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Highly quaternized polystyrene ionomers for high performance anion exchange membrane water electrolysers


Alkaline anion exchange membrane (AEM) electrolysers to produce hydrogen from water are still at an early stage of development, and their performance is far lower than that of systems based on proton exchange membranes. Here, we report an ammonium-enriched anion exchange ionomer that improves the performance of an AEM electrolyser to levels approaching that of state-of-the-art proton exchange membrane electrolysers. Using rotating-disk electrode experiments, we show that a high pH (>13) in the electrode binder is the critical factor for improving the activity of the hydrogen- and oxygen-evolution reactions in AEM electrolysers. Based on this observation, we prepared and tested several quaternized polystyrene electrode binders in an AEM electrolyser. Using the binder with the highest ionic concentration and a NiFe oxygen evolution catalyst, we demonstrated performance of 2.7 A cm−2 at 1.8 V without a corrosive circulating alkaline solution. The limited durability of the AEM electrolyser remains a challenge to be addressed in the future.

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Fig. 1: Schematic of low-temperature water electrolysis cells.
Fig. 2: Impact of NaOH concentration on activities of electrocatalysts.
Fig. 3: The chemical structure of the polymeric materials used for the study.
Fig. 4: Impact of ionomer on AEM performance.
Fig. 5: AEM electrolyser performance catalysed by a PGM-free anode.
Fig. 6: Durability of AEM electrolysers catalysed by NiFe anodes.

Data availability

The authors declare that the data supporting the findings of this study are available within the paper, Supplementary Information and Source Data files. Further data beyond the immediate results presented here are available from the corresponding authors upon reasonable request.


  1. 1.

    Abbasi, R. et al. A roadmap to low-cost hydrogen with hydroxide exchange membrane electrolyzers. Adv. Mater. 31, 1805876 (2019).

    Google Scholar 

  2. 2.

    Vincent, I. & Bessarabov, D. Low cost hydrogen production by anion exchange membrane electrolysis: a review. Renew. Sustain. Energy Rev. 81, 1690–1704 (2018).

    Google Scholar 

  3. 3.

    Buttler, A. & Spliethoff, H. Current status of water electrolysis for energy storage, grid balancing and sector coupling via power-to-gas and power-to-liquids: a review. Renew. Sustain. Energy Rev. 82, 2440–2454 (2018).

    Google Scholar 

  4. 4.

    Seh, Z. W. et al. Combining theory and experiment in electrocatalysis: insights into matrials design. Science 355, eaad4998 (2017).

    Google Scholar 

  5. 5.

    Zeng, K. & Zhang, D. K. Recent progress in alkaline water electrolysis for hydrogen production and applications. Prog. Energy Combust. Sci. 36, 307–326 (2010).

    Google Scholar 

  6. 6.

    Schmidt, O. et al. Future cost and performance of water electrolysis: an expert elicitation study. Int. J. Hydrog. Energy 42, 30470–30492 (2017).

    Google Scholar 

  7. 7.

    Gulzow, E. & Schulze, M. Long-term operation of AFC electrodes with CO2 containing gases. J. Power Sources 127, 243–251 (2004).

    Google Scholar 

  8. 8.

    Gulzow, E. Alkaline fuel cells: a critical view. J. Power Sources 61, 99–104 (1996).

    Google Scholar 

  9. 9.

    Naughton, M. S., Brushett, F. R. & Kenis, P. J. A. Carbonate resilience of flowing electrolyte-based alkaline fuel cells. J. Power Sources 196, 1762–1768 (2011).

    Google Scholar 

  10. 10.

    Bernt, M. & Gasteiger, H. A. Influence of ionomer content in IrO2/TiO2 electrodes on PEM water electrolyzer performance. J. Electrochem. Soc. 163, F3179–F3189 (2016).

    Google Scholar 

  11. 11.

