Available at: https://digitalcommons.calpoly.edu/theses/3125
Date of Award
3-2025
Degree Name
MS in Polymers and Coatings
Department/Program
Chemistry & Biochemistry
College
College of Science and Mathematics
Advisor
Erik Sapper
Advisor Department
Chemistry & Biochemistry
Advisor College
College of Science and Mathematics
Abstract
The development of sustainably produced hydrogen fuel (“green hydrogen”) is key for the transition to clean energy sources. Green hydrogen is produced via water electrolysis. As with many clean energy sources, one of the major barriers for scaling water electrolysis is cost. A newer category of water electrolysis is Anionic Exchange Membrane (AEM) water electrolysis. AEM electrolysis systems have the potential to cost less as they do not require the expensive precious metal catalysts the current high preforming Proton Exchange Membrane water electrolysis technologies do. However, AEM lifetimes must be long enough to be cost competitive and AEM chemical durability is of question. This work focuses on the development of an ex-situ accelerated stress test (AST) protocol for AEMs that assesses the chemical durability. Hydroxide and radical attack were the dominant chemical degradation pathways identified in literature for AEMs. Furthermore, Hofmann elimination and nucleophilic substitution were identified as dominant hydroxide attack mechanisms. After iterating through experimental protocols, a final AST protocol was developed where both hydroxide and radical attack were observable through analysis of mol% composition, molecular weight, ionic conductivity, Areal Swell, and ultimate tensile strength. Hofmann elimination was observed, and multiple hydroxide attack mechanisms appear to be at play. This work enables others to quickly assess the chemical durability of different AEM chemistries & has the potential to help evaluate prototypes durability.
Included in
Membrane Science Commons, Polymer and Organic Materials Commons, Polymer Science Commons