Atomic-scale studies of catalysis
by spinel oxides

Subproject P04

The spinel class of metal oxides hosts diverse materials, some of which make excellent catalysts. Fe3O4 is already the industrial catalyst for the high-temperature water-gas shift reaction (CO+H2O -> H2+CO2), but research is needed to identify the optimal replacement for the toxic Cr promoter/stabilizer. Ternary MeFe2O4 compounds (Me=Fe, Ni, Co, Mn) are active and stable for the electrochemical oxygen evolution reaction (OER). However, the structure of the active catalyst and the reaction mechanisms are unknown. While these reactions appear different, both clearly benefit from a combination of multivalent cations in the surface layers.

In this project, we will seek to learn why, using a combination of atomic-scale imaging, a host of spectroscopies, and theory. We will dope the Fe3O4(001) surface with 3d transition metals and investigate how the adsorption energies, XPS binding energies, and IRAS frequencies of H2O, CO, CO2, O2, and H2 change with sample composition all the way from isolated dopants to ternary thin films. We will use the data obtained in tightly-controlled UHV experiments to:

i) Interpret the reactivity of our model catalysts under realistic HTWGS and OER conditions.

ii) Provide the benchmark data for experiments on nominally similar powder catalysts (P10 Föttinger).

iii) Support the development of theoretical modeling (P07 Franchini).

A joint postdoc (P04-P11) will facilitate the new collaboration with P11 Backus.

Gareth S. Parkinson
PI

Expertise

The group focuses on understanding mechanisms of catalytic reactions using a combination of experimental surface science and theoretical calculations. We have access to a total of seven ultrahigh-vacuum (UHV) chambers, which allows us to conduct the following experiments:
  • 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 surface reactivity chamber, which is specifically designed to study single-crystal metal-oxide samples. Reactants are delivered to the sample by molecular beams, and products detected by a mass spectrometer. In addition to TPD, XPS, UPS, and LEIS, we will soon be able to perform infrared absorption spectroscopy (IRAS) experiments on these samples using an optimized beam geometry.

Team

Gareth S. Parkinson
PI

Publications

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43 entries « 1 of 5 »

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

Emerging applications of MXene materials in CO2 photocatalysis

Shen, Jiahui; Wu, Zhiyi; Li, Chaoran; Zhang, Chengcheng; Genest, Alexander; Rupprechter, Günther; He, Le

Emerging applications of MXene materials in CO2 photocatalysis Journal Article

In: FlatChem, 28 , pp. 100252, 2021.

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

Resolving multifrequential oscillations and nanoscale interfacet communication in single-particle catalysis

Suchorski, Yuri; Zeininger, Johannes; Buhr, Sebastian; Raab, Maximilian; Stöger-Pollach, Michael; Bernardi, Johannes; Grönbeck, Henrik; Rupprechter, Günther

Resolving multifrequential oscillations and nanoscale interfacet communication in single-particle catalysis Journal Article

In: Science, 372 (6548), pp. 1314–1318, 2021.

Links | BibTeX | Tags: P08, pre-TACO

Improved description of atomic environments using low-cost polynomial functions with compact support

Bircher, Martin P; Singraber, Andreas; Dellago, Christoph

Improved description of atomic environments using low-cost polynomial functions with compact support Journal Article

In: Machine Learning: Science and Technology, 2 (3), pp. 035026, 2021.

Abstract | Links | BibTeX | Tags: P12, pre-TACO

α-β phase transition of zirconium predicted by on-the-fly machine-learned force field

Liu, Peitao; Verdi, Carla; Karsai, Ferenc; Kresse, Georg

α-β phase transition of zirconium predicted by on-the-fly machine-learned force field Journal Article

In: Physical Review Materials, 5 (5), pp. 053804, 2021.

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

Evolutionary computing and machine learning for discovering of low-energy defect configurations

Arrigoni, Marco; Madsen, Georg K H

Evolutionary computing and machine learning for discovering of low-energy defect configurations Journal Article

In: npj Computational Materials, 7 (1), 2021.

Abstract | Links | BibTeX | Tags: P09, pre-TACO

Co3O4-CeO2 Nanocomposites for Low-Temperature CO Oxidation

Yang, Jingxia; Yigit, Nevzat; Möller, Jury; Rupprechter, Günther

Co3O4-CeO2 Nanocomposites for Low-Temperature CO Oxidation Journal Article

In: Chemistry A European Journal, 2021.

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

Direct CO2 capture and conversion to fuels on magnesium nanoparticles under ambient conditions simply using water

Rawool, Sushma A; Belgamwar, Rajesh; Jana, Rajkumar; Maity, Ayan; Bhumla, Ankit; Yigit, Nevzat; Datta, Ayan; Rupprechter, Günther; Polshettiwar, Vivek

Direct CO2 capture and conversion to fuels on magnesium nanoparticles under ambient conditions simply using water Journal Article

In: Chemical Science, 12 (16), pp. 5774–5786, 2021.

Abstract | Links | BibTeX | Tags: P08, 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

Operando Surface Spectroscopy and Microscopy during Catalytic Reactions: From Clusters via Nanoparticles to Meso-Scale Aggregates

Rupprechter, Günther

Operando Surface Spectroscopy and Microscopy during Catalytic Reactions: From Clusters via Nanoparticles to Meso-Scale Aggregates Journal Article

In: Small, 2021.

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

43 entries « 1 of 5 »