Accession Number : AD0461758

Title :   ELECTROCHEMISTRY OF FUEL CELL ELECTRODES. HYDROGEN OVERVOLTAGE AT A DROPPING THALLIUM AMALGAM ELECTRODE.

Descriptive Note : Technical memo.,

Corporate Author : TYCO LABS INC WALTHAM MA

Personal Author(s) : Butler, James N. ; Barron-Apps, Evelyn A. ; Meehan, Mary L.

Report Date : MAR 1965

Pagination or Media Count : 1

Abstract : Measurements were made of hydrogen overvoltage, in 0.1 M HClO4, at temperatures from 14 to 69 C, at dropping amalgam electrodes containing 10.0 and 40.6 mole percent thallium. The overvoltage was 20 to 30 millivolts higher on 40% Tl amalgam than on mercury. When corrections were made for the effect of the diffuse double layer, the exchange current for hydrogen discharge at 25 C was found to decrease by a factor of 2 on going from Hg to 40% Tl amalgam. The temperature dependence of overvoltage gives an enthalpy of activation (extrapolated to the reversible hydrogen potential) of 22.3 = 0.4, 21.2 = 1.1, and 23.1 = 0.3 kcal/mole for Hg, 10% Tl amalgam, and 40% Tl amalgam respectively. Thus, both the overvoltage and the enthalpy of activation are higher on Tl amalgams than on Hg. (Author)

Descriptors :   (*FUEL CELLS, ELECTRODES), (*ELECTRODES, FUEL CELLS), (*THALLIUM ALLOYS, MERCURY ALLOYS), ELECTROCHEMISTRY, VOLTAGE, HYDROGEN, ELECTRIC DISCHARGES, THERMODYNAMICS, REACTION KINETICS, ELECTRIC CURRENT, HEAT OF ACTIVATION, MATHEMATICAL ANALYSIS, EQUATIONS, TABLES(DATA).

Distribution Statement : APPROVED FOR PUBLIC RELEASE