Accession Number : AD0747766

Title :   Electrocatalysis of Oxygen Reduction by the Tungsten Bronzes.

Descriptive Note : Rept. no. 8 (Final), 1 Sep 67-31 Dec 72,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA ELECTROCHEMISTRY LAB

Personal Author(s) : McHardy,J. ; Mittal,K. L. ; Bockris,J. O'M.

Report Date : DEC 1971

Pagination or Media Count : 92

Abstract : The rate of oxygen reduction to water at a given potential on a crystal of the non-stoichiometric compound sodium tungsten bronze, Na(x)WO3 was studied. It was found to be accelerated several thousand times by the presence of 400 ppm of platinum in the bronze. In the vicinity of the reversible oxygen electrode potential, the crystal loses sodium by anodic dissolution, producing a thin semiconducting layer on the surface. Of several possible models that might account for the effect of platinum upon catalysis, only one--based on a synergistic phenomenon known as 'spillover'--was consistent with all the experimental observations. Hole injection during reduction of these reactive species may account for the enhanced rate of sodium dissolution from crystals containing platinum. (Author)

Descriptors :   (*OXYGEN, *REDUCTION(CHEMISTRY)), (*CATALYSTS, TUNGSTEN COMPOUNDS), (*ELECTRODES, TUNGSTEN COMPOUNDS), CATALYSTS, WATER, PLATINUM, DOPING, SURFACES, OXIDES, TUNGSTEN COMPOUNDS, SODIUM COMPOUNDS, SEMICONDUCTORS, BAND THEORY OF SOLIDS, SINGLE CRYSTALS

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE