Research Profile
Univ.-Prof. Dr. Hans-Peter Steinrück
Physical Chemistry, University Erlangen-Nürnberg, Germany
Prof. Hans-Peter Steinrück is investigating the physics and chemistry of surfaces since 30 years, 1982-1985 at the TU Graz / Austria, 1985/1986 at Stanford University / USA, 1986-1993 at the TU München / Germany, 1993 at Rutgers University / USA, 1994-1998 at the Universität Würzburg / Germany und since 1998 at the Universität Erlangen-Nürnberg / Germany. In addition, he is Guest Professor at the University of Science and Technology of China (USTC) in Hefei / China since 2009.
In March 1998 Prof. Steinrück was appointed to the Chair of Physical Chemistry II at the Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and since then he built up an active international and interdisciplinary research group. He is Principle Investigator (PI) in the Cluster-of-Excellence EXC 315/1 "Engineering of Advanced Materials - Hierarchical Structure Formation for Functional Devices", which was granted to the Universität Erlangen-Nürnberg in 2007. This adds to the funding of his group by the German Science Foundation (DFG, via collaborative research centers (SFBs) 292, 338, 410, 583, 953, priority programs (SPPs) 1091, 1191, and individual grants), BMBF, EU, DAAD, FCI, State of Bavaria, Max-Buchner Research Foundation und Alexander-von-Humboldt Foundation.
The scientific output of this research is documented in more than 210 publications in refereed international journals and more than 135 invited lectures at international conferences and scientific institutions.
Presently, Hans-Peter Steinrück's research group numbers over 20 PhD students and postdoctoral researchers, and he has graduated 35 PhD students and mentored 4 Habilitations and 11 postdocs in his professorial career. His former students and postdocs have been offered attractive positions in worldwide leading companies (e.g. Siemens, Infineon, IBM, ThyssenKrupp, BMW) or academic institutions; 9 of them occupy positions as professor at Universities in Germany, UK or China.
The mission of the Steinrück group is to provide a perfect environment to perform surface and interface science at the highest possible level and to create an attractive and international competitive atmosphere for researchers at all stages of their career, from BSc, MSc and PhD students to postdocs and junior group leaders. The research activities follow an interdisciplinary approach with numerous local, national and international cooperations with colleagues in physics, chemistry, chemical engineering, and materials science, which are documented in collaborative research projects and publications. Specific emphasis is also given to the education of undergraduate students, in lectures, seminars and lab courses.
Goals and Methods:
The activities of the Steinrück group focus in the area of surface and interface science with main research interests in:
| 1) | Development of new materials with novel electronic, geometric and chemical properties |
| 2) | Investigation of elementary steps of surface reactions |
| 3) | Construction of advanced scientific apparatus |
These studies aim at a fundamental physical and chemical understanding of the mechanisms and processes involved, at an atomic level. A large variety of state-of-the art experimental techniques is applied, partly utilizing synchrotron radiation. The methods range from high resolution X-ray photoelectron spectroscopy (XPS), angle-resolved UV- und X-ray photoelectron spectroscopy (ARUPS, ARXPS), Auger electron spectroscopy (AES, XAES), photoelectron diffraction (PED), electron energy loss spectroscopy (ELS), near edge X-ray absorption fine structure measurements (NEXAFS), temperature programmed desorption (TPD), work function measurements, low energy ion scattering (LEIS) and molecular beam methods (Maxwellian beams and supersonic beams)) to low energy electron diffraction, (LEED, including LEED-IV analysis), scanning tunnelling microscopy (STM), scanning electron and scanning Auger microscopy (SEM, SAM). The measurements at synchrotron radiation facilities are performed since 1986, mainly at BESSY and BESSY II, but also at MAX-lab, ELETTRA, SSRL, ALS and ESRF. In addition, the development of experimental methods is put forward, concerning technical improvements as well as the understanding of the underlying fundamental concepts.
Research Highlights:
In the following the ongoing projects and their major results are summarized and important past highlights are briefly addressed.
"Ionic Liquid Surface Science" concerns pioneering work addressing the liquid/vacuum and liquid/solid interface of ionic liquids (ILs). Using an interdisciplinary approach, in cooperation with the synthetically oriented group of Prof. Peter Wasserscheid, the fundamental relations between the chemical structure of known and new ILs and their bulk and surface properties as well as their reactivity are studied. In the focus are non-functionalized and functionalized ILs, mixtures of ILs, transition metal complexes dissolved in ILs, in situ reaction studies and the interaction of gases and organic molecules with ILs. The studies benefit from the extremely low vapor pressure of most ILs, which enables their investigation with surface science methods in ultra high vacuum, in particular with angle-resolved X-ray photoelectron spectroscopy (ARXPS).
