Details
| Original language | English |
|---|---|
| Pages (from-to) | 164-175 |
| Number of pages | 12 |
| Journal | Journal of membrane science |
| Volume | 316 |
| Issue number | 1-2 |
| Early online date | 29 Sept 2007 |
| Publication status | Published - 15 May 2008 |
Abstract
For increased efficiency of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC), new types of membranes have to be developed. This approach has been realized by preparing hybrid membranes containing SO3H-functionalized mesoporous Si-MCM-41 as hydrophilic inorganic modifier in a polysiloxane matrix exhibiting sulfonic acid groups and basic heterocyclic groups like benzimidazole. The proton conductivity of sulfonated particles was modelled on the atomic scale in order to understand the influence of the density of sulfonic acid groups and of the presence of water molecules. The different hybrid membranes are characterized concerning their thermal stability, water uptake, and proton conductivity. Whereas the proton conductivity of well-established, but expensive and at >120 °C not long-time stable Nafion membranes continuously decreases with increasing temperature, the polysiloxane membranes, which suffer from a low-proton conductivity at around 100 °C, recover at about 120 °C due to intrinsic proton transport. At 180 °C the pure polysiloxane shows a proton conductivity which is only one order of magnitude lower than that of Nafion. Moreover, if the polysiloxane membrane contains additionally 10 wt.% of an SO3H-modified Si-MCM-41, the proton conductivity of such hybrid membrane at temperatures >180 °C and low relative humidity <10% is higher than that of Nafion membranes by a factor of 10.
Keywords
- Hybrid membrane, Inorganic particle, Polysiloxane, Proton conductivity, Proton transport simulation
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Materials Science(all)
- General Materials Science
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemical Engineering(all)
- Filtration and Separation
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In: Journal of membrane science, Vol. 316, No. 1-2, 15.05.2008, p. 164-175.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - New proton conducting hybrid membranes for HT-PEMFC systems based on polysiloxanes and SO3H-functionalized mesoporous Si-MCM-41 particles
AU - Wilhelm, Michaela
AU - Jeske, Michael
AU - Marschall, Roland
AU - Cavalcanti, Welchy Leite
AU - Tölle, Pia
AU - Köhler, Christof
AU - Koch, Dietmar
AU - Frauenheim, Thomas
AU - Grathwohl, Georg
AU - Caro, Jürgen
AU - Wark, Michael
PY - 2008/5/15
Y1 - 2008/5/15
N2 - For increased efficiency of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC), new types of membranes have to be developed. This approach has been realized by preparing hybrid membranes containing SO3H-functionalized mesoporous Si-MCM-41 as hydrophilic inorganic modifier in a polysiloxane matrix exhibiting sulfonic acid groups and basic heterocyclic groups like benzimidazole. The proton conductivity of sulfonated particles was modelled on the atomic scale in order to understand the influence of the density of sulfonic acid groups and of the presence of water molecules. The different hybrid membranes are characterized concerning their thermal stability, water uptake, and proton conductivity. Whereas the proton conductivity of well-established, but expensive and at >120 °C not long-time stable Nafion membranes continuously decreases with increasing temperature, the polysiloxane membranes, which suffer from a low-proton conductivity at around 100 °C, recover at about 120 °C due to intrinsic proton transport. At 180 °C the pure polysiloxane shows a proton conductivity which is only one order of magnitude lower than that of Nafion. Moreover, if the polysiloxane membrane contains additionally 10 wt.% of an SO3H-modified Si-MCM-41, the proton conductivity of such hybrid membrane at temperatures >180 °C and low relative humidity <10% is higher than that of Nafion membranes by a factor of 10.
AB - For increased efficiency of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC), new types of membranes have to be developed. This approach has been realized by preparing hybrid membranes containing SO3H-functionalized mesoporous Si-MCM-41 as hydrophilic inorganic modifier in a polysiloxane matrix exhibiting sulfonic acid groups and basic heterocyclic groups like benzimidazole. The proton conductivity of sulfonated particles was modelled on the atomic scale in order to understand the influence of the density of sulfonic acid groups and of the presence of water molecules. The different hybrid membranes are characterized concerning their thermal stability, water uptake, and proton conductivity. Whereas the proton conductivity of well-established, but expensive and at >120 °C not long-time stable Nafion membranes continuously decreases with increasing temperature, the polysiloxane membranes, which suffer from a low-proton conductivity at around 100 °C, recover at about 120 °C due to intrinsic proton transport. At 180 °C the pure polysiloxane shows a proton conductivity which is only one order of magnitude lower than that of Nafion. Moreover, if the polysiloxane membrane contains additionally 10 wt.% of an SO3H-modified Si-MCM-41, the proton conductivity of such hybrid membrane at temperatures >180 °C and low relative humidity <10% is higher than that of Nafion membranes by a factor of 10.
KW - Hybrid membrane
KW - Inorganic particle
KW - Polysiloxane
KW - Proton conductivity
KW - Proton transport simulation
UR - http://www.scopus.com/inward/record.url?scp=42949093307&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2007.09.037
DO - 10.1016/j.memsci.2007.09.037
M3 - Article
AN - SCOPUS:42949093307
VL - 316
SP - 164
EP - 175
JO - Journal of membrane science
JF - Journal of membrane science
SN - 0376-7388
IS - 1-2
ER -