CeO 2 , ZrO 2 and YSZ as mitigating additives against degradation of proton exchange membranes by free radicals
| Autor: | Thomas Weissbach, Timothy J. Peckham, Steven Holdcroft |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Proton exchange membrane fuel cell Filtration and Separation 02 engineering and technology Sulfonic acid 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Biochemistry 0104 chemical sciences chemistry.chemical_compound Membrane chemistry Chemical engineering Nafion Reagent General Materials Science Physical and Theoretical Chemistry 0210 nano-technology Ionomer Yttria-stabilized zirconia |
| Zdroj: | Journal of Membrane Science. 498:94-104 |
| ISSN: | 0376-7388 |
| DOI: | 10.1016/j.memsci.2015.10.004 |
| Popis: | The effect of CeO 2 and ZrO 2 on the durability of perfluorinated sulfonic acid ionomer membranes in proton exchange membrane fuel cells is widely discussed in the literature and their effectiveness is shown. However, in-situ fuel cell testing is a time consuming, costly process, and it is beneficial to develop representative ex-situ analyses that allow for rapid screening and ranking of additives in their ability to mitigate degradation. In this work, we investigate the reaction of perfluorosulfonic acid (PFSA) ionomer to radicals generated using Fenton’s reagent and draw the conclusion that this widely-employed ex-situ degradation technique leads to an extraordinarily large and unrealistic accumulation of iron species in the membrane. In response, we developed an ex-situ degradation procedure in which membranes are cast from Nafion ® D2020 solutions containing FeSO 4 and subsequently exposed to only aqueous H 2 O 2 solution (thus maintaining a constant, representative Fe 2+/3+ content in the membrane). Nafion ® D2020 was also co -cast with up to 10 wt% of CeO 2 , ZrO 2 and yttria-stabilized zirconia (YSZ). Using this protocol, it is found that CeO 2 -containing membranes reduce fluoride release, mass loss, and loss of sulfonic acid groups compared to pristine Nafion membranes, or membranes containing ZrO 2 or YSZ. |
| Databáze: | OpenAIRE |
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