03. December 2024, 16:00 until 17:00

Matthias Kogler TU Wien, IAP, FB Angewandte Grenzflächenphysik

Seminar

Bulk-independent surface oxide composition controls the electrochemical performance of high-entropy alloys

Multi-element alloys and high-entropy alloys show promising electrocatalytic behavior for water splitting and other catalytic reactions, due to their highly tunable composition. While preparation and synthesis of these materials are thoroughly investigated, the true reactive surface composition is still not well understood, as it may significantly differ from the bulk composition. Precise knowledge and understanding of resulting surface composition is crucial for effective control of the electrocatalytic performance. In this work, low energy ion scattering spectroscopy was applied to determine the surface oxide composition of a series of Ni-based multi- metallic alloys with Mn, Fe, Co, and Cr under alkaline, neutral and acidic conditions. The composition of the surface oxide was investigated with sub-nanometer depth resolution. In electrochemical tests, good catalytic activity was found for the oxygen evolution reaction, although a strong dependence on the selected reaction conditions was observed. The surface composition under OER conditions deviates significantly from the bulk composition. No significant benefit of high entropy alloying compared with binary or ternary alloys concerning catalytic OER performance was found.

Calendar entry

Event location

SEM.R. DB gelb 05 B
1040 Wien
Wiedner Hauptstraße 8-10/E134

 

Organiser

IAP
Manuela Marik
marik@iap.tuwien.ac.at

 

Public

Yes

 

Entrance fee

No

 

Registration required

No

Past events can be found in the  archive.

Internal users can find the list of upcoming seminar presentations and the seminar dates to be booked in the E134 Colab Space., opens an external URL in a new window