Surface structure and reactivity of
multi-component oxides at the atomic scale

Subproject P02

Multi-component metal oxides exhibit a plethora of stoichiometry-dependent structural phases at the surface, even if the composition of the bulk is kept the same. The long-term objective of P02 is to unravel the relationship between surface electronic and geometric structure and reactivity, to ultimately tune these materials for energy-related reactions such as the ORR. The project applies the surface science approach. We will grow well-defined, epitaxial perovskite thin films of LSFO and LSMO in a UHV-based PLD/surface science apparatus under tight control of the surface stoichiometry in the first project period. We will determine the coordinates of surface atoms quantitatively using LEED-IV in close collaboration with theoretical groups.

Theoretical models will also help with interpreting atomically-resolved ncAFM/STM images. These images give direct insights into the behavior of polarons in these complex materials and show how adsorbates such as O2, H2O, CO, and CO2 interact with electronic and structural defects. XPS, TPD, and FTIR of these well-defined systems will deliver desorption energies, vibrational frequencies, and spectral fingerprints. These experimental data on well-defined systems will build a bridge when tested under ‘realistic’ environments at high pressure/temperature and in aqueous solutions. They will also serve to validate ML-based theory approaches.

Ulrike Diebold
PI

Expertise

Our expertise is experimental surface science. We operate a total of seven ultrahigh-vacuum (UHV) chambers, which contain virtually all main experimental surface science techniques, as well as an (electro-)chemistry lab.

All chambers are equipped with facilities for sample preparation (sputtering/annealing/gas dosing), as well as various growth techniques (e-beam evaporators, Knudsen cells, UHV-compatible sputter deposition, pulsed laser deposition (PLD)).

Analysis techniques used in our research include:

  • Scanning Tunneling Microscopy (STM) (in UHV 4K – 300 K, electrochemical STM)
  • Atomic Force Microscopy (AFM): UHV-based (q+ sensor) and in the ambient (cantilever-based)
  • Low-Energy Electron Diffraction (LEED)
  • Reflection High Energy Diffraction (RHEED)
  • X-ray Photoelectron Spectroscopy (XPS)
  • Ultraviolet Photoelectron Spectroscopy (UPS)
  • Auger Electron Spectroscopy (AES)
  • Low-energy He+ ion scattering (LEIS)
  • Thermal Programmed Desorption Spectroscopy (TPD)

Of particular use for TACO is our combined Pulsed-Laser Deposition/Surface Science setup shown on the right-hand side. It allows the growth of multi-component metal oxides and the investigations of surface properties within the same UHV setup.

Team

Ulrike Diebold
PI

Michele Riva
co-PI

Michael Schmid
co-PI

Alexander Michael Imre
PhD Student

Erik Rheinfrank
PhD Student

Michael Brunthaler
Master Student

Florian Dörr
Master Student

Publications

2021

Ni-modified Fe3O4(001) surface as a simple model system for understanding the oxygen evolution reaction

Mirabella, Francesca; Müllner, Matthias; Touzalin, Thomas; Riva, Michele; Jakub, Zdenek; Kraushofer, Florian; Schmid, Michael; Koper, Marc T M; Parkinson, Gareth S; Diebold, Ulrike

Ni-modified Fe3O4(001) surface as a simple model system for understanding the oxygen evolution reaction Journal Article

In: Electrochimica Acta, 389 , pp. 138638, 2021.

Abstract | Links | BibTeX | Tags: P02, P04, pre-TACO

Polarons in materials

Franchini, Cesare; Reticcioli, Michele; Setvin, Martin; Diebold, Ulrike

Polarons in materials Journal Article

In: Nature Reviews Materials, 2021.

Abstract | Links | BibTeX | Tags: P02, P07, pre-TACO

Unraveling CO adsorption on model single-atom catalysts

Hulva, Jan; Meier, Matthias; Bliem, Roland; Jakub, Zdenek; Kraushofer, Florian; Schmid, Michael; Diebold, Ulrike; Franchini, Cesare; Parkinson, Gareth S

Unraveling CO adsorption on model single-atom catalysts Journal Article

In: Science, 371 (6527), pp. 375–379, 2021.

