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DOE OSTI · 2375412

Ultraviolet-Activated Solid-State Nitrene Cross-Linking: A Scalable Pathway to Prolonged Lifespan in Anion Exchange Membranes

Clemens, Auston L.·Cerón, Maira R.·Ferron, Thomas J.·Mettry-Yassa, Magi·Hammons, Joshua A.·Jayathilake, Buddhinie·Molinero, Valeria·Karnes, John J.·Oakdale, James S.
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Abstract

Anion exchange membranes (AEMs) offer a cost-effective alternative to proton exchange membranes as alkaline fuel cells and electrolyzers permit the use of non-platinum group electrodes and components. Despite continued progress, the operational lifetime and stability of these membranes limit the widespread adoption of AEM-based electrochemical technologies. This study presents a flexible and easily implemented ultraviolet (UV)-initiated nitrene-based cross-linking method which uses a small, facile organic azide precursor. As a proof of concept, we demonstrate this approach on the well-studied poly(2,6-dimethyl-1,4-phenylene oxide) quaternary ammonium AEM (QPPO) polyelectrolyte. Further, a survey of cross-linker density (2.5–10 mol %) found that the addition of 10 mol % results in a 59% reduction in water uptake, a 58.8% decrease in the swell ratio, and a 31% increase in tensile strength vs the un-cross-linked material. Nitrene cross-linking also enhanced the membrane’s durability, enabling 1000 h of stable performance under electrochemical load. This UV-initiated cross-linking method may be easily integrated into production processes, allowing chemical cross-linking at any stage, including posthydration.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYDegradationElectrical conductivityMembranesNucleic acid structureTesting and assessment

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Clemens, Auston L., Cerón, Maira R., Ferron, Thomas J., Mettry-Yassa, Magi, Hammons, Joshua A., Jayathilake, Buddhinie, Molinero, Valeria, Karnes, John J., Oakdale, James S.. 2024-04-12. Ultraviolet-Activated Solid-State Nitrene Cross-Linking: A Scalable Pathway to Prolonged Lifespan in Anion Exchange Membranes. https://doi.org/10.1021/acsapm.3c02885

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