Comparative Study of Anion Exchange Membranes for Application in Advanced AEM Water Electrolysers

The chemical nature of hydrogen combined with its capability to be an energy carrier for energy conversion devices with zero- emission and its higher energy density than any other commercial fossil fuel-based energy source, make it unique 1. The International Renewable Energy Agency has identified three of the most viable technologies for producing hydrogen in large volume, namely: alkaline water electrolyzers (AWEs), proton exchange membrane water electrolyzers (PEMWEs), and anion exchange membrane water electrolyzers (AEMWEs) 2. Among the three types of electrochemical devices the AEMWEs are the newest and most promising, because they (i) have the same slim design of the PEMWEs, (ii) can operate at high current densities, and (iii) can use non-precious catalysts 3. The durability and efficiency of the AEMWEs systems are significantly influenced by the anion exchange membranes (AEMs), which are currently under development. In addition, the used catalysts, as well as the methods for fabrication of the membrane electrode assemblies (MEAs) also impact substantially the electrolyzer’s performance. Catalyst-coated substrate (CCS) is one of the methods for fabrication of MEAs 4, while the other used method is known as catalyst coated membranes (CCMs). The Reactive Spray Deposition Technology (RSDT) is an innovative flame-assisted method that can be used for fabrication MEAs from both types 5. In this work, CCS are fabricated by the ultrasonic spray deposition method and 5 MEAs are assembled with various AEM membranes. This approach involves the application of Platinum Group Metal (PGM) catalysts, Pt/C and as cathode and anode catalyst layers, onto a Gas Diffusion Layer (C-GDL) and a porous transport layer (Ti-PTL). As fabricated CCSs are assembled with the three state-of-the-art commercially available AEMs, namely: FAA-3, Sustainion X-37, and TM1, and their performance is evaluated. In addition, CCSs with ultra-low PGM loadings in their catalyst layers are fabricated with the RSDT method and better performance in comparison to the baseline MEAs with high PGM loadings, is achieved. This comparative study provides valuable insights into the strengths and weaknesses of each membrane type for application in AEM water electrolysers. Reference: 1 M. G. Rasul, M. A. Hazrat, M. A. Sattar, M. I. Jahirul, and M. J. Shearer, “The future of hydrogen: Challenges on production, storage and applications,” Energy Conversion and Management , vol. 272, p. 116326, Nov. 2022, doi: 10.1016/j.enconman.2022.116326. 2 D. Yang et al. , “Patent analysis on green hydrogen technology for future promising technologies,” International Journal of Hydrogen Energy , vol. 48, no. 83, pp. 32241–32260, Oct. 2023, doi: 10.1016/j.ijhydene.2023.04.317. 3 D. S. Falcão, “Green Hydrogen Production by Anion Exchange Membrane Water Electrolysis: Status and Future Perspectives,” Energies , vol. 16, no. 2, p. 943, Jan. 2023, doi: 10.3390/en16020943. 4 J. E. Park et al. , “High-performance anion-exchange membrane water electrolysis,” Electrochimica Acta , vol. 295, pp. 99–106, Feb. 2019, doi: 10.1016/j.electacta.2018.10.143. 5 Z. Zeng, J. Xing, L. Bonville, D. R. Dekel, R. Maric, and S. Bliznakov, “Advanced nickel-based catalysts for the hydrogen oxidation reaction in alkaline media synthesized by reactive spray deposition technology: Study of the effect of particle size,” International Journal of Hydrogen Energy , p. S0360319923013721, Apr. 2023, doi: 10.1016/j.ijhydene.2023.03.249.