Dynamics at Electrocatalytic Interfaces

Dynamics at Electrocatalytic Interfaces

Comprehensive and fundamental understanding of the physical and chemical processes during electrochemical energy conversion is critical to optimize electrochemical devices. Therefore, the fundamental research has to be coordinated with the applied research and technologically realization. Our key reactions comprise the electrochemical conversion of greenhouse gases and environmentally pollutant molecules to store energy from renewable power sources and to produce feedstock chemicals and fuels.

In particular, we aim to identify key properties to efficiently produce hydrocarbons, like ethylene, and alcohols, like ethanol, from CO2 as well as H2 and ammonia from water and nitrate in CO2RR, OER, and NO3RR. All these reactions comprise bond-breaking and ‑making steps which we aim to understand on electrocatalytically-relevant time scales.

Our approach comprises well-defined model catalysts in which key properties of realistic catalysts (supported nanoparticles or catalysts coatings) can be tailored and studied separately. We utilize, for example, size- and shape-selected nanoparticles of metals and metal oxides as well as thin films. We focus on the catalysts systems based on relevant, abundant, inexpensive 3d transition metals such as Co, Fe, Ni, Cu, and Zn but also IrOx for acidic OER.

In addition to the comprehensive characterization of the pre- and post-catalytic states using the broad range of methodologies available at the Department of Interface Science, we achieve operando insights on the adaptations of the (bulk) structure, the near-surface chemistry, the ensemble of surface adsorbates as well as the electrolyte state primarily via operando electrochemical (grazing incidence and high-energy) X-ray diffraction, surface-enhanced Raman and X-ray photoemission spectroscopy (s. figure above). Therefore, we utilize lab-based experimental setups and conduct experiments at synchrotron facilities. Furthermore, we strongly collaborate with the Research Groups of Liquid Electron Microscopy (S.W. Chee) and Advanced X-ray Spectroscopy (J. Timoshenko) to better understand the (reversible) changes of the nanocatalysts morphology as well as local atomic structure under electrocatalytic conditions.

Group Members

Name Email
Dr. Lichen Bai
Dr. Arno Bergmann
Johannes Düde
Dr. Matias Herran
Dr. Leon Jacobse
Samuele Lasagna
Eric Liberra
Dr. Huimin Liu
Ömer F. Sadak
Timon Wagner

