Publikationsliste

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2000    1999    1998    1997    1996    1995    1994    1993    1992    1991    1990    1989    1988

vollständige Publikationsliste: Publons (former: ResearcherID) oder Researchgate Joachim Bansmann on ResearchGate

ORCID: orcid.org/0000-0003-3205-7450

2020

Adlayer Growth versus Spontaneous (near-) Surface Alloy Formation: Zn Growth on Au(111)
K.M. Schüttler, J. Bansmann, A.K. Engstfeld, and R.J. Behm
J. Chem. Phys., 152,  124701 (2020)
DOI: 10.1063/1.5145294
Supporting Information

 

 

 

 


Raising the COx Methanation Activity of a Ru/γ-Al2O3 Catalyst by Activated Modification of Metal-Support Interactions
S. Chen, A.M. Abdel-Mageed, M. Dyballa, M. Parlinska-Wojtan, J. Bansmann, S. Pollastri, L. Olivi, G. Aquilanti, and R.J. Behm
Angew. Chem., 22951-22959 (2020)
DOI: 10.1002/ange.202007228
Angew. Chem. Int. Ed., 22763-22770 (2020)
DOI: 10.1002/anie.202007228
Supporting Information

 

 

 

 

 

Effects of SiO2-Doping on High-Surface-Area Ru/TiO2 Catalysts for the Selective CO Methanation
S. Cisneros, S. Chen, T. Diemant, J. Bansmann, A.M. Abdel-Mageed,  M. Goepel, S.E. Olesen, E.S. Welter, M. Parlinska-Wojtan, R. Gläser, I. Chorkendorff, and R.J. Behm
Appl. Catal. B, 282, 119483 (2021)
DOI: 10.1016/j.apcatb.2020.119483
Supporting Information

K.M. Schüttler et al., J. Chem. Phys., 152, 124701

As part of an extensive effort to explore the function of Au/ZnO catalysts in the synthesis of methanol from CO2 and H2 we have systematically investigated the temperature dependent growth, structure formation and surface intermixing of Zn on the herringbone reconstructed Au(111) surface and the thermal stability of the resulting surfaces by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). After Zn deposition at low temperatures (LT), at about 105 K (STM) or below (XPS), we observed nucleation and two-dimensional growth of Zn islands mainly at the elbow sites of the Au(111) herringbone reconstruction. This results in local perturbations of the reconstruction pattern of the Au(111) substrate, which can create additional nucleation sites. XPS data indicate that Zn dissolution into deeper layers is kinetically hindered under these conditions, while local exchange with the Au surface layer, in particular at the elbow sites during nucleation, cannot be excluded. Zn deposition at room temperature (RT), in contrast, results in near-surface alloy formation with a strongly distorted pattern of the herringbone reconstruction, and condensation of the Zn and exchanged Au adatoms at ascending steps, together with some loss of Zn into deeper layers. Upon annealing, Zn atoms diffuse to lower layers and eventually to the Au bulk, and the surface successively regains its original Au(111) herringbone structure, which is almost reached after 500 K annealing. Compared with previous reports on the growth of other metals on Au(111), Zn shows a rather high tendency for intermixing and near-surface alloy formation.

We systematically investigated the temperature dependent growth, structure formation and surface intermixing of Zn on the herringbone reconstructed Au(111) surface and the thermal stability of the resulting surfaces by STM and XPS.

S. Chen et al., Angew. Chem. Int. Ed., in press

Ru/Al2O3 is a highly stable, but less active catalyst for methanation reactions. Here we report an effective approach to significantly improve its performance in the methanation of CO2/H2 mixtures. Highly active and stable Ru/γ-Al2O3 catalysts were prepared by  high-temperature treatment in the reductive reaction gas. Operando / in situ spectroscopy and STEM imaging reveals that the strongly improved activity, by factors of 5 and 14 for CO and CO2 methanation, goes along with a flattening  of the Ru nanoparticles and the formation of highly basic hydroxylated  alumina sites. We propose an activated modification of  the  metal-support interactions (MSIs) as origin of the increased activity, caused by reactive modification of the Al2O3 surface in the reductive atmosphere and increased thermal mobility of the Ru nanoparticles, allowing their transfer to modified surface sites.

