21-30 September 2021
Online Conference
Europe/Berlin timezone

Operando x-ray spectroscopy studies of mesoporous FeNiOx catalysts for alkaline water splitting

21 Sep 2021, 17:05
20m
Online Conference

Online Conference

CYSS2021 will be hosted online using Zoom. The poster session will follow a dual-format approach using a chat-platform and videoconference rooms.
Plenary Talk Spectroscopy Spectroscopy I

Speaker

Hanna Trzesniowski (Helmholtz-Zentrum Berlin für Materialien und Energie)

Description

A carrier of renewable energy that will play a key role in the replacement of fossil fuels is molecular hydrogen, which can be generated by electrocatalytic water splitting. The anodic reaction of the water electrolysis process, the oxygen evolution reaction (OER) limits the overall efficiency of water electrolysis due to high overpotentials.[1] Thus to enable the large-scale production of hydrogen, suitable electrocatalysts are required.
In search for cost-effective, abundant and stable electro-catalytic materials for OER, transition metal oxides have been found to be promising candidates in alkaline solutions.[2]
An in-depth understanding of the behavior of the involved electrocatalytic materials under reaction conditions is crucial for the development of efficient and stable electrocatalysts for water splitting. Operando x-ray spectroscopy enables the observation of the electronic structure of the catalyst under electrocatalytic reaction conditions and provides insight into processes occurring at the electrode/electrolyte interface.
We propose mesoporous FeNiOx films as model systems for the spectroscopic investigation of the electrode/electrolyte interface under alkaline OER conditions. Their exceptionally high porosity and their film thickness of about 100 nm make these nanostructured systems ideal to track their electronic structure during catalytic cycles via synchrotron-radiation based soft x-ray spectroscopy methods, such as x-ray absorption spectroscopy (XAS) in total electron yield (TEY) and total fluorescence yield (TFY) mode. To perform operando XAS, we use a flow-cell design pioneered by the Schlögl group at the Fritz Haber Institute Berlin (Tesch, Bonke) [3]) which allows us to study the electrode/electrolyte interface at a defined potential.

References
[1] N. T. Suen, S. F. Hung, Q. Quan, N. Zhang, Y. J. Xu, and H. M. Chen, Chem. Soc. Rev., vol. 46, no. 2, pp. 337–365, 2017, doi: 10.1039/c6cs00328a.
[2] B. M. Hunter, H. B. Gray, and A. M. Müller, Chem. Rev., vol. 116, no. 22, pp. 14120–14136, 2016, doi: 10.1021/acs.chemrev.6b00398.
[3] M. F. Tesch et al., Angew. Chemie - Int. Ed., vol. 58, no. 11, pp. 3426–3432, 2019, doi: 10.1002/anie.201810825.

Primary author

Hanna Trzesniowski (Helmholtz-Zentrum Berlin für Materialien und Energie)

Co-authors

Dr Ronny Golnak (Helmholtz-Zentrum Berlin für Materialien und Energie) Dennis Hein (Helmholtz-Zentrum Berlin für Materialien und Energie) Garlef Wartner (Helmholtz-Zentrum Berlin für Materialien und Energie) Aleks Arinchtein (Technische Universität Berlin) Dr Robert Seidel (Helmholtz-Zentrum Berlin für Materialien und Energie) Dr Ralph Kraehnert (Technische Universität Berlin)

Presentation Materials