Sebastian Günther
In situ and in operando spectroscopy and microscopy of catalytic materials
We use surface analytical techniques for the in situ and in operando characterization of catalytic systems such as high temperature scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). XPS allows the analysis of samples under environmental conditions when sealing them with ultra-thin, electron transparent graphene membranes. For this purpose, we study the catalytic synthesis of monolayer graphene (ML-g) with control at the atomic level.
a) Grown ML-g flake on Cu imaged in optical microscopy.
b) Low energy electron diffraction pattern taken from ML-g/Cu(111) evidencing the slight rotation of overlayer and substrate lattice.
c) Low energy electron microscopy of a small bilayer flake ontop of ML-g/Cu.
d) Atomically resolved STM image of ML-g on Ir(111). The slightly rotated g lattice (green arrows) induces a moiré pattern with a large supercell (white lines).
Key publications:
Observation of a novel double layer surface oxide phase on Ni3Al(111) at low temperature, X. Ma, T. Kratky, S. Günther, Nanoscale Adv. 2019, 1, 4501–4512.
Optimizing the size of platinum nanoparticles for enhanced oxygen electro-reduction mass activity, B. Garlyyev, K. Kratzl, M. Rück, J. Michalička, J. Fichtner, J. M. Macak, T. Kratky, S. Günther, M. Cokoja, A. S. Bandarenka, A. Gagliardi, R. A. Fischer, Angew. Chem. Int. Ed. 2019, 58, 9596–9600.
The Selective Species in Ethylene Epoxidation on Silver, T. E. Jones, R. Wyrwich, S. Böcklein, E. A. Carbonio, M. T. Greiner, A. Y. Klyushin, W. Moritz, A. Locatelli, T. O. Menteş, M. A. Niño, A. Knop-Gericke, R. Schlögl, S. Günther, J. Wintterlin, S. Piccinin, ACS Catal. 2018, 8, 3844–3852.
Recent Approaches for Bridging the Pressure Gap in Photoelectron Microspectroscopy, A. Kolmakov, L. Gregoratti, M. Kiskinova, S. Günther, Top. Catal. 2016, 59, 448–468.
Desorption kinetics from a surface derived from direct imaging of the adsorbate layer, S. Günther, T. O. Menteş, M. A. Niño, A. Locatelli, S. Böcklein, J. Wintterlin, Nat. Commun. 2014, 5, 3853.