Anodic oxygen-transfer electrocatalysis at pure and modified lead dioxide electrodes in acidic media

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5845080

Yeo, I H

Pure ..beta..-lead dioxide and lead dioxide doped heavily with other metal oxides were prepared by electrochemical deposition on a gold, rotated disc electrode (RDE) in 1.0 M HClO/sub 4/. These electrodes were compared for their electrocatalytic support of anodic reactions accompanied by transfer of oxygen from the aqueous solvent to the reaction product. The heterogeneous rate constants of several inorganic and organic reactions were determined. The electrocatalytic effects of numerous dopants were determined, and bismuth oxide was found to cause the greatest increase in rates of anodic oxygen-transfer reactions. Physical properties of the bismuth mixed lead oxide electrodes were examined by x-ray diffraction (XRD), Auger electron spectroscopy (AES), and scanning electron microscopy (SEM). The increased values of the heterogeneous rate constant for oxygen-transfer reactions caused by increased levels of bismuth in the mixed oxide electrodes was found to be accompanied by a decrease in the overpotential for anodic evolution of O/sub 2/. These kinetic properties also were found to be correlated with an increasing preferred orientation of the electrodeposited mixed oxide in which the (020) plane of the slightly distorted rutile structure was oriented parallel to the geometric surface of the disc electrode. The (020) plane has the highest ratio of oxygen:metal per unit area. A general mechanistic consideration is given for anodic oxygen-transfer electrocatalysis based on the increased activity of surface oxygen at the mixed oxide electrodes.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5845080
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
DOPED MATERIALS
ELECTRODES
ELEMENTS
GOLD
LEAD COMPOUNDS
LEAD OXIDES
MANGANESE
MATERIALS
METALS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
REDOX REACTIONS
SYNTHESIS
TRANSITION ELEMENTS