Fuel cell cathode studies in aqueous K sub 2 CO sub 3 and KOH

Journal Article · Wed Oct 31 23:00:00 EST 1990 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2086222· OSTI ID:5556747

Striebel, K A; McLarnon, F R; Cairns, E J ^[1]

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1. Applied Science Div., Lawrence Berkeley Lab., Dept. of Chemical Engineering, Univ. of California, Berkeley, CA (US)

This paper reports on the galvanostatic steady-state performance of PTFE-bonded Pt-on-carbon gas diffusion electrodes (GDEs) has been measured with variable oxygen partial pressures in 2 to 11 {ital M} KOH and 2 to 5.5 {ital M} K{sub 2}CO{sub 3}. The catalyst in the porous electrodes was characterized with cyclic voltammetry in a special cell with low uncompensated solution resistance. Cyclic voltammograms yielded measurements of the wetted areas of carbon and Pt and the local electrolyte composition. Conditions for differences in the area of Pt wetted by the KOHG electrolyte collapsed oxygen reduction (OR) performance curves for several different electrodes into a single curve of log-specific current density vs. potential. Comparisons with kinetic results suggest that OR on carbon contributes to the high current densities in 6.9 {ital M} KOH at high overpotentials. In K{sub 2}CO{sub 3} electrolyte, current density was found to be proportional to the square root of both wetted Pt area and O{sub 2} pressure, indicating that mass-transfer rates were not limited by O{sub 2} transport.

• OSTI ID: 5556747
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 137:11; ISSN 0013-4651; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300502* -- Fuel Cells-- Performance & Testing
300503 -- Fuel Cells-- Materials
Components
& Auxiliaries
300505 -- Fuel Cells-- Electrochemistry
Mass Transfer & Thermodynamics
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
CARBON
CARBON COMPOUNDS
CARBONATES
CATHODES
CURRENT DENSITY
DIFFUSION
DIRECT ENERGY CONVERTERS
DISPERSIONS
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
ELEMENTS
FUEL CELLS
HYDROGEN COMPOUNDS
HYDROXIDES
HYSTERESIS
MASS TRANSFER
METALS
MIXTURES
NONMETALS
OXYGEN
OXYGEN COMPOUNDS
PARTIAL PRESSURE
PERFORMANCE TESTING
PLATINUM
PLATINUM METALS
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
SOLUTIONS
TESTING
TRANSITION ELEMENTS
VOLTAMETRY