The adsorption and reactivity of redox-active metalloporphyrins are studied by the Steinrück group in the collaborative research center SFB 583 "Redox Active Metal Complexes - Controlling Reactivity Through Molecular Architectures". Specific attention is paid to well-defined porpyhrin layers, in particular monolayers, on various metal surfaces. The investigations focus on novel surface reactions, such as the direct in situ metalation of adsorbed free base porphyrins, in order to produce highly reactive metalloporphyrins), and the adsorption and complexation of small molecules (NH3, NO, CO, O2) at the coordinated metal centers. The reactivity of these centers (Fe, Co, Ni, Zn, Cu) can be tailored by the electronic interaction with the underlying metal surface (substrate) by variation of either the substrate or the distance between substrate and metal center by the attachment of appropriate ligands at the periphery of the macrocycle. Additional important aspects are the intramolecular conformation of the porphyrins and other tetrapyrroles and the formation of supramolecular networks. The applied experimental methods are mainly photoelectron spectroscopy and scanning tunneling microscopy.
In-situ studies of surface reactions provide detailed insights in the relevant elementary steps during adsorption and reaction of molecules on single crystal surfaces and during their thermal evolution. In 1999, the Steinrück group built up a UHV apparatus, which combines high resolution X-ray photoelectron spectroscopy with a supersonic molecular beam. At a third generation synchrotron facility, such as BESSY II in Berlin, this setup allows to measure highly resolved XP spectra with very short measurement times (down to 1 second/spectrum) as function of pressure, temperature, structure or coverage. Due to the high resolution, different surface species can be identified and quantified. This enables to derive detailed conclusions on reaction mechanisms and kinetics. Recently, fundamental insights have been obtained concerning the adsorption of small molecules (NO, O2, CO2, H2O, SO2), the oxidation of CO or atomic sulphur, and the adsorption of various saturated and non-saturated hydrocarbons (CH4, C2H2, C2H4, C2H6, C6H6) on flat and stepped metal surfaces and also on oxide surfaces.
A related topic is "High pressure" XPS in the so-called "pressure gap". These studies aim at bridging the gap between classical UHV experiments on model systems and the ambient conditions in real catalysis. Using a spectrometer built in 2001/2002 that is equipped with a triply differentially pumped electron analyzer and a differentially pumped Al-Kα source, XPS measurements can be performed up to 1 mbar, i.e. up to pressures close to those relevant in real systems. In the recent past, major topics in this project were, e.g., methanol steam reforming at PdZn catalysts and the catalytic properties of nanosized Au.
Since 2010 the Steinrück group studies the chemical modification of supported graphene (on metal substrates) by heteroatoms. (SFB 953 "Synthetic carbon allotropes"). Strategies for the modification are the preadsorption or codeposition of N- or B-containing molecules, the dosage of reactive species using a supersonic molecular beam, functionalization with rylenes and porphyrins, hydrogenation to graphane and intercalation of metals. In addition, the in-situ synthesis of macromolecular structures is foreseen on metal surfaces. As experimental method, predominantly X-ray photoelectron spectroscopy is applied, using synchrotron radiation at BESSY II.
Electron Induced Deposition (EBID) of nanostructures on different surfaces (metals, semiconductors and oxides) is one further major research activity. The Steinrück group could demonstrate that upon electron beam-induced deposition of adsorbed precursor molecules, e.g. Fe(CO)5, under ultra high vacuum conditions, a hitherto unreached purity of the metal deposits of >95% can be achieved, with lateral dimensions down to < 10 nm. Recently, a new and promising variant of electron beam-induced processing of surfaces was developed for the production of clean and laterally well-defined nanostructures. In this novel two step approach first, an oxide surface is locally "activated" by the highly focussed electron beam prior to dosing the precursor gas. Secondly, the preactivated structure is “developed” by exposing the surface to the precursor gas, which dissociates only in the preactivated regions. A further important goal is the investigation of fundamental aspects of electron-precursor and electron-substrate interactions.
Other research activities, for which the research team of Prof. Steinrück has received significant attention and recognition in the past, are:
Electronic Structure of ultrathin metal layers and alloys: Preparation, characterization, electronic band structure, and correlations between electronic and chemical properties.
Oxide surfaces and surface oxides: Characterization, growth, deposition of metals, adsorption of small molecules, strong metal support interaction (SMSI).
Electronic properties, structure and orientation of small molecules on metal surfaces: Interplay of adsorbate-adsorbate and adsorbate-substrate interactions, one- and two-dimensional adsorbate band structures, pure and coadsorbed molecular layers, angle-resolved UV photoelectron spectroscopy, symmetry selection rules, near edge X-ray absorption spectroscopy (NEXAFS), LEED IV analysis.
Molecular beam studies of gas-surface interactions: Microscopic reversibility, detailed balance, energy and angular dependence of sticking coefficients, angular dependence of desorbing molecules, adsorption kinetics and dynamics.
Electronic properties, 3D band structure and valence band offsets of II-VI semiconductors and heteroepitactical layers: Experimental determination of the band structure, UV photoelectron spectroscopy, electron energy loss spectroscopy, ZnSe, BeTe, CdTe.
Photoelectron holography: First experimental demonstration of the applicability of this approach (sulphur on Ni(111)); fundamental experimental studies concerning photoelectron diffraction.
Final state effects in photoelectron spectroscopy: Photon energy dependence of the cross section, shape resonances, dynamical Jahn-Teller effects in UV photoelectron spectroscopy, vibrational excitations in X-ray photoelectron spectroscopy.