Recent Publications



H. Liu, L. Bai, A. Bergmann, B. Roldan Cuenya and J. Luo: Electrocatalytic reduction of nitrogen oxide species to ammonia. Chem, in press.
E. Davis, A. Bergmann, H. Kuhlenbeck and B. Roldan Cuenya: Facet Dependence of the Oxygen Evolution Reaction on Co3O4, CoFe2O4, and Fe3O4 epitaxial film electrocatalysts. Journal of the American Chemical Society 146 (20), 13770–13782 (2024).
A. Herzog, M. Lopez-Luna, H. Jeon, C. Rettenmaier, P. Grosse, A. Bergmann and B. Roldan Cuenya: Operando Raman spectroscopy uncovers hydroxide and CO species enhance ethanol selectivity during pulsed CO2 electroreduction. Nature Communications 15, 3986 (2024).
L. Bai, F. Franco, J. Timoshenko, C. Rettenmaier, F. Scholten, H. Jeon, A. Yoon, M. Rüscher, A. Herzog, F. Haase, S. Kühl, S.W. Chee, A. Bergmann and B. Roldan Cuenya: Electrocatalytic Nitrate and Nitrite Reduction toward Ammonia using Cu2O Nanocubes: Active Species and Reaction Mechanisms. Journal of the American Chemical Society 146 (14), 9665–9678 (2024).
T. Hannappel, S. Shekarabi, W. Jaegermann, E. Runge, J.P. Hofmann, R. van de Krol, M.M. May, A. Bergmann, A. Bund, C. Cierpka, C. Dreßler, F. Dionigi, D. Friedrich, M. Favaro, F. Hess, S. Krischok, M. Kurniawan, K. Lüdge, Y. Lei, A. Paszuk, B. Roldan Cuenya, P. Schaaf, R. Schmidt-Grund, W.G. Schmidt, P. Strasser, E. Unger, M.F. Vasquez Montoya, D. Wang and H. Zhang: Integration of Multijunction Absorbers and Catalysts for Efficient Solar-Driven Artificial Leaf Structures: A Physical and Materials Science Perspective. Solar RRL 2301047 (2024).
F. Haase, E. Ortega, S. Saddeler, F. Schmidt, D. Cruz, F. Scholten, M. Rüscher, A. Martini, H. Jeon, A. Herzog, U. Hejral, E. Davis, J. Timoshenko, A. Knop-Gericke, T. Lunkenbein, S. Schulz, A. Bergmann and B. Roldan Cuenya: Role of Fe Decoration on the Oxygen Evolving State of Co3O4 Nanocatalysts. Energy & Environmental Science 17 (5), 2046–2058 (2024).
C. Rettenmaier, A. Herzog, D. Casari, M. Rüscher, H. Jeon, D. Kordus, M. Lopez-Luna, S. Kühl, U. Hejral, E. Davis, S.W. Chee, J. Timoshenko, D.T.L. Alexander, A. Bergmann and B. Roldan Cuenya: Operando insights into correlating CO coverage and Cu-Au alloying with the selectivity of Au NP-decorated Cu2O nanocubes during the electrocatalytic CO2 reduction. EES Catalysis 2 (1), 311–323 (2024).
F. Yang, M. Lopez-Luna, F. Haase, D. Escalera Lopez, A. Yoon, M. Rüscher, C. Rettenmaier, H. Jeon, E. Ortega, J. Timoshenko, A. Bergmann, S.W. Chee and B. Roldan Cuenya: Spatially and Chemically Resolved Visualization of Fe Incorporation into NiO Octahedra during the Oxygen Evolution Reaction. Journal of the American Chemical Society 145 (39), 21465–21474 (2023).
S. Oener, A. Bergmann and B. Roldan Cuenya: Designing active oxides for a durable oxygen evolution reaction. Nature Synthesis 2, 817–827 (2023).
R. Amirbeigiarab, J. Tian , A. Herzog, C. Qiu, A. Bergmann, B. Roldan Cuenya and O.M. Magnussen: Atomic-scale surface restructuring of copper electrodes under CO2 electroreduction conditions. Nature Catalysis 6 (9), 837–846 (2023).
E. Davis, A. Bergmann, C. Zhan, H. Kuhlenbeck and B. Roldan Cuenya: Comparative study of Co3O4(111), CoFe2O4(111), and Fe3O4(111) thin film electrocatalysts for the oxygen evolution reaction. Nature Communications 14, 4791 (2023).
F. Yang, M. Lopez-Luna, F. Haase, D. Escalera Lopez, A. Yoon, A. Kosari, M. Porcu, A. Bergmann, B. Roldan Cuenya and S.W. Chee: Tracking the Incorporation of Fe into NiO Electrocatalysts during Reaction with Liquid Phase Electron Microscopy and Time-Resolved Elemental Mapping. Microscopy and Microanalysis 29 (Suppl 1), 1302–1303 (2023).
J. Velasco Vélez, J. Poon, D. Gao, C.-H. Chuang, A. Bergmann, T. Jones, S.-C. Haw, J.-M. Chen, E. Carbonio, R. Mom, D. Ivanov, R. Arrigo, B. Roldan Cuenya, A. Knop-Gericke and R. Schlögl: Cationic Copper Species Stabilized by Zinc during the Electrocatalytic Reduction of CO2 Revealed by In Situ X-Ray Spectroscopy. Advanced Sustainable Systems 7 (5), 2200453 (2023).
G. Wartner, D. Hein, A. Bergmann, R. Wendt, B. Roldan Cuenya and R. Seidel: Insights into the electronic structure of Fe-Ni thin-film catalysts during oxygen evolution reaction using operando resonant Photoelectron Spectroscopy. Journal of Materials Chemistry A 11 (15), 8066–8080 (2023).
J. Timoshenko, F. Haase, S. Saddeler, M. Rüscher, H. Jeon, A. Herzog, U. Hejral, A. Bergmann, S. Schulz and B. Roldan Cuenya: Deciphering the Structural and Chemical Transformations of Oxide Catalysts during Oxygen Evolution Reaction Using Quick X-ray Absorption Spectroscopy and Machine Learning. Journal of the American Chemical Society 145 (7), 4065–4080 (2023).