We report an effective approach to significantly improve the performance of stable Ru/Al2O3 catalyts in the methanation of CO2/H2 mixtures by temperature treatment in the reductive reaction gas. Operando/in situ spectroscopy and STEM imaging reveals that the strongly improved activity goes along with a flattening of the Ru NPs and the formation of highly basic hydroxylated  alumina sites.

S. Cisneros et al., Appl. Catal. B, 282, 119483

Aiming at a better understanding of the role of electronic / chemical modifications of the support on the performance of high specific surface area Ru/TiO2 catalysts in the selective CO methanation, we prepared and examined four different Ru/TiO2 catalysts with similar Ru loading and similar high specific surface area, but with the support doped with different amounts of Si (0 - 12 wt.% SiO2). Their activity for methane formation exhibits a volcano-shaped dependence on the SiO2 content, with a maximum between 4 and 8 wt.%. The CO adsorption properties showed distinct differences, with the weakest CO adsorption strength for the most active catalysts. Based on the results of a variety of different characterization techniques and pyrrole/pyridine adsorption measurements, the higher activity / lower CO adsorption strength cannot be explained by a single property, such as particle size, but must rather be caused by a complex combination of different effects.

We prepared and examined four Ru/TiO2 catalysts with similar Ru loading and similar high specific surface area, but doped with different amounts of Si (0 - 12 wt.% SiO2). Their activity for methane formation exhibits a volcano-shaped dependence on the SiO2 content, with a maximum between 4 and 8 wt.%.

2019

Morphology-Engineered Highly Active and Stable Ru/TiO2  Catalysts for Selective CO Methanation
S. Chen, A.M. Abdel-Mageed, D. Li, J. Bansmann, S. Cisneros, J. Biskupek, W. Huang, and R.J. Behm
Angew. Chem., 131, 10842-10847 (2019)
Angew. Chem. Int. Ed., 58, 10732-10736 (2019)
DOI: 10.1002/ange.201903882
DOI: 10.1002/anie.201903882
Supporting Information

 

 

 

 

 


Interaction between Li, Ultrathin Adsorbed Ionic Liquid Films and CoO(111) Thin Films: A Model Study of the Solid|Electrolyte Interphase Formation

F. Buchner, K. Forster-Tonigold, J. Kim, J. Bansmann, A. Groß, and R.J. Behm
Chem. Mater., 31, 5537-5549 (2019)
DOI: 10.1021/acs.chemmater.9b01253
Supporting Information

 

 

 

 

 

 

 

Chemical and Electronic Changes of the CeO2 Support during CO Oxidation on Au/CeO2 Catalysts: Time-Resolved Operando XAS at the Ce LIII Edge
J. Bansmann, A.M. Abdel-Mageed, S. Chen, C. Fauth, T. Häring, G. Kučerová, Y. Wang, and R.J. Behm
Catalysts, 9, 785
DOI: 10.3390/catal9100785
Supporting Information

 

 

S. Chen et al., Angew. Chem. Int. Ed., 58, 10732-10736

Ru/TiO2 catalysts exhibit an exceptionally high activity in the selective methanation of CO in CO2 and H2-rich reformates, but suffer from continuous deactivation during reaction. Here we report on a successful attempt to overcome this limitation, fabricating highly active and non-deactivating Ru/TiO2 catalysts by morphology-engineering of the TiO2 support. Using anatase TiO2 nanocrystals with mainly {001}, {100} or {101} facets exposed, we show that after an initial activation period Ru/TiO2-{100} and Ru/TiO2-{101} are very stable, while Ru/TiO2-{001} deactivates continuously. Employing different operando / in situ spectroscopies and ex situ characteri­zations, we show that differences in the catalytic stability are related to differences in the metal–support interactions (MSIs). The stronger MSIs on the defect-rich TiO2-{100} and TiO2-{101} supports not only stabilize flat Ru nanoparticles, while on TiO2-{001} hemispherical particles develop, but also lead to electronic modifications of Ru surface atoms, reflected by a stronger bonding of adsorbed CO on those catalysts than on Ru/TiO2-{001}. Consequences for the performance of these catalysts are discussed.