Development of new experimental apparatus: Setups for measuring the angular dependence of sticking coefficients and desorption fluxes; simple helium scattering apparatus; UHV chambers for fast XPS (down to 1 sec per spectrum), high pressure XPS (up to 1 mbar) and microcalorimetry.
Selected Publications:
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C. Kolbeck, I. Niedermaier, N. Taccardi, P. S. Schulz, F. Maier, P. Wasserscheid, H.-P. Steinrück Monitoring of Liquid-Phase Organic Reactions by Photoelectron Spectroscopy Angew. Chem. Int. Ed. 51 (2012) 2610-2613 VIP article & Inside Back Cover. |
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J. M. Englert, C. Dotzer, G. Yang, M. Schmid, C. Papp, J. M. Gottfried, H.-P. Steinrück, E. Spiecker, F. Hauke, A. Hirsch Covalent Bulk Functionalization of Graphene Nature Chem. 3 (2011) 279-286 Cover. |
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H.-P. Steinrück, J. Libuda, P. Wasserscheid, T. Cremer, C. Kolbeck, M. Laurin, F. Maier, M. Sobota, P. S. Schulz, M. Stark Surface Science and Model Catalysis with Ionic Liquid-Modified Materials Adv. Mater. 23 (2011) 2571-2587. |
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K. R. J. Lovelock, I. J. Villar-Garcia, F. Maier, H.-P. Steinrück, P. Licence Photoelectron Spectroscopy of Ionic Liquid Based Interfaces Chem. Rev. 110 (2010) 5158-5190. |
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M.-M. Walz, M. Schirmer, F. Vollnhals, T. Lukasczyk, H.-P. Steinrück, H. Marbach Electrons as "Invisible Ink" – Fabrication of Nanostructures by Local Electron Beam Induced Activation of SiOx Angew. Chem. Int. Ed. 49 (2010) 4669-4673 VIP article & Cover. |
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R. Streber, C. Papp, M. P. A. Lorenz, A. Bayer, R. Denecke, H.-P. Steinrück Sulfur Oxidation on Pt(355): It is the Steps! Angew. Chem. Int. Ed. 48 (2009) 9743-9746. |
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F. Buchner, K. Seufert, W. Auwärter, D. Heim, J. V. Barth, K. Flechtner, J. M. Gottfried, H.-P. Steinrück, H. Marbach NO-induced reorganization of porphyrin arrays ACS Nano 3 (2009) 1789-1794. |
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K. Flechtner, A. Kretschmann, H.-P. Steinrück, J. M. Gottfried NO-induced reversible switching of the electronic interaction between a porphyrin-coordinated cobalt ion and a silver surface J. Am. Chem. Soc. 129 (2007) 12110-12111. |
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J. M. Gottfried, K. Flechtner, A. Kretschmann, T. Lukasczyk, H.-P. Steinrück Direct synthesis of a metalloporphyrin complex on a surface J. Am. Chem. Soc. 128 (2006) 5644-5645. |
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F. Maier, J. M. Gottfried, J. Rossa, D. Gerhard, P. S. Schulz, P. Wasserscheid, H.-P. Steinrück Surface enrichment and depletion effects of ions dissolved in an ionic liquid. A X-ray photoelectron spectroscopy (XPS) study Angew. Chem. Int. Ed. 45 (2006) 7778-7780. |
Selected Reviews:
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H.-P. Steinrück Recent developments in the study of ionic liquid interfaces using X-ray photoelectron spectroscopy and potential future directions Phys. Chem. Chem. Phys. 14 (2012) 5010-5029. INVITED Perspective Article |
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K. R. J. Lovelock, I. J. Villar-Garcia, F. Maier, H.-P. Steinrück, P. Licence Photoelectron Spectroscopy of Ionic Liquid-Based Interfaces Chem. Rev. 110 (2010) 5158-5190. |
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H.-P. Steinrück Surface Science goes liquid ! Surf. Sci. 604 (2010) 481-485. |
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G. Held and H.-P. Steinrück Cyclic hydrocarbons Landolt-Börnstein “Physics of Covered Solid Surfaces – Adsorbed Layers on Surfaces ”, Editor: H. P. Bonzel, Vol. III/42, Subvolume A4, Chapter 3.8.7. (2005) pp. 300-369. INVITED contribution. |
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M. Zharnikov and H.-P. Steinrück Holography with photoelectrons: A direct approach J. Phys. Condens. Matter 13 (2001) 10533-10560. INVITED Article. |
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H.-P. Steinrück Angle-resolved photoemission studies of adsorbed hydrocarbons J. Phys. Condens. Matter 8 (1996) 6465-6509. INVITED Topical Review article. |
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H.-P. Steinrück Angle-resolved UV-photoelectron spectroscopy Vacuum 45 (1994) 715-731. INVITED contribution to Special Edition on "Modern Methods of Surface Science and Analysis" |
A full list of publications of the members of the Steinrück group since 1998 can be found here.
A full list of publications of Univ.-Prof. Hans-Peter Steinrück since 1984 can be found here.