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Kinetic Modeling
of Platinum Surface Area Loss
in
PEMFCs
Ted Holby,
Dane Morgan, Materials Science Program
Polymer electrolyte
membrane fuel cells (PEMFCs) are a promising
technology for future energy conversion
devices. Platinum surface area loss is a key
issue in the long-term durability of PEMFCs.
This loss is thought to be due to Oswald
ripening, platinum dissolution, particle surface
migration and coalescence (the Smoluchowski
mechanism) and degradation of the particles’
underlying carbon support. By kinetically
modeling these underlying mechanisms that lead
to loss in platinum surface area, we hope to
gain insight into which mechanisms dominate
under different PEMFC simulated run time
conditions. Parameters for models come from
first-principle studies of platinum and carbon
surfaces as well as from fitting to experimental
loss data.
Figure: Picture of platinum monomers on a
graphite surface. First principle energy
calculations help to elucidate hopping barriers
and pathways.
We gratefully
acknowledge financial support from the
Department of Energy (DOE) Basic Research for
the Hydrogen Fuel Initiative, award number
DE-FG02-05ER15728. We gratefully acknowledge
computing support from the National Science
Foundation (NSF) National Center for
Supercomputing Applications (NCSA), award number
DMR060007
-
Instability of Supported Platinum
Nanoparticles in Low-Temperature Fuel Cells,
Y. Shao-Horn, W.C. Sheng, S. Chen, P.J.
Ferreira, E.
Holby,
D. Morgan,
Topics
in Catalysis
2007, 46, 3-4,
1572-9028
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