Ru/TiO2 catalysts exhibit an exceptionally high activity in the selective methanation of CO in CO2 and H2-rich reformates, but suffer from continuous deactivation during reaction. By using anatase TiO2 nanocrystals with mainly {001}, {100} or {101} facets exposed, we show that after an initial activation period Ru/TiO2-{100} and Ru/TiO2-{101} are very stable, while Ru/TiO2-{001} deactivates continuously.

F. Buchner et al., Chem Mater., 31, 5537-5549

Aiming at a molecular level understanding of the processes at the electrode|electrolyte interface (EEI), we investigated the interaction between the battery-relevant Ionic Liquid (IL) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP]+[TFSI]‒), Li and CoO(111) thin films on Ru(0001) as a model study of the solid|electrolyte interphase (SEI) in Li-ion batteries (LIBs). Employing mainly angle-dependent X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM), in combination with dispersion-corrected density functional calculations (DFT-D) for characterization of the CoO(111) surface, we found that vapor deposition of metallic Li on CoO(111) at 300 K results in the conversion of Co2+ to Co0, together with the formation of Li2O and adsorbed surface Li2O2. The conversion starts in the near surface region (1-2 nm) and proceeds in the extended surface region (6-8 nm). If the surface is precovered by molecularly adsorbed anion-cation pairs of [BMP][TFSI] (solvent / electrolyte), stepwise postdeposition of small amounts of Li results in gradual decomposition of [TFSI] and [BMP] (= SEI formation ), forming products such as Li3N, Li2S, LiF, LiCyHyNz and other Li-bound fragments of the anion. For higher amounts of Li deposition, relative to the IL precoverage, IL decomposition is followed by conversion of CoO(111). Hence, the SEI resulting from IL decomposition is permeable for Li, which is essential for the storage of Li in the CoO(111) anode. This study demonstrates the potential of model studies for a molecular scale understanding of the initial stages of SEI formation at the EEI, and its role in Li storage in a CoO(111) model anode.

We investigated the interaction between the battery-relevant Ionic Liquid  ([BMP]+[TFSI]‒), Li and CoO(111) thin films on Ru(0001) as a model study of the solid|electrolyte interphase (SEI) in Li-ion batteries.  Deposition of Li on CoO(111) at 300 K results in the conversion of Co2+ to Co0, postdeposition of Li on a IL precovered surface results in gradual decomposition of [TFSI] and [BMP].

J. Bansmann et al., Catalysts, 9, 785

While being highly active for the CO oxidation reaction already at low temperatures, Au/CeO2 catalysts suffer from continuous deactivation with time on stream, with the activity and deactivation depending on the initial catalyst activation procedure. In previous X-ray absorption measurements at the Au LIII edge, which focused on changes in the electronic and geometric changes of Au, we found a modest increase of the Au particle size during reaction, with the Au nanoparticles (NPs) present in a dominantly metallic state during reaction, regardless of the pretreatment. Here we aim at expanding on these insights by examining the changes in electronic and chemical composition of the CeO2 support induced by different pretreatment procedures and during subsequent CO oxidation at 80°C, by following changes at the Ce LIII near edge region in time-resolved operando X-ray absorption measurements. The results indicate a strong dependence of the initial concentration of Ce3+ ions on the pretreatment, while during subsequent reaction this rapidly approaches a steady-state value which depends on the oxidative/reductive character of the reaction gas mixture, but is largely independent of the pretreatment. These results are discussed and related to earlier finding on the electronic properties of Au nanoparticles under identical reaction conditions.

