Accession Number : AD0440751

Title :   ELECTROCHEMISTRY OF FUEL CELL ELECTRODES HYDROGEN EVOLUTION AT A SOLID INDIUM ELECTRODE,

Corporate Author : TYCO LABS INC WALTHAM MA

Personal Author(s) : Butler, James N. ; Dienst, Manfred

Report Date : APR 1964

Pagination or Media Count : 42

Abstract : Measurements of hydrogen overvoltage on solid indium electrodes were made in 0.1 molar HClO4 at temperatures from 21 C to 59.5 C. The slow step in the hydrogen evolution reaction is probably discharge of a hydrogen ion, as indicated by the exchange current transfer coefficient (0.5), effect of added iodide ion, and effect of acid concentration. The enthalpy of activation is 14.1 = 0.5 kcal/mole at the reversible hydrogen potential and 10.0 = 0.2 kcal/mole at the zero-charge point. From these values, an estimate of 50 = 10 kcal/g atom is obtained for the heat of adsorption of hydrogen atoms on indium. The reaction is very sensitive to traces of oxygen, and the formation and removal of oxide films is discussed. (Author)

Descriptors :   (*FUEL CELLS, ELECTRODES), (*ELECTRODES, INDIUM), ENTHALPY, TEMPERATURE, HYDROGEN, IONS, IODIDES, ELECTROCHEMISTRY.

Distribution Statement : APPROVED FOR PUBLIC RELEASE