Physikalische Chemie - Direktor: Prof. Dr. Martin Wolf
Department Seminar
Host: Akitoshi Shiotari

Monday, April 17, 2023, 11:00 am
All are invited to meet around 10:40 am for a chat with coffee & cookies.
PC Seminar Room, G 2.06, Faradayweg 4
Aji Alexander
Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
Perovskites as Supports for Single-atom Catalysis
Perovskite surfaces attract attention in the catalysis community due to these materials’ promising chemical properties, good ability to separate electron-hole pairs in light harvesting, and the presence of ferroelectricity in many perovskites. While perovskites possess a unique set of interesting bulk properties, their surfaces are much less understood; the main open questions are their structural stability and associated chemical reactivity and catalytic selectivity.
My talk will focus on the local structure of doped KTaO3(001)  and SrTiO3(001) surfaces and modifying their catalytic activity by extrinsic metals, with the main focus on cobalt. I will demonstrate the implementation of combined STM/AFM measurement along with XPS data to show the thermally assisted stability achievement and the tendency of the guest atoms to disperse in the form of single adatoms on the polarly uncompensated KTaO3(001) [1] and SrTiO3(001) surfaces. The interaction of cobalt with surfaces under various reducing and oxidizing conditions, as well as a function of temperature, will be highlighted. This sheds light on how cobalt's metallic, oxide, and hydroxide phases vary depending on the environment.

[1] M. Setvin, M. Reticcioli, F. Poelzleitner et al., Science 359, 572 (2018)