Surface protonation and electrochemical activity of oxides in aqueous solution

Journal Article · Wed Mar 14 00:00:00 EST 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00162a006· OSTI ID:6520795

Goodenough, J B; Manoharan, R; Paranthaman, M ^[1]

---

1. Univ. of Texas, Austin (USA)

Measurements of the pH dependence of the surface-charge density on oxide particles are correlated with the pH dependence of the cyclic voltammograms and of the chemical activity of the oxide for electrolysis/fuel cell reactions. Studies of the pyrochlores Pb{sub 2}M{sub 2{minus}x}Pb{sub x}O{sub 7{minus}y} and the rutiles in MO{sub 2} (M = Ru or Ir) and of the perovskite Sr{sub 1{minus}x}NbO{sub 3{minus}{delta}} show that (1) the oxygen-reduction reaction, found on the pyrochlores in alkaline solution, occurs by exchange of a surface OH{sup {minus}} species at an O{prime} site with an adsorbed O{sub 2}{sup {minus}} solution species, (2) the oxygen-evolution and chlorine-evolution reactions occur at a surface O{sup {minus}} species made accessible by surface oxidation of a redox couple lying close to the top of the O{sup 2{minus}}:2p{sup 6} valence band, and (3) the hydrogen-evolution reaction occurs at the surface OH{sub 2} species bonded to cations with a surface redox couple lying close to the H{sup +}/H{sub 2} level in solution.

• OSTI ID: 6520795
• Journal Information: Journal of the American Chemical Society; (USA), Vol. 112:6; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
OXIDES
ELECTROCHEMISTRY
SURFACE PROPERTIES
CHARGE DENSITY
DATA ANALYSIS
ELECTROLYSIS
EXPERIMENTAL DATA
FUEL CELLS
IRIDIUM
MEASURING INSTRUMENTS
MEASURING METHODS
RUTHENIUM
CHALCOGENIDES
CHEMISTRY
DATA
DIRECT ENERGY CONVERTERS
ELECTROCHEMICAL CELLS
ELEMENTS
INFORMATION
LYSIS
METALS
NUMERICAL DATA
OXYGEN COMPOUNDS
PLATINUM METALS
TRANSITION ELEMENTS
360204* - Ceramics
Cermets
& Refractories- Physical Properties