Au/CeO2 catalysts, being highly active for the CO oxidation reaction already at low temperatures, suffer from continuous deactivation with time on stream. Here we aim at the changes in electronic and chemical composition of the CeO2 support induced by different pretreatment procedures and during subsequent CO oxidation at 80°C, by following changes at the Ce LIII near edge region in time-resolved operando X-ray absorption measurements.

2018

Structure Formation and Surface Chemistry of Ionic Liquids on Model Electrode Surfaces ‒ Model Studies for the Electrode | Electrolyte Interface in Li-ion Batteries
F. Buchner, B. Uhl, K. Forster-Tonigold, H. Farkhondeh, J. Bansmann, A. Groß, and R.J. Behm
J. Chem. Phys., 148, 193821 (2018)
DOI: 10.1063/1.5012878
Supporting Information

 

 

 

 

 


Experimental and Computational Study on the Interaction of an Ionic Liquid Monolayer with Lithium on Pristine and Lithiated Graphite
F. Buchner, K. Forster-Tonigold, J. Kim, C. Adler, J. Bansmann, A. Groß, and R.J. Behm
J. Phys. Chem. C, 122, 18968−18981 (2018)
DOI: 10.1021/acs.jpcc.8b04660
Supporting Information

 

 

F. Buchner et al., J. Chem. Phys., 148, 193821

Ionic liquids (ILs) are considered as attractive electrolyte solvents in modern battery concepts such as Li-ion batteries. Here we present a comprehensive review of results of previous model studies on the interaction of the battery relevant IL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP]+[TFSI]) with a series of structurally and chemically well-defined model electrode surfaces, which are increasingly complex and relevant for battery applications (Ag(111), Au(111), Cu(111), pristine and lithiated HOPG, rutile TiO2(110)). Combining surface science techniques such as high resolution scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS) for characterizing surface structure and chemical composition in deposited (sub-)monolayer adlayers with dispersion corrected density functional theory (DFT-D) based calculations, this work aims at a molecular scale understanding of the fundamental processes at the electrode|electrolyte interface, which are crucial for the development of the so-called solid electrolyte interphase (SEI) layer in batteries. Performed under idealized conditions, in an ultrahigh vacuum (UHV) environment, these model studies provide detailed insights on the structure formation in the adlayer, the substrate - adsorbate and adsorbate – adsorbate interactions responsible for this, and the tendency for chemically induced decomposition of the IL. To mimic the situation in an electrolyte, we also investigated the interaction of adsorbed IL (sub-)monolayers with coadsorbed lithium. Even at 80 K, postdeposited Li is found to react with the IL, leading to decomposition products such as LiF, Li3N, Li2S, LixSOy, Li2O etc.. In the absence of a [BMP]+[TFSI]- adlayer, it tends to adsorb, dissolve or intercalate into the substrate (metals, HOPG) or to react with the substrate (TiO2) above a critical temperature, forming LiOx and Ti3+ species in the latter case. Finally, the formation of stable decomposition products was found to sensitively change the equilibrium between surface Li and Li+ intercalated in the bulk, leading to a deintercalation from lithiated HOPG in the presence of an adsorbed IL adlayer at > 230 K. Overall, these results provide detailed insights into the surface chemistry at the solid|electrolyte interface and the initial stages of SEI formation at electrode surfaces in the absence of an applied potential, which is essential for the further improvement of future Li-ion batteries.

Here we present a comprehensive review of results of previous model studies on the interaction of the battery relevant IL [BMP]+[TFSI] with a series of structurally and chemically well-defined model electrode surfaces, which are increasingly complex and relevant for battery applications (Ag(111), Au(111), Cu(111), pristine and lithiated HOPG, rutile TiO2(110)).

