Investigating Cathode Ionomer Content and Assembly Techniques for Anion Exchange Membrane Water Electrolyzers

Title data

Titheridge, Laura J. ; Sharma, Shailendra ; Soisson, Anouk ; Tiffin, Campbell ; Roth, Christina ; Marshall, Aaron Timothy:
Investigating Cathode Ionomer Content and Assembly Techniques for Anion Exchange Membrane Water Electrolyzers.
In: ACS Electrochemistry. (2025) .
ISSN 2997-0571
DOI: https://doi.org/10.1021/acselectrochem.4c00225

Project information

Abstract in another language

Anion exchange membrane water electrolysis
(AEMWE) offers a promising solution for achieving large-scale,
low-cost hydrogen production. Optimizing cathode catalyst-
ionomer-membrane configurations is crucial for improving
AEMWE performance. Herein, cathodes using Pt/C and
Sustainion, PiperION, or Nafion with varying content (5−25 wt
%) and assembly techniques (catalyst-coated substrates, CCSs, and
catalyst-coated membranes, CCMs) are examined to reveal their
impact on AEMWE performance. Scanning electron microscopy
revealed Nafion produced the most homogeneous catalyst layers
and smallest particle sizes. In half-cell testing, 20 wt % Nafion
achieved the lowest overpotential of −15.6 mV at 10 mA cm−2 and
the highest electrochemical surface area of 83.71 cm2 mg−1Pt/C. The
performance trend in CCS was more pronounced than in CCM, as the catalyst layer is deposited layer-by-layer during CCM
fabrication and blocks active sites, obscuring any benefits of optimizing the ionomer loading to achieve minimal agglomeration and
homogeneity. Additionally, CCS outperformed CCM, achieving lower ohmic and charge transfer resistances. The ideal ionomer
content was 15−20 wt % throughout all samples, with 20 wt % Nafion achieving the best performance, owing to the low charge
transfer resistance.