Gast ::
| Hauptseite > Publikationsdatenbank > Degradation studies of a short-side-chained PFSA material for industrial water electrolysis by MAS and PFG-NMR |
| Hauptseite > Publikationsdatenbank > Degradation studies of a short-side-chained PFSA material for industrial water electrolysis by MAS and PFG-NMR |
| Poster (Other) | FZJ-2024-05346 |
; ; ; ; ;
2024
This record in other databases:
Please use a persistent id in citations: doi:10.34734/FZJ-2024-05346
Abstract: Proton exchange membrane (PEM) electrolysis is considered as a promising technique to produce green hydrogen at high purity. Although PEM can be operated in an electrolysis cell at high energy efficiency, this method has not yet been implemented on a large scale in the chemical industry. Additional to the insufficient lifetime and high cost of the components a ban of per- and polyfluoroalkyl substances is being discussed. This forces energy companies to use PEMs efficiently, for which reason the industry is in search of ways to recycle the membrane material. In various studies on this topic, the recycling process is based on the use of alcohols to separate the catalyst material from the PEM, but the influence of the separation mechanism on the structure of the PEM is little discussed. A screening routine to detect alteration of the performance and molecular structure of PEMs is presented and demonstrated on a short side-chain perfluorosulfonic acid ionomer. 1H PFG NMR measurements revealed that the proton diffusion performance is significantly altered by the separation process while at the same time, two instead of one diffusion coefficients were observed. This shows that even simple measurements provide sufficient contrast to qualitatively estimate the invasiveness of a separation technique, which offers an efficient method for industrial quality control. Additionally, it was possible to identify the nature of degradation from relative intensity changes of different functional groups in the material, as 19F MAS NMR spectra are highly sensitive to chemical alteration. The 19F T1 relaxation times were also significantly altered by hydration and the separation mechanism, suggesting a change in the spatial structure of the PEM. Therefore, this work is of particular interest for industry, as it presents methods that provide clear indicators for assessing the quality of PEMs and quantitative indicators for further assessing degradation processes.
Keyword(s): Energy (1st) ; Chemistry (2nd)
|
The record appears in these collections: |
PDF