    Lewinski, K. A., van der Vliet, D. F. & Luopa, S. M. NSTF advances for PEM electrolysis—the effect of alloying on activity of NSTF electrolyzer catalysts and performance of NSTF based PEM electrolyzers. ECS Trans. 69, 893–917 (2015).

    Google Scholar 

  12. 12.

    Babic, U., Suermann, M., Buehi, F. N., Gubler, L. & Schmidt, T. J. Review-identifying critical gaps for polymer electrolyte water electrolysis development. J. Electrochem. Soc. 164, F387–F399 (2017).

    Google Scholar 

  13. 13.

    Li, H. et al. Effects of operating conditions on performance of high-temperature polymer electrolyte water electrolyzer. J. Power Sources 318, 192–199 (2016).

    Google Scholar 

  14. 14.

    Barbir, F. PEM electrolysis for production of hydrogen from renewable energy sources. Sol. Energy 78, 661–669 (2005).

    Google Scholar 

  15. 15.

    Ayers, K. E. et al. Characterization of anion exchange membrane technology for low cost electrolysis. ECS Trans. 45, 121–130 (2013).

    Google Scholar 

  16. 16.

    Hickner, M. A., Herring, A. M. & Coughlin, E. B. Anion exchange membranes: current status and moving forward. J. Polym. Sci. Pol. Phys. 51, 1727–1735 (2013).

    Google Scholar 

  17. 17.

    Varcoe, J. R. et al. Anion-exchange membranes in electrochemical energy systems. Energy Environ. Sci. 7, 3135–3191 (2014).

    Google Scholar 

  18. 18.

    Park, E. J. & Kim, Y. S. Quaternized aryl ether-free polyaromatics for alkaline membrane fuel cells: synthesis, properties, and performance—a topical review. J. Mater. Chem. A 6, 15456–15477 (2018).

    Google Scholar 

  19. 19.

    Niether, C. et al. Improved water electrolysis using magnetic heating of FeC–Ni core–shell nanoparticles. Nat. Energy 3, 476–483 (2018).

    Google Scholar 

  20. 20.

    Suntivich, J., May, K. J., Gasteiger, H. A., Goodenough, J. B. & Shao-Horn, Y. A perovskite oxide optimized for oxygen evolution catalysis from molecular orbital principles. Science 334, 1383–1385 (2011).

    Google Scholar 

  21. 21.

    Zhao, S. L. et al. Ultrathin metal–organic framework nanosheets for electrocatalytic oxygen evolution. Nat. Energy 1, 16184 (2016).

    Google Scholar 

  22. 22.

    Kaczur, J. J., Yang, H. Z., Liu, Z. C., Sajjad, S. A. & Masel, R. I. Carbon dioxide and water electrolysis using new alkaline stable anion membranes. Front. Chem. 6, 263 (2018).

    Google Scholar 

  23. 23.

    Kraglund, M. R. et al. Ion-solvating membranes as a new approach towards high rate alkaline electrolyzers. Energy Environ. Sci. 12, 3313–3318 (2019).

    Google Scholar 

  24. 24.

    Leng, Y. J. et al. Solid-state water electrolysis with an alkaline membrane. J. Am. Chem. Soc. 134, 9054–9057 (2012).

    Google Scholar 

  25. 25.

    Parrondo, J. et al. Degradation of anion exchange membranes used for hydrogen production by ultrapure water electrolysis. RSC Adv. 4, 9875–9879 (2014).

    Google Scholar 

  26. 26.

    Pandiarajan, T., Berchmans, L. J. & Ravichandran, S. Fabrication of spinel ferrite based alkaline anion exchange membrane water electrolysers for hydrogen production. RSC Adv. 5, 34100–34108 (2015).

    Google Scholar 

  27. 27.

    Xiao, L. et al. First implementation of alkaline polymer electrolyte water electrolysis working only with pure water. Energy Environ. Sci. 5, 7869–7871 (2012).

    Google Scholar 

  28. 28.

    Fan et al. Poly(bis-arylimidazoliums) possessing high hydroxide ion exchange capacity and high alkaline stability. Nat. Comm. 10, 2306 (2019).

