Oxygen reduction on carbon-supported platinum fuel-cell electrodes in H/sub 3/PO/sub 4/
The reduction of oxygen on carbon supported fuel cell electrodes was investigated in phosphoric acid electrolytes in the concentration range of 85% to 101% and at temperatures from 25/sup 0/ to 180/sup 0/C. In purified acid the Tafel slope in the potential region of 0.7 to 0.9 V RHE is approx. 120 mV/decade and is invariant with temperature. The activation energy for oxygen reduction is between 8 kcal and 13 kcal/mole. In impure 101% electrolyte the Tafel slope increases from a value of 85 mV/decade at 80/sup 0/C to 105 mV/decade at 180/sup 0/C and the activation energy is 18.29 kcal/mole. The major discrepancies in the literature can be rationalized on the basis of impurity effects. In pure electrolytes, the kinetic parameters on smooth platinum and high area carbon supported platinum are the same.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6467568
- Report Number(s):
- BNL-29788; CONF-8105105-2; ON: DE81027303
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
300503 -- Fuel Cells-- Materials
Components
& Auxiliaries
300505* -- Fuel Cells-- Electrochemistry
Mass Transfer & Thermodynamics
ACID ELECTROLYTE FUEL CELLS
CARBON
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CATHODES
CHEMICAL REACTIONS
CHEMISTRY
DIRECT ENERGY CONVERTERS
ELECTROCATALYSTS
ELECTROCHEMICAL CELLS
ELECTROCHEMISTRY
ELECTRODES
ELEMENTS
FUEL CELLS
HYDROGEN COMPOUNDS
IMPURITIES
INORGANIC ACIDS
METALS
NONMETALS
OVERVOLTAGE
OXYGEN
PERFORMANCE
PHOSPHORIC ACID
PLATINUM
PLATINUM METALS
REDUCTION
TRANSITION ELEMENTS
VOLTAMETRY