20.500.12556/RUL-126392 Holistic approach to chemical degradation of Nafion membranes in fuel cells modelling and predictions The state of health of polyfluorinated sulfonic-acid ionomer membranes (e.g. Nafion) in low-temperature proton exchange membrane fuel cells (LT-PEMFCs) is negatively influenced by degradation phenomena occurring during their operation. As a consequence, the performance and durability of the membrane are decreased. In this article, we focus on simulating and predicting chemical membrane degradation phenomena using a holistic zero-dimensional kinetic framework. The knowledge of chemical degradation mechanisms is widely spread. We have collected and evaluated an extensive set of chemical mechanisms to achieve a holistic approach. This yields a set of 23 coupled chemical equations, which provide the whole cause and effect chain of chemical degradation in LT-PEMFCs (based on the Fenton reaction between Fe [sup] 2+ and H [sub] 2O [sub] 2 via the attack of hydroxyl radicals on the membrane, loss of ionomer moieties and emission of fluoride). Our kinetic framework allows the reproduction of experimentally accessible data such as fluoride emission rates and concentrations of ionomer moieties (from both in situ and ex situ tests). We present an approach, which allows estimations of the membrane lifetime based on fluoride emission rates. In addition, we outline the demetallation of Fe-N-C catalysts as a source of additional harmful iron species, which accelerate chemical membrane degradation. To demonstrate the expandability and versatility of the kinetic framework, a set of five chemical equations describing the radical scavenging properties of cerium agents is coupled to the main framework and its influence on membrane degradation is analysed. An automated solving routine for the system of coupled chemical equations on the basis of the chemical kinetic simulation tool COPASI has been developed and is freely accessible online (http://ptc-pc-139.tugraz.at/ cgi-bin/Membrane_Degradation/). fuel cell modelling proton exchange membrane gorivne celice modeliranje protonska izmenjevalna membrana true false true Angleški jezik Slovenski jezik Članek v reviji 2021-04-19 23:41:17 2021-04-19 23:41:20 2022-09-05 03:55:03 0000-00-00 00:00:00 2020 0 0 Str. 5647-5666 art. 5647 Vol. 22 2020 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 621.352.6(045) 1463-9076 10.1039/C9CP04986J 17051931 RAZ_Fruhwirt_Philipp_2020.pdf RAZ_Fruhwirt_Philipp_2020.pdf 1 A1A48BABDCCAB2F5904C900A042AF6F1 8a442cb23009002689d0bbb1aabe6d1b99dbb3f815b71e5980d4fadac1cd74f8 e6787cc2-a1bb-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=142335 https://pubs.rsc.org/en/content/articlehtml/2020/cp/c9cp04986j 1 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=142334 Fakulteta za strojništvo 0 0 0