    Google Scholar 

  29. 29.

    Omasta, T. J. et al. Beyond catalysis and membranes: visualizing and solving the challenge of electrode water accumulation and flooding in AEMFCs. Energy Environ. Sci. 11, 551–558 (2018).

    Google Scholar 

  30. 30.

    Maurya, S. et al. Rational design of polyaromatic ionomers for alkaline membrane fuel cells with >1 W cm–2 power density. Energy Environ. Sci. 11, 3283–3291 (2018).

    Google Scholar 

  31. 31.

    Wang, J. et al. Poly(aryl piperidinium) membranes and ionomers for hydroxide exchange membrane fuel cells. Nat. Energy 4, 392–398 (2019).

    Google Scholar 

  32. 32.

    Huang, G. et al. Composite poly(norbornene) anion conducting membrnaes for achieving durability, water management and high power (3.4 W/cm2) in hydrogen/oxygen alkaline fuel cells. J. Electrochem. Soc. 166, F637–F644 (2019).

    Google Scholar 

  33. 33.

    Chung, H. T., Martinez, U., Chlistunoff, J., Matanovic, I. & Kim, Y. S. Cation-hydroxide-water co-adsorption inhibits the alkaline hydrogen oxidation reaction. J. Phys. Chem. Lett. 7, 4464–4469 (2016).

    Google Scholar 

  34. 34.

    Dumont, J. H. et al. Unusally high concentration of alkyl ammonium hydroxide in the cation-dydroxide-water coadsorbed layer on Pt. ACS Appl. Mater. Interfaces 12, 1825–1831 (2020).

    Google Scholar 

  35. 35.

    Trzesniewski, B. J. et al. In situ observation of active oxygen species in Fe-containing Ni-based oxygen evolution catalysts: the effect of pH on electrochemical activity. J. Am. Chem. Soc. 137, 15112–15121 (2015).

    Google Scholar 

  36. 36.

    Kraglund, M. R. et al. Zero-gap alkaline water electrolysis using ion-solvating polymer electrolyte membranes at reduced KOH concentrations. J. Electrochem. Soc. 163, F3125–F3131 (2016).

    Google Scholar 

  37. 37.

    Li, D. et al. Phenyl oxidation impacts the durability of alkaline membrane water electrolyzer. ACS Appl. Mater. Interfaces 11, 9696–9701 (2019).

    Google Scholar 

  38. 38.

    Matanovic, I. et al. Adsorption of polyaromatic backbone impacts the performance of anion exchange membrane fuel cells. Chem. Mater. 31, 4195–4204 (2019).

    Google Scholar 

  39. 39.

    Maurya, S., Fujimoto, C. H., Hibbs, M. R., Villarrubia, C. N. & Kim, Y. S. Toward improved alkaline membrane fuel cell performance using quaternized aryl-ether free polyaromatics. Chem. Mater. 30, 2188–2192 (2018).

    Google Scholar 

  40. 40.

    Li, D., Chung, H. T., Maurya, S., Matanovic, I. & Kim, Y. S. Impact of ionomer adsorption on alkaline hydrogen oxidation activity and fuel cell performance. Curr. Opin. Electrochem. 12, 189–195 (2018).

    Google Scholar 

  41. 41.

    Poynton, S. D. et al. Preparation of radiation-grafted powders for use as anion exchange ionomers in alkaline polymer electrolyte fuel cells. J. Mater. Chem. A 2, 5124–5130 (2014).

    Google Scholar 

  42. 42.

    Jeon, J. Y. et al. Synthesis of aromatic anion exchange membranes by Friedel-Crafts bromoalkylation and cross-linking of polystyrene block copolymers. Macromolecules 52, 2139–2147 (2019).

    Google Scholar 

  43. 43.

    Lee, W. H., Kim, Y. S. & Bae, C. Robust hydroxide ion conducting poly(biphenyl alkylene)s for alkaline fuel cell membranes. ACS Macro Lett. 4, 814–818 (2015).

