A comparative study of proton exchange membranes: performance, stability and hydrogen crossover

Pitman, Alex (2024) A comparative study of proton exchange membranes: performance, stability and hydrogen crossover. MRes thesis, University of Glasgow.

Abstract

Proton exchange membrane water electrolysis (PEMWE) presents itself as an attractive tool to support the renewable energy transition. By coupling these technologies together, a clean and environmentally friendly route to hydrogen production is created. Hydrogen can then act as an energy vector, delivering power areas where it is needed most. At the heart of the technology lies the proton exchange membrane (PEM) – a polymer that acts as a solid electrolyte, thus allowing protons to permeate through the device. The benchmark membrane is the Nafion™ brand, which has backbone similar to polytetrafluoroethylene (PTFE) and a long fluorinated carbon side chain capped with sulfonic groups. Aquivion® is another brand of membrane – similar to Nafion™, only that the side chain is shorter in length. Despite these membranes competing in identical markets, there are few existing comparative studies regarding their use in water electrolysis. The data that is available suggests the short side chain of Aquivion® yields optimal properties. Unfortunately, in recent months both of these membranes have been discontinued by many leading retailers, leaving researchers with no tried and tested membrane available for use.

This project investigated both of these issues. Aquivion® and Nafion™ were evaluated across three key parameters – performance, degradation rate and hydrogen crossover - and compared against an unbranded commercially available membrane. The results showed that the use of a short side chain membrane did not significantly vary device operation across the three key parameters, and also showed the unbranded membrane to perform at levels similar to the branded membranes. Ex-situ characterisation revealed the presence of membrane degradation after device operation. Future experiments could see the unbranded membrane being tested at timescales required in an industrial electrolyser.

• Item Type: Thesis (MRes)
• Qualification Level: Masters
• Subjects: Q Science > QD Chemistry
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Symes, Professor Mark, Moiras, Professor Charalampos and Faqeeh, Mr. Abdulhai
• Date of Award: 2024
• Depositing User: Theses Team
• Unique ID: glathesis:2024-84729
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 02 Dec 2024 15:02
• Last Modified: 02 Dec 2024 15:09
• Thesis DOI: 10.5525/gla.thesis.84729
• URI: https://theses.gla.ac.uk/id/eprint/84729