Selective electrocatalysis of anodic oxygen-transfer reactions at chemically modified, thin-film lead dioxide electrodes

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6108392

Chang, Hsiangpin

The strategy to modify PbO{sub 2} electrodes for electrocatalysis of oxygen-transfer (O-t) reactions is to incorporate spatially separated catalytic sites into the PbO{sub 2} surface. The rate of OH radical formation is promoted at these sites, as is the rate of the O-t reaction, for the latter was demonstrated to be proportional to the former. The electrodeposition of PbO{sub 2} was studied as a special case of a heterogeneous O-t reaction. Soluble Pb(IV) species were detected with a rotated ring-disc electrode as intermediate products of the PbO{sub 2} deposition. Chemically modified PbO{sub 2} is electrodeposited by addition of Bi{sup 3+}, As(III), or Cl{sup {minus}} to the Pb{sup 2+} plating bath. The electrochemical stability and catalytic activity of the Bi-doped PbO{sub 2} (Bi-PbO{sub 2}) increase with increased Bi/Pb atomic ratio in the mixed oxide which were determined by X-ray photoelectron spectroscopy. An O-t mediation mechanism was proposed for the electrocatalysis observed at the chemically modified PbO{sub 2}. The catalysts serve as O-t mediators, which are different from electron-transfer mediators by not undergoing any redox change during the catalysis.

• Research Organization: Iowa State Univ. of Science and Technology, Ames, IA (USA)
• OSTI ID: 6108392
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COHERENT SCATTERING
DIFFRACTION
ELECTROCATALYSTS
ELECTRODES
ELECTRON SPECTROSCOPY
ELEMENTS
FILMS
HYDROXYL RADICALS
KINETICS
LEAD COMPOUNDS
LEAD OXIDES
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
RADICALS
REACTION KINETICS
SCATTERING
SPECTROSCOPY
THIN FILMS
X-RAY DIFFRACTION