F. Haase, A. Bergmann, T. Jones, J. Timoshenko, A. Herzog, H. Jeon, C. Rettenmaier and B. Roldan Cuenya: Size effects and active state formation of cobalt oxide nanoparticles during the oxygen evolution reaction. Nature Energy 7 (8), 765–773 (2022).
F. Haase, A. Rabe, F. Schmidt, A. Herzog, H. Jeon, W. Frandsen, P.V. Narangoda, I. Spanos, K.F. Ortega, J. Timoshenko, T. Lunkenbein, M. Behrens, A. Bergmann, R. Schlögl and B. Roldan Cuenya: Role of Nanoscale Inhomogeneities in Co2FeO4 Catalysts during the Oxygen Evolution Reaction. Journal of the American Chemical Society 144 (27), 12007–12019 (2022).
J. Timoshenko, A. Bergmann, C. Rettenmaier, A. Herzog, R. Aran Ais, H. Jeon, F. Haase, U. Hejral, P. Grosse, S. Kühl, E. Davis, J. Tian, O. Magnussen and B. Roldan Cuenya: Steering the structure and selectivity of CO2 electroreduction catalysts by potential pulses. Nature Catalysis 5 (4), 259–267 (2022).
N. Daems, D. Choukroun, P. Merino, C. Rettenmaier, L. Pacquets, A. Bergmann, G. Santoro, L. Vázquez, L. Martínez, B. Roldan Cuenya, J.A. Martín Gago and T. Breugelmans: Steering Hydrocarbon Selectivity in CO2 Electroreduction over Soft-Landed CuOx Nanoparticle-Functionalized Gas Diffusion Electrodes. ACS Applied Materials and Interfaces 14 (2), 2691–2702 (2022).
S. Saddeler, G. Bendt, S. Salamon, F. Haase, J. Landers , J. Timoshenko, C. Rettenmaier, H. Jeon, A. Bergmann, H. Wende, B. Roldan Cuenya and S. Schulz: Influence of the cobalt content in cobalt iron oxides on the electrocatalytic OER activity. Journal of Materials Chemistry A 9 (45), 25381–25390 (2021).
C. Zhan, F. Dattila, C. Rettenmaier, A. Bergmann, S. Kühl, R. García-Muelas, N. Lopez and B. Roldan Cuenya: Revealing the CO Coverage Driven C-C Coupling Mechanism for Electrochemical CO2 Reduction on Cu2O Nanocubes via Operando Raman Spectroscopy. ACS Catalysis 11 (13), 7694–7701 (2021).
A. Herzog, A. Bergmann, H. Jeon, J. Timoshenko, S. Kühl, C. Rettenmaier, M. Lopez-Luna, F. Haase and B. Roldan Cuenya: Operando Investigation of Ag‐Decorated Cu2O Nanocube Catalysts with Enhanced CO2 Electroreduction toward Liquid Products. Angewandte Chemie International Edition 60 (13), 7426–7435 (2021).
N.J. Divins, D. Kordus, J. Timoshenko, I. Sinev, I. Zegkinoglou, A. Bergmann, S.W. Chee, S. Widrinna, O. Karslıoğlu, H. Mistry, M. Lopez Luna, J.Q. Zhong, A.S. Hoffmann, A. Boubnov, J.A. Boscoboinik, M. Heggen, R.E. Dunin-Borkowski, S.R. Bare and B. Roldan Cuenya: Operando high-pressure investigation of size-controlled CuZn catalysts for the methanol synthesis reaction. Nature Communications 12, 1435 (2021).
R. Rizo, A. Bergmann, J. Timoshenko, F. Scholten, C. Rettenmaier, H. Jeon, Y.-T. Chen, A. Yoon, A. Bagger, J. Rossmeisl and B. Roldan Cuenya: Pt-Sn-Co nanocubes as highly active catalysts for ethanol electro-oxidation. Journal of Catalysis 393, 247–258 (2021).
C. Rettenmaier, R. Aran Ais, J. Timoshenko, R. Rizo, H. Jeon, S. Kühl, S.W. Chee, A. Bergmann and B. Roldan Cuenya: Enhanced Formic Acid Oxidation over SnO2-decorated Pd Nanocubes. ACS Catalysis 10 (24), 14540–14551 (2020).
D. Hein, G. Wartner, A. Bergmann, M. Bernal, B. Roldan Cuenya and R. Seidel: Reversible Water-Induced Phase Changes of Cobalt Oxide Nanoparticles. ACS Nano 14 (11), 15450–15457 (2020).
H.N. Nong, L. Falling, A. Bergmann, M. Klingenhof, H.P. Tran, C. Spöri, R. Mom, J. Timoshenko, G. Zichittella, A. Knop-Gericke, S. Piccinin, J. Pérez-Ramírez, B. Roldan Cuenya, R. Schlögl, P. Strasser, D. Teschner and T. Jones: Key role of chemistry versus bias in electrocatalytic oxygen evolution. Nature 587 (7834), 408–413 (2020).
F. Dionigi, Z. Zeng, I. Sinev, T. Merzdorf, S. Deshpande, M.B. Lopez, S. Kunze, I. Zegkinoglou, H. Sarodnik, D. Fan, A. Bergmann, J. Drnec, J.F.D. Araujo, M. Gilech, D. Teschner, J. Zhu, W. Li, J.P. Greeley, B. Roldan Cuenya, P. Strasser and P. Strasser: In-situ structure and catalytic mechanism of NiFe and CoFe layered double hydroxides during oxygen evolution. Nature Communications 11, 2522 (2020).
A. Bergmann and B. Roldan Cuenya: Operando Insights into Nanoparticle Transformations during Catalysis. ACS Catalysis 9 (11), 10020–10043 (2019).
M. Bernal, A. Bagger, F. Scholten, I. Sinev, A. Bergmann, M. Ahmadi, J. Rossmeisl and B. Roldan Cuenya: CO2 electroreduction on copper-cobalt nanoparticles: Size and composition effect. Nano Energy 53, 27–36 (2018).
K. Klingan, T. Kottakkat, Z.P. Jovanov, S. Jiang, C. Pasquini, F. Scholten, P. Kubella, A. Bergmann, B. Roldan Cuenya, C. Rot and H. Dau: Reactivity Determinants in Electrodeposited Cu Foams for Electrochemical CO2 Reduction. ChemSusChem 11 (19), 3449–3459 (2018).


