Anode Catalysts in Anion-Exchange-Membrane Electrolysis without Supporting Electrolyte Conductivity, Dynamics, and Ionomer Degradation

Anode Catalysts in Anion-Exchange-Membrane Electrolysis without Supporting Electrolyte : Conductivity, Dynamics, and Ionomer Degradation

© 2022 Wiley-VCH GmbH.

Bibliographische Detailangaben
Veröffentlicht in:Advanced materials (Deerfield Beach, Fla.). - 1998. - 34(2022), 35 vom: 01. Sept., Seite e2203033
1. Verfasser: Krivina, Raina A (VerfasserIn)
Weitere Verfasser: Lindquist, Grace A, Beaudoin, Sarah R, Stovall, Timothy Nathan, Thompson, Willow L, Twight, Liam P, Marsh, Douglas, Grzyb, Joseph, Fabrizio, Kevin, Hutchison, James E, Boettcher, Shannon W
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2022
Zugriff auf das übergeordnete Werk:Advanced materials (Deerfield Beach, Fla.)
Schlagworte:Journal Article alkaline water electrolysis anion-exchange membranes membrane electrolysis non-platinum-group-metal catalysts oxygen evolution catalysis
Beschreibung
Zusammenfassung:© 2022 Wiley-VCH GmbH.
Anion-exchange-membrane water electrolyzers (AEMWEs) in principle operate without soluble electrolyte using earth-abundant catalysts and cell materials and thus lower the cost of green H2 . Current systems lack competitive performance and the durability needed for commercialization. One critical issue is a poor understanding of catalyst-specific degradation processes in the electrolyzer. While non-platinum-group-metal (non-PGM) oxygen-evolution catalysts show excellent performance and durability in strongly alkaline electrolyte, this has not transferred directly to pure-water AEMWEs. Here, AEMWEs with five non-PGM anode catalysts are built and the catalysts' structural stability and interactions with the alkaline ionomer are characterized during electrolyzer operation and post-mortem. The results show catalyst electrical conductivity is one key to obtaining high-performing systems and that many non-PGM catalysts restructure during operation. Dynamic Fe sites correlate with enhanced degradation rates, as does the addition of soluble Fe impurities. In contrast, electronically conductive Co3 O4 nanoparticles (without Fe in the crystal structure) yield AEMWEs from simple, standard preparation methods, with performance and stability comparable to IrO2 . These results reveal the fundamental dynamic catalytic processes resulting in AEMWE device failure under relevant conditions, demonstrate a viable non-PGM catalyst for AEMWE operation, and illustrate underlying design rules for engineering anode catalyst/ionomer layers with higher performance and durability
Beschreibung:Date Revised 07.09.2022
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1521-4095
DOI:10.1002/adma.202203033