 micromolar Na2Cr2O7 and .01 to .001 M KC1. Both oxide and hydroxide adsorbates are observed after completion of an oxidation-reduction cycle in a standard voltammetry experiment. As the Ag electrode voltage is swept cathodically, the O=ads is protonated to form more OH-ads but, unlike in MnO4- solutions, no further protonation to form H20 occurs at any cell voltage. The addition of O2 gas to the electrolyte deprotonates the adsorbed OH- to form an oxide covered surface. These results for CrO4 solutions are contrasted with previous results for MnO4 electrolytes to obtain information about the nature of the metal-solution interface in chromate passivated metal surfaces. Keywords: Catalysis, Passivation, Metal surfaces, Protonation, Metal oxide absorbates, Silver, Electrodes, Hydroxides.