TY  - JOUR
AU  - Appel, Marina
AU  - Borisov, Galin
AU  - Holderer, Olaf
AU  - Appavou, Marie-Sousai
AU  - Zorn, Reiner
AU  - Lehnert, Werner
AU  - Richter, Dieter
TI  - Proton diffusion in the catalytic layer for high temperature polymer electrolyte fuel cells
JO  - RSC Advances
VL  - 9
IS  - 6
SN  - 2046-2069
CY  - London
PB  - RSC Publishing
M1  - FZJ-2019-05675
SP  - 37768
PY  - 2019
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000501604800010
DO  - DOI:10.1039/c9ra06431a
UR  - https://juser.fz-juelich.de/record/866594
ER  -