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ARTICLE
out using the four-probe current interruption method. The
dependence of the ionic conductivity versus DL was
examined.
IRAFC FCH-JU 245202 (2010–2012) and ‘‘Understanding the
Degradation Mechanisms of Membrane-Electrode-Assembly
for High Temperature PEMFCs and Optimization of the Individ-
ual Components’’ DEMMEA FCH-JU 245156 (2010-2012). Dr.
Maria Geormezi (Advent Technologies S.A., Greece) is also
thanked for performing the fuel cell tests.
Membrane, electrodes preparation, MEA fabrication and
testing. The phosphoric acid content in the membrane (196
wt %) was controlled by immersing a dry membrane in
ꢀ
H
3
PO
4
85 wt % for 2 days at 140 C. The phosphoric acid-
impregnated membrane was sandwiched between two Pt
electrodes where a certain amount of phosphoric acid was
sprayed onto the catalytic layer. In this work, the cathode
side and the anode side use the same electrodes with a cata-
REFERENCES AND NOTES
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Grove, W. R. Philos Mag J Sci 1839, 14, 127–130.
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VCH-Verlagsgesellschaft: Weinheim/Wiley, NY, 1996.
lyst loading 1.68 mg/cm and the hot pressing takes place at
ꢀ
3 Heinzel, A.; Hebling, C. Portable PEM systems, Chapter 82. In
Handbook of Fuel Cells: Fundamentals, Technology and Appli-
cations; Vielstien, W.; Gasteiger, H. A.; Lamm, A., Eds.; Vol. 4;
John Wiley & Sons, NY, 2003, pp 1142–1151.
1
50 C for 5 min. The hand-made electrodes were prepared
from ink by mixing the catalyst powder (30 wt % Pt/C, E-
Tek BASF Fuel Cell Division), the desired amount of polymeric
binder and dimethylacetamide (DMA) as solvent, on a gas dif-
fusion layer (GDL). GDL was homemade using carbon cloth
from E-Tek BASF Fuel Cell Division on which was sprayed a
slurry made of SAB carbon and PTFE dispersion, followed by
4
2
Ahmad, M. I.; Zaidi, S. M. J.; Rahman, S. U. Desalination
006, 193, 387–397.
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Kim, Y. S.; Wang, F.; Hickner, M.; McCartney, S.; Hong, Y. T.;
Harrison, W. T.; Azwodzinski, A.; McGrath, J. E. J Polym Sci
Part A: Polym Chem 2003, 41, 2264–2276.
ꢀ
sintering at 300 C under static air for 40 min. Finally, the
electrodes were heat treated under temperature and vacuum
to remove the organic solvent. Pure and dry hydrogen and air
gases were supplied to the anode and cathode compartments,
6 Sone, Y.; Ekdunge, P.; Simonsson, D. J Electrochem Soc
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7 Paddison, S. J. Annu Rev Mater Res 2003, 33, 289–319.
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respectively, for the operation of the cell at 160–180 C and at
8 Wainright, J. S.; Wang, J. T.; Savinell, R. F.; Litt, M.; Moad-
ambient pressure. The effective dimensions of electrodes were
del, H.; Rogers, C. Proc Electrochem Soc 1994, 94, 255–264.
2
5
ꢃ 5 cm , and the electrochemical evaluation was carried out
9 Fontanella, J. J.; Wintersgill, M. C.; Wainright, J. S.; Savinell,
R. F.; Litt, M. Electrochim Acta 1998, 43, 1289–1294.
in a single cell with serpentine flow channels (Fuel Cell Tech-
nologies). The measurements were made in two-electrode
arrangement. Polarization curves were recorded at different
temperatures using the potentiostat/galvanostat PGSTAT30
with the steady state current recorded for 30 s after each
10 Wang, J. T.; Lin, W. F.; Weber, M.; Wasmus, S.; Savinell, R.
F. Electrochim Acta 1998, 43, 3821–3828.
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87–299.
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2 Kawahara, M.; Morita, J.; Rikukawa, M.; Sanui, K.; Ogata, N.
potential was set. The electrochemical impedance spectra
2
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3 Li, Q.; Jensen, J. O.; Savinell, R. F.; Bjerrum, N. J. Prog
Polym Sci 2009, 34, 449–477.
(
EIS) were recorded at 0.2 A/cm in the frequency range of
1
1
1
0 mHz to 20 kHz with an amplitude of sinusoidal signal of
00 mA, using the same equipment.
1
4 Qian, G.; Benicewicz, B. C. J Polym Sci Part A: Polym Chem
2
009, 47, 4064–4073.
CONCLUSIONS
15 Li, Q. F.; Rudbeck, H. C.; Chromik, A.; Jensen, J. O.; Pan, C.;
Steenberg, T.; Calverley, M.; Bjerrum, N. J.; Kerres, J. J Membr
Sci 2010, 347, 260–270.
New aromatic polyether copolymers bearing polar pyridine
main chain groups combined with either non polar or polar
side chain ones, were synthesized. Optimization of the
copolymers composition and their preparation conditions
enabled the synthesis of soluble materials forming high qual-
ity films. Membranes prepared out of these materials were
tested in respect to their thermal and oxidative stability.
Even after prolonged treatment under strong oxidative con-
ditions, Fenton’s test, the membranes showed exceptional
stability. The study of their phosphoric acid uptake and of
their proton conductivity revealed that polymer electrolyte
membranes with conductivities well above 10 S/cm were
obtained. Finally, MEAs based on the p-tolyl bearing copoly-
mer were also fabricated and tested in a single fuel cell at
temperatures up to 180 C showing promising performance,
although the system is not yet optimized.
1
6 de Araujo, C. C.; Kreuer, K. D.; Schuster, M.; Portale, G.;
Mendil-Jakani, H.; Gebel, G.; Maier, J. Phys Chem Chem Phys
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7 Wen, S.; Gong, C.; Tsen, W. C.; Shu, Y. C.; Tsai, F. C. Int J
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2 Geormezi, M.; Deimede, V.; Gourdoupi, N.; Triantafyllopou-
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This work was financially supported by the European Commis-
sion through the programs ‘‘Development of an Internal
Reforming Alcohol High Temperature PEM Fuel Cell Stack’’
2
3 Gourdoupi, N.; Papadimitriou, K.; Neophytides, S.; Kallitsis,
J. K. Fuel Cells 2008, 3–4, 200–208.
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