F. Buchner et al., J. Phys. Chem C, 122, 18968−18981

We report results of a combined experimental and computational model study on the interaction of the battery-relevant Ionic Liquid (IL) 1-butyl-1-methylpyrrolidinium bis(tri­fluoromethylsulfonyl)imide ([BMP]+[TFSI]‒) with Li on pristine highly oriented pyrolytic graphite (HOPG), which aims at a molecular/atomic level understanding of the processes at the electrode|electrolyte interface of Li-ion batteries. Employing mainly X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS) as well as dispersion-corrected density functional calculations (DFT-D), we find intact anion-cation pairs for adsorbed [BMP]+[TFSI]‒ (sub-)monolayers on HOPG at 300 K, and also on lithiated HOPG at 80 K, i.e., under conditions where the mobility of Liδ+ in the bulk is low. Vapor deposition of [BMP]+[TFSI]- on lithiated HOPG at 300 K results in rapid accumulation of Lid at the surface or in the surface region, indicating that de-intercalation is activated under these conditions. This is explained by a dynamic equilibrium between bulk Li+ and surface Liδ+, which is established independent of whether Li is deposited as metallic Li0 from the vacuum side or segregates as Li+ from the bulk of lithiated HOPG to the surface, and which is shifted to the side of surface Liδ+ by stabilization of these species. Stabilization occurs either by formation of stable Li-containing surface compounds by reactive decomposition mainly of the [TFSI]‒ anions (Li3N, Li2S, LiF, etc.), or by interaction of partially charged Liδ+ species with [TFSI]‒ anions in the adlayer. DFT-D calculations reveal that a possible initial step in the reactive decomposition is the transfer of electrons from the HOPG surface covered with Liδ+ into the lowest unoccupied molecular orbital of [TFSI]‒, resulting in elongation and cleavage of the S‒N bond and finally insertion of Li into it. Alternatively, stabilization of Liδ+ is possible by formation of a polar bond with the oxygen atoms of [TFSI]‒ within the IL adlayer. The resulting calculated work function decrease ΔΦ  with respect to that of the bare graphite(0001) surface is in excellent agreement with experimental observations. The interaction of [BMP]+[TFSI]‒ and Li at the HOPG interface is considered as the initial stage of the solid|electrolyte interphase formation at the electrode|electrolyte interface in Li-ion batteries.

We report results of a combined experimental and computational model study on the interaction of  Ionic Liquid (IL)  [BMP]+[TFSI] with Li on (HOPG). We  find  intact  anion-cation  pairs  for  adsorbed IL - monolayers on HOPG at 300 K, and also on lithiated HOPG at 80 K. Vapor deposition of IL on lithiated HOPG (300 K) results in rapid accumulation of Liδ+ at the surface indicating  that  de-intercalation is activated under these conditions.

2017

In-Flight and Postdeposition Manipulation of Mass-Filtered Nanoparticles under Soft-Landing Conditions
J. Bansmann, A. Kleibert, H. Bettermann, and M. Getzlaff
in: Gas-Phase Synthesis of Nanoparticles, ed. Y. Huttel
Wiley-VCH Verlag, Weinheim (2017)
DOI: 10.1002/9783527698417.ch17

 

 

 

 

 

 

 

 

 

 

Active Au species during the Low-Temperature Water Gas Shift Reaction on Au/CeO2: A Time resolved Operando XAFS and DRIFTS Study
A.M. Abdel-Mageed, G. Kučerová, J. Bansmann, and R.J. Behm
ACS Catal.
, 7, 6471–6484 (2017)
DOI: 10.1021/acscatal.7b01563
Supporting Information

 

 

 

 

 

 

Influence of re-activation and ongoing CO oxidation reaction on the chemical and electronic properties of Au on a Au/CeO2 catalyst: A XANES study at the Au LIII edge
J. Bansmann, G. Kučerová, A.M. Abdel-Mageed, A. Abd El-Moemen, and R.J. Behm
J. Electron. Spectrosc. Relat. Phenom.
, 220, 86-90 (2017)
DOI: 10.1016/j.elspec.2017.01.002
Supporting Information

 

 

 

 

 

 

