Thin Films

The activities of the group are centered around thin film catalyst models. Such models mimic relevant aspects of a real world catalysts, but have a reduced complexity. That allows us to understand catalytic processes in detail. Central activities of the group are the development of thin film preparation recipes and the study of thermal and electrocatalytic reactions at the thin film / gas or liquid interfaces.

Supported catalysts may be mimicked by deposition of metallic aggregates. Several surface-sensitive experimental methods (XPS, TPD, STEM, EELS, IR surface action spectroscopy) are applied under vacuum conditions and at elevated pressures.

Group Members

Name	Email
Dr. Ane Etxebarria	etxebarria@fhi-berlin.mpg.de
Dr. Afshan Jamshaid	jamshaid@fhi-berlin.mpg.de
Dr. David Koshy	koshy@fhi-berlin.mpg.de
Dr. Helmut Kuhlenbeck	kuhlenbeck@fhi-berlin.mpg.de
Dr. Sotiris Tsatsos	tsatsos@fhi-berlin.mpg.de
Walter Wachsmann	wachsmann@fhi-berlin.mpg.de
	_.

Research

SPM

Scanning probe microscopy is applied to investigate surface structures. Sometimes also X-ray based structural methods or I/V-LEED structural analysis may be used.

XPS

With XPS the elemental composition of the surface and the electronic structure of the surface atoms is investigated. This may also involve adsorbates and/or deposited aggregates.

HREELS

HREELS is a method for the study of vibrations and electronic excitations at the surface. It may also reveal relevant information about deposited aggregates and adsorbates. In this method electrons are scattered inelastically at a surface. Hereby the electrons suffer an energy loss which is the desired information.

Action Spectroscopy

Surface action spectroscopy is a newly developed vibrational method. The investigated surface is covered with weakly bound atoms (the messengers) which are desorbed when infrared radiation [coming from the free electron laser (FEL) of the Institute] excites a vibration of the surface.

Recent Publications

2022

Y. Liu, Z. Han, S. Gewinner, W. Schöllkopf, S.V. Levchenko, H. Kuhlenbeck and B. Roldan Cuenya: Adatom Bonding Sites in a Nickel-Fe₃O₄(001) Single-Atom Model Catalyst and O₂ Reactivity Unveiled by Surface Action Spectroscopy with Infrared Free-Electron Laser Light. Angewandte Chemie International Edition 61 (28), e202202561 (2022).

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DOI

publisher-version

2021

Y. Liu, Y. Peng, M. Naschitzki, S. Gewinner, W. Schöllkopf, H. Kuhlenbeck, R. Pentcheva and B. Roldan Cuenya: Surface oxygen Vacancies on Reduced Co₃O₄(100): Superoxide Formation and Ultra-Low-Temperature CO Oxidation. Angewandte Chemie International Edition 60 (30), 16514–16520 (2021).

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DOI

publisher-version

Talks

2021

Kuhlenbeck, H.: Model Studies of Crystalline Thin Oxide Films: Surface Action Spectroscopy and Electrochemistry. FHI-Workshop on Current Research Topics at the FHI, Potsdam, Germany (2021)

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2019

Kuhlenbeck, H.: High Resolution Electron Energy Loss Spectroscopy. IMPRS Fall Block Course 2019, Unifying Concepts in Spectroscopy, Berlin, Germany (2019)

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Kuhlenbeck, H.: Surface Action Spectroscopy With Inert Gas Messengers. Seminar, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Sciences, Suzhou, China (2019)

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Former Group Photos