dc.contributor.author
Reith, Lukas
dc.contributor.author
Hausmann, Jan Niklas
dc.contributor.author
Mebs, Stefan
dc.contributor.author
Mondal, Indranil
dc.contributor.author
Dau, Holger
dc.contributor.author
Driess, Matthias
dc.contributor.author
Menezes, Prashanth W.
dc.date.accessioned
2023-04-21T06:29:57Z
dc.date.available
2023-04-21T06:29:57Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/39031
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-38747
dc.description.abstract
Cobalt‐iron oxyhydroxides (CoFeOOHx) are among the most active catalysts for the oxygen evolution reaction (OER). However, their redox behavior and the electronic and chemical structure of their active sites are still ambiguous. To shed more light on this, the complete and rapid reconstruction of four helical cobalt‐iron borophosphates with different Co:Fe ratios into disordered cobalt‐iron oxyhydroxides can be achieved, which are electrolyte‐penetrable and thus most transition metal sites can potentially participate in the OER. To track the redox behavior and to identify the active structure, quasi in situ X‐ray absorption spectroscopy is applied. Iron in high oxidation states ≥ IV (Fe4+) and its substantial redox behavior with an average oxidation state of around 2.8 to above 3.2 is detected. Furthermore, a 6% contraction of the Fe‐O bond length compared to Fe3+OOH references is observed during OER and a strong distortion of the [MO6] octahedra is identified. It is hypothesized that this bond contraction is caused by the presence of oxyl radicals and that di‐µ‐oxyl radical bridged cobalt‐iron centers are the active sites. It is anticipated that the detailed electronic and structural description can substantially contribute to the debate on the nature of the active site in bimetallic iron‐containing OER catalysts.
en
dc.format.extent
11 Seiten
dc.rights
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
bimetallic electrocatalysts
en
dc.subject
in situ spectroscopy
en
dc.subject
layered double hydroxides
en
dc.subject
precatalysts
en
dc.subject
redox noninnocent oxo ions
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
dc.title
In Situ Detection of Iron in Oxidation States ≥ IV in Cobalt‐Iron Oxyhydroxide Reconstructed during Oxygen Evolution Reaction
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.articlenumber
2203886
dcterms.bibliographicCitation.doi
10.1002/aenm.202203886
dcterms.bibliographicCitation.journaltitle
Advanced Energy Materials
dcterms.bibliographicCitation.number
12
dcterms.bibliographicCitation.volume
13
dcterms.bibliographicCitation.url
https://doi.org/10.1002/aenm.202203886
refubium.affiliation
Physik
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
1614-6840
refubium.resourceType.provider
DeepGreen