TUdatalib : Role of Fe in the hydrogen oxidation reaction in a NiFe-based catalyst: An in situ Mössbauer spectroscopic investigation

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dc.contributor.advisor
dc.contributor.author	Ni, Lingmei, Elena S. Davydova, Ramesh K. Singh, Lubov Kolik-Shmuel, Dario R. Dekel, Ulrike I. Kramm1
dc.date.accessioned	2023-04-24T20:29:48Z
dc.date.available	2023-04-24T20:29:48Z
dc.date.issued	2023-04
dc.identifier.uri	https://tudatalib.ulb.tu-darmstadt.de/handle/tudatalib/3801
dc.identifier.uri	https://doi.org/10.48328/tudatalib-1129
dc.description	Nickel-based catalysts reach a high activity for the hydrogen oxidation reaction (HOR) in anion exchange membrane fuel cells. While incorporation of iron significantly decreases the HOR overpotential on NiFe-based catalysts, the reason for the enhanced activity remains only partially understood. For the first time, in situ 57Fe Mössbauer spectroscopy is used to gain insights into the iron-related composition at different potentials. The aim is to evaluate which changes occur on iron at potentials relevant for the HOR on the active Ni sites. It is found that different pre-conditionings at low potentials stabilize the iron at a low oxidation state as compared to the as-prepared catalyst powder. It is likely that the lower average oxidation state enables a higher exchange current density and a more efficient OH adsorption, which make the Volmer step much faster in the HOR. Insights from in situ Mössbauer spectroscopy enlighten the role of iron in the nickel-iron catalyst, paving the way for developing improved Ni-based catalysts for HOR catalysis.	de_DE
dc.language.iso	en	de_DE
dc.rights	Open Data Commons Attribution License (ODC-By) v1.0
dc.rights.uri	https://opendatacommons.org/licenses/by/1.0/
dc.subject.classification	322-02 Physikalische Chemie von Festkörpern und Oberflächen, Materialcharakterisierung	de_DE
dc.subject.ddc	540
dc.title	Role of Fe in the hydrogen oxidation reaction in a NiFe-based catalyst: An in situ Mössbauer spectroscopic investigation	de_DE
dc.type	Dataset	de_DE
tud.unit	TUDa