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Modeling of Catalyst Surface Area
Loss in PEMFC Cathodes
Ted Holby,
Dane Morgan, Materials Science Program
Polymer electrolyte
membrane fuel cells (PEMFCs) are a promising
technology for future energy conversion devices.
Loss of precious metal nanoparticle catalyst
specific surface area (ESA) is a key issue in
the long-term durability of PEMFC cathodes. This
loss is attributed to Ostwald ripening, precious
metal dissolution, particle surface migration
and coalescence, and degradation of the
particles’ underlying carbon support. We have
developed a thermo-kinetic model that helps
explain the roles of the particle size
distribution and crossover H2 from the fuel cell
anode on this ESA loss1. We have found that the
formation of oxide(s) on the particle surfaces
is likely to play an important roll in ESA loss
and future studies are aimed at elucidating this
role.
Figure:
Pictorial display of mechanisms
included in the thermo-kinetic model.
We gratefully acknowledge
financial support from the Department of Energy
(DOE) Basic Research for the Hydrogen Fuel
Initiative, award number DE-FG02-05ER15728 and
DE-FG01-04ER04-20. We gratefully acknowledge
computing support from the National Science
Foundation (NSF) National Center for
Supercomputing Applications (NCSA), award number
DMR060007
Publication
-
Pt Nanoparticle Stability in
PEM Fuel Cells: Influence of Particle Size
Distribution and Crossover Hydrogen,
E.F. Holby, W.C. Sheng, Y. Shao-Horn, D.
Morgan, Energy Environ. Sci., DOI:
10.1039/b821622n (2009).
-
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, 46
285-305 (2007).
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