Abstract | Links | BibTeX | Tags: P02, P04, P07, pre-TACO

2020

IrO2 Surface Complexions Identified through Machine Learning and Surface Investigations

Timmermann, Jakob; Kraushofer, Florian; Resch, Nikolaus; Li, Peigang; Wang, Yu; Mao, Zhiqiang; Riva, Michele; Lee, Yonghyuk; Staacke, Carsten; Schmid, Michael; Scheurer, Christoph; Parkinson, Gareth S; Diebold, Ulrike; Reuter, Karsten

IrO2 Surface Complexions Identified through Machine Learning and Surface Investigations Journal Article

In: Physical Review Letters, 125 (20), pp. 206101, 2020.

Abstract | Links | BibTeX | Tags: P02, P04, pre-TACO

Atomically resolved surface phases of La0.8Sr0.2MnO3(110) thin films

Franceschi, Giada; Schmid, Michael; Diebold, Ulrike; Riva, Michele

Atomically resolved surface phases of La0.8Sr0.2MnO3(110) thin films Journal Article

In: Journal of Materials Chemistry A, 8 (43), pp. 22947–22961, 2020.

Abstract | Links | BibTeX | Tags: P02, pre-TACO

Electrochemical Stability of the Reconstructed Fe3O4(001) Surface

Grumelli, Doris; Wiegmann, Tim; Barja, Sara; Reikowski, Finn; Maroun, Fouad; Allongue, Philippe; Balajka, Jan; Parkinson, Gareth S; Diebold, Ulrike; Kern, Klaus; Magnussen, Olaf M

Electrochemical Stability of the Reconstructed Fe3O4(001) Surface Journal Article

In: Angewandte Chemie - International Edition, 59 (49), pp. 21904–21908, 2020.

Abstract | Links | BibTeX | Tags: P02, P04, pre-TACO

2019

Local Structure and Coordination Define Adsorption in a Model Ir1/Fe3O4 Single-Atom Catalyst

Jakub, Zdenek; Hulva, Jan; Meier, Matthias; Bliem, Roland; Kraushofer, Florian; Setvin, Martin; Schmid, Michael; Diebold, Ulrike; Franchini, Cesare; Parkinson, Gareth S

Local Structure and Coordination Define Adsorption in a Model Ir1/Fe3O4 Single-Atom Catalyst Journal Article

In: Angewandte Chemie - International Edition, 58 (39), pp. 13961–13968, 2019.

Abstract | Links | BibTeX | Tags: P02, P04, P07, pre-TACO

Preface: Surface Science of functional oxides

Diebold, Ulrike; Rupprechter, Günther

Preface: Surface Science of functional oxides Journal Article

In: Surface Science, 681 , pp. A1, 2019.

Links | BibTeX | Tags: P02, P08, pre-TACO

Interplay between Adsorbates and Polarons: CO on Rutile TiO2(110)

Reticcioli, Michele; Sokolović, Igor; Schmid, Michael; Diebold, Ulrike; Setvin, Martin; Franchini, Cesare

Interplay between Adsorbates and Polarons: CO on Rutile TiO2(110) Journal Article

In: Physical Review Letters, 122 (1), pp. 016805, 2019.

Abstract | Links | BibTeX | Tags: P02, P07, pre-TACO

2017

Polaron-Driven Surface Reconstructions

Reticcioli, Michele; Setvin, Martin; Hao, Xianfeng; Flauger, Peter; Kresse, Georg; Schmid, Michael; Diebold, Ulrike; Franchini, Cesare

Polaron-Driven Surface Reconstructions Journal Article

In: Physical Review X, 7 (3), pp. 031053, 2017.

Abstract | Links | BibTeX | Tags: P02, P03, P07, pre-TACO