Tailoring high-performance catalyst architectures via ‘accessional ionomer coatings’ for anion exchange membrane water electrolysis

• Published in: International journal of hydrogen energy Vol. 49; pp. 591 - 603
• Main Authors: Lou, Kaiyue, Xia, Lu, Friedrich, Jochen, Shviro, Meital
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 02.01.2024
• Subjects: Alkaline water electrolysis; Anion exchange membrane; Electrode architecture; Ionomer layer; MEA manufacturing; Alkaline water electrolysis; MEA manufacturing; Electrode architecture; Anion exchange membrane; Ionomer layer
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.08.281

Anion exchange membrane water electrolysis (AEMWE) represents a viable solution for achieving large-scale, low-cost hydrogen production. The catalyst and ionomer layers play a crucial role in facilitating the electrochemical reactions on the electrodes in AEMWE. However, the optimization of catalyst-ionomer configurations through architectural and structural development remains an understudied area of research, despite its critical importance. Here, this study involved the preparation and investigation of multiple catalyst-ionomer configurations, including those with single and dual ionomer layers at both the cathode and anode. Our findings indicate that incorporating an additional ionomer layer in the catalyst-coated membrane-based membrane electrode assemblies (MEAs) improve their performance by enhancing interfacial contact area and facilitating charge transfer, compared to MEA configurations without ionomer layers. While ionomer-modified catalyst-coated substrate-based MEA configurations do not show a significant improvement in activity, they demonstrate lower potentials during a 150-h stability test. Furthermore, cost-effective MEAs are fabricated by replacing noble metal anode catalysts with commercially available NiFe nanoparticles, which exhibit comparable catalytic activity and enhanced durability. •Introduction of ionomer interlayers into the MEA of an alkaline water electrolyzer.•Ionomer interlayer improves the cell performance of CCM-based configurations due to enlarged ECSA.•Ionomer-modified CCS exhibit reduced overpotential and degradation in 150 h operation.•Innovative hybrid CCM-CCS configuration highlights cost-effective NiFe catalyst.