    Google Scholar 

  44. 44.

    Zhu, L., Yu, X. D. & Hickner, M. A. Exploring backbone-cation alkyl spacers for multi-cation side chain anion exchange membranes. J. Power Sources 375, 433–441 (2018).

    Google Scholar 

  45. 45.

    Wang, J. H. et al. Structure-property relationships in hydroxide-exchange membranes with cation strings and high ion-exchange capacity. ChemSusChem 8, 4229–4234 (2015).

    Google Scholar 

  46. 46.

    Hibbs, M. R. Alkaline stability of poly(phenylene)-based anion exchange membranes with various cations. J. Polym. Sci. B Polym. Phys. 51, 1736–1742 (2013).

    Google Scholar 

  47. 47.

    Park, E. J. et al. Alkaline stability of quaternized Diels-Alder polyphenylenes. Macromolecules 52, 5419–5428 (2019).

    Google Scholar 

  48. 48.

    Choe, Y. K. et al. Alkaline stability of benzyl trimethyl ammonium functionalized polyaromatics: a computational and experimental study. Chem. Mater. 26, 5675–5682 (2014).

    Google Scholar 

  49. 49.

    Fu, S. F. et al. Ultrafine and highly disordered Ni2Fe1 nanofoams enabled highly efficient oxygen evolution reaction in alkaline electrolyte. Nano Energy 44, 319–326 (2018).

    Google Scholar 

  50. 50.

    Kabir, S. et al. Platinum group metal-free NiMo hydrogen oxidation catalysts: high performance and durability in alkaline exchange membrane fuel cells. J. Mater. Chem. A 5, 24433–24443 (2017).

    Google Scholar 

  51. 51.

    Lee, K.-S., Spendelow, J. S., Choe, Y.-K., Fujimoto, C. & Kim, Y. S. An operationally flexible fuel cell based on quaternary ammonium–biphosphate ion pairs. Nat. Energy 1, 16120 (2016).

    Google Scholar 

  52. 52.

    Gao, H., Li, J. & Lian, K. Alkaline quaternary ammonium hydroxides and their polymer electrolytes for electrochemical capacitors. RSC Adv. 4, 21332–21339 (2014).

    Google Scholar 

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We gratefully acknowledge research support from the HydroGEN Advanced Water Splitting Materials Consortium, established as part of the Energy Materials Network under the US Department of Energy, Office of Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office (program manager: D. Peterson). Los Alamos National Laboratory is operated by Triad National Security under the US Department of Energy, under contract no. 89233218CNA000001. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, a wholly owned subsidiary of Honeywell International, for the US Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. Y.L. acknowledges research support from the JCDREAM. We thank A. Dattelbaum for constructive criticism of the manuscript.

Author information




Y.S.K. designed the experiments. D.L. carried out the electrochemical analysis and electrolyser test. E.J.P., E.D.B and C.F. synthesized the polymeric materials. W.Z., Q.S., Y.Z., H.T. and Y.L. synthesized and characterized the NiFe catalysts. A.S. and B.Z. synthesized and characterized the NiMo/C catalysts. D.L., E.J.P., W.Z., Y.L., A.S. and Y.S.K. contributed to writing the article. Y.S.K. initiated the collaborative project. Y.L., B.Z. and Y.S.K. supervised and guided the work.

Corresponding authors

Correspondence to Yuehe Lin or Yu Seung Kim.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–12, Tables 1–2 and refs. 1–2.

Source data

Source Data Fig. 2

Electrochemical data for plotting.

Source Data Fig. 4

Electrochemical data for plotting.

Source Data Fig. 5

Electrochemical data for plotting.

Source Data Fig. 6

Electrochemical data for plotting.

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Li, D., Park, E.J., Zhu, W. et al. Highly quaternized polystyrene ionomers for high performance anion exchange membrane water electrolysers. Nat Energy 5, 378–385 (2020).

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