Long-term stability of nanostructured thin film electrodes at operating potentials
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- 3M Fuel Cell Components Program, St. Paul, MN (United States)
Long-term stability of nanostructured thin film (NSTF) catalysts at operating potentials has been investigated. Compared to high surface area Pt/C catalysts, NSTF electrodes show 20-50x smaller F- emission rates (FER) because of their high specific activity for oxygen reduction reaction (ORR), but are susceptible to poisoning by the products of membrane degradation because of their low electrochemically active surface area (ECSA). The observed voltage degradation rates at potentials corresponding to 1-1.5 A/cm2 current density are much higher than the allowable 13-14 µV/h. Although F- is not itself responsible for performance decay, cumulative fluoride release (CFR) is a good marker for catalyst surface contamination. The observed performance decay is not only due to loss of active Pt sites but also adsorbed impurities impeding ORR kinetics. There is a strong correlation between measured CFR and observed decrease in specific ORR activity and limiting current density and increase in mass transfer overpotentials. The correlations indicate that the target of <10% lifetime performance degradation can be achieved by restricting CFR in NSTF electrodes to 0.7 µg/cm2 , as may be possible with more stable membranes, higher surface area NSTF catalysts, and cell operation at lower temperatures and higher relative humidities.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Hydrogen Fuel Cell Technologies Office
- Grant/Contract Number:
- AC05-00OR22725; AC02-06CH11357
- OSTI ID:
- 1345010
- Alternate ID(s):
- OSTI ID: 1373711
- Journal Information:
- Journal of the Electrochemical Society, Vol. 164, Issue 4; ISSN 0013-4651
- Publisher:
- The Electrochemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Fuel Cell Performance Implications of Membrane Electrode Assembly Fabrication with Platinum-Nickel Nanowire Catalysts
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journal | January 2018 |
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