Nafion 117 stability under conditions of PEM water electrolysis at elevated temperature and pressure

• Published in: International journal of hydrogen energy 2016-01, Vol.41 (4), p.2177-2188
• Main Authors: Mališ, Jakub, Mazúr, Petr, Paidar, Martin, Bystron, Tomas, Bouzek, Karel
• Format: Article
• Language: English
• Subjects: Degradation; Electrolysis; Electrolytic cells; Elevated pressure; Elevated temperature; High temperature; Hydrogen-based energy; Ionic conductivity; Membranes; Nafion 117; Spectra; Stability
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2015.11.102

In this work a systematic study of the behaviour of a Nafion 117 membrane under conditions of elevated temperatures (up to 150 °C) and pressure (up to 0.7 MPa) was carried out. Attention focused primarily on the ionic conductivity of the membrane in the proton form with exposure to the conditions under study for up to 800 h. The ion-exchange capacity, morphology, FTIR and NMR spectra of the membrane were determined to explain the decline in conductivity observed over time. The techniques used did not reveal any chemical degradation of the membrane polymer. The morphological changes to the membrane connected with excessive expansion of the internal structure of the polymer are assumed to be the reason for the phenomenon observed. Finally, to confirm the conclusions derived, the membrane behaviour in a laboratory-scale water electrolysis cell was studied under operating conditions corresponding to its prior characterization. •Nafion®117 conductivity at temperature up to 150 °C and pressure up to 0.7 MPa.•Elevated temperature and pressure impact on the Nafion®117 chemical stability.•Relation between the membrane conductivity and volumetric expansion.•Nafion®117 membrane stability in water electrolysis at elevated temperature.