non peer-reviewed

B. Roldan Cuenya, A. Bergmann, C. Kley, P. Grosse and S. Oener: Klimaneutralität mittels Katalyse. Jahrbuch / Max-Planck-Gesellschaft 2020, 11659628 (2021).
B. Roldan Cuenya, A. Bergmann, C. Kley, P. Grosse and S. Oener: Maßgeschneiderte Katalysatoren für die grüne Energiewirtschaft. Highlights aus dem Jahrbuch der Max-Planck-Gesellschaft 2020, 8–10 (2021).
B. Roldan Cuenya, A. Bergmann, C. Kley, P. Grosse and S. Oener: Tailor-made catalysts for the green energy industry. Highlights from the yearbook of the Max Planck Society 2020, 8–10 (2021).


Bergmann, A.: Operando Investigations of the Cu Solid-Liquid Interface Under Stationary and Pulsed CO2RR Conditions. 15th International Fischer Symposium, Seeon, Germany (2022)
Bergmann, A.: Surface Reactivity of Co-based Model Catalysts in Oxidation Electrocatalysis. International CataLysis Networking Conference 2022, Kassel, Germany (2022)
Bergmann, A.: Understanding Redox Electrochemistry and Active State Formation of Electrocatalysts: Operando Insights Into Size Effects and Dynamics. FHI-Workshop on Current Research Topics at the FHI, Online Event (2021)
Bergmann, A.: In situ Studies to Understand (Electro)chemical Energy Conversion–XAFS and XRD on Nanocatalysts during Alcohol Oxidation and Oxygen Evolution. 13th EERA AMPEA Joint Programme Steering Committee and AMPEA-EERA workshop: Synchrotron Radiation and Neutron Scattering for Energy Materials, Berlin, Germany (2018)
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