This title appears in the Scientific Report :
2019
Please use the identifier:
http://dx.doi.org/10.1039/c9ra06431a in citations.
Please use the identifier: http://hdl.handle.net/2128/23572 in citations.
Proton diffusion in the catalytic layer for high temperature polymer electrolyte fuel cells
Proton diffusion in the catalytic layer for high temperature polymer electrolyte fuel cells
The present study focuses on quasielastic neutron scattering (QENS) of the proton dynamics in phosphoric acid (PA) inside the catalytic layer of high-temperature polymer electrolyte fuel cells (HT-PEFCs). The nanosecond proton dynamics is investigated on the local length scale around operating tempe...
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Personal Name(s): | Appel, Marina |
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Borisov, Galin / Holderer, Olaf (Corresponding author) / Appavou, Marie-Sousai / Zorn, Reiner / Lehnert, Werner / Richter, Dieter | |
Contributing Institute: |
JCNS-FRM-II; JCNS-FRM-II Heinz Maier-Leibnitz Zentrum; MLZ Streumethoden; JCNS-2 Neutronenstreuung; JCNS-1 Technoökonomische Systemanalyse; IEK-3 |
Published in: | RSC Advances, 9 (2019) 6, S. 37768 |
Imprint: |
London
RSC Publishing
2019
|
DOI: |
10.1039/c9ra06431a |
Document Type: |
Journal Article |
Research Program: |
Soft Matter, Health and Life Sciences Fuel Cells FRM II / MLZ |
Subject (ZB): | |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/23572 in citations.
The present study focuses on quasielastic neutron scattering (QENS) of the proton dynamics in phosphoric acid (PA) inside the catalytic layer of high-temperature polymer electrolyte fuel cells (HT-PEFCs). The nanosecond proton dynamics is investigated on the local length scale around operating temperatures (300 K–430 K) using neutron backscattering spectroscopy. We have investigated the catalyst doped with different amounts of PA in order to understand the distribution of PA inside the layer. Three approaches are considered for the description of proton dynamics: the random jump diffusion model, distribution of diffusion constants and, finally, the trap model. Due to adsorption of the PA on the Pt particles the diffusion of protons in the catalytic layer is different in comparison to the bulk acid. The proton dynamics in the catalytic layer can be described by the random jump diffusion with traps. This diffusion is significantly slower than the diffusion of free PA; this also results in a lower conductivity, which is estimated from the obtained diffusion constant. |