Intercalation and Deintercalation of Lithium at the Ionic Liquid | Graphite(0001) Interface
F. Buchner, J. Kim, C. Adler, M. Bozorgchenani, J. Bansmann, and R.J. Behm
J. Phys. Chem. Lett., 8, 5804-5809 (2017)
DOI: 10.1021/acs.jpclett.7b02530

Bookchapter in Gas-Phase Synthesis of Nanoparticles

The formation of clusters and nanoparticles in the gas phase under non-equilibrium conditions can be used to create objects with unique physical and chemical properties. In order to conserve those properties during deposition and to select only particles with a certain number of atoms and specific properties, soft-landing, selection of particles within a well-defined mass or size regime and in-flight modification by thermal annealing, and coating processes are being used. The properties of the cluster-on-surface systems can be significantly altered by varying the kinetic energy of the particles as well as the substrate temperature or by preparation of rare gas buffer layers.

In-Flight and Postdeposition Manipulation of Mass-Filtered Nanoparticles under Soft-Landing Conditions

J. Bansmann et al., in: Gas-Phase Synthesis of Nanoparticles, ed. Y. Huttel,
Wiley-VCH Verlag, Weinheim (2017)

 

A.M. Abdel-Mageed et al., ACS Catalysis, 7, 6471–6484

 Operando XAS measurements in the near (XANES) and the extended (EXAFS) Au LIII edge as well as in situ diffuse reflectance FTIR (DRIFTS) spectroscopy were employed in combination with kinetic measurements in a further attempt to identify the nature of the active Au species responsible for the high activity of Au/CeO2 catalyst in the low-temperature water gas shift (LT-WGS) reaction. The changes in the reaction behavior during the LT-WGS were followed at 180° C for different initial states of the catalyst, prepared by either reducing or oxidizing pretreatments at different temperatures. Findings from kinetic and deactivation measurements were correlated with experimental data on the Au particle size, the Au oxidation state, and the CO-Au adsorption properties directly after different pretreatments and during the subsequent LT-WGS reaction obtained by operando/in situ spectroscopy measurements. The combined experimental results show that the use of different pretreatments can significantly influence the electronic state of the Au species (Au δ, Au0, Au δ+). Exposure to the reaction atmosphere under the present reaction conditions, however, results in the rapid formation of extremely small, (sub)nanometer-sized Au0 nanoparticles, which are the dominant Au species and responsible for the high WGS activity. Small amounts of oxidic gold species (Au3+) persisting during reaction after the strongly oxidative O400 pretreatment, in the few percent range, are too little to be responsible for the catalytic activity of that catalyst and changes therein with time on stream.

XAS measurements at the Au LIII edge and in-situ DRIFTS / kinetic measurements were employed to identify the nature of the active Au species responsible for the high activity of Au/CeO2 catalyst in the low-temp. water gas shift reaction. Exposure to reaction atmosphere results in the rapid formation of extremely small  Au0 nanoparticles.

J. Bansmann et al., J. Electron Spectrosc. Relat. Phenom., 220, 86-90

The influence of oxidative / reductive pretreatments, oxidative re-activation and ongoing CO oxidation on the chemical / electronic properties of a 4.5 wt.% Au/CeO2 catalyst was investi­gated by in operando X-ray absorption spectroscopy at the Au LIII edge. Experimental data on the electronic structure and the size of the Au nanoparticles are correlated with findings from kinetic and deactivation measurements. The results of this study show that oxidative re-activation as well as reductive and oxidative pretreatment significantly affect the Au electronic structure and, in consequence, the catalytic properties. Independent of the type of the treatment, however, the Au nanoparticles rapidly reach a metallic state during reaction, both after oxidative pretreatment and after oxidative re-activation, and can therefore not be responsible for the long-term deactivation of the catalyst. Correlations between electronic / chemical structure, evaluated in a semi-quantitative model, and the catalytic performance are discussed.

The influence of pretreatments, re-activation and ongoing CO oxidation on the chemical / electronic properties of a Au/CeO2 catalyst was investi­gated by in operando X-ray absorption spectroscopy at the Au LIII edge. The results show that the re-activation and  pretreatments significantly