Perovskites as Supports for Single-atom Catalysis

PC Department Seminar
Date: Apr 17, 2023
Time: 11:00 AM (Local Time Germany)
Speaker: Aji Alexander
Charles University, Czech Republic
Location: Building G
Room: 2.06
Host: Akitoshi Shiotari

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)