Accession Number : AD0667716

Title :   OXIDATION OF HYDROGEN ON A PASSIVE PLATINUM ELECTRODE,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Schuldiner,Sigmund

Report Date : 27 FEB 1968

Pagination or Media Count : 10

Abstract : Under potentiostatic, steady-state conditions and at anodic potentials above 0.7 V (NHE), the rate of oxidation of molecular hydrogen decreases at a high-activity Pt electrode in 1M H2SO4. It is shown that this decrease is not owing to the formation of oxygen species on the electrode surface. It is believed that this passive behavior of Pt is due to anion adsorption - at least between 0.7 and 1.2 V. Depending on potential and previous potential sequence, passivity in this region is evidently sensitive to the amount of sulfate ion adsorbed, its heat of adsorption, and the presence of dermasorbed oxygen. At higher potentials both sorbed oxygen species and sulfate ion may be present and may contribute to the passivity. In the 0.7 to 1.2 V passive region, hydrogen oxidation is electrochemical. There is no significant chemical oxidation via an oxygen intermediate. (Author)

Descriptors :   (*FUEL CELLS, *ELECTRODES), (*PLATINUM, CATALYSIS), (*HYDROGEN, OXIDATION), ELECTROCHEMISTRY, SULFURIC ACID, REACTION KINETICS, ADSORPTION, SULFATES, OXIDES

Subject Categories : Physical Chemistry
      Electric Power Production and Distribution

Distribution Statement : APPROVED FOR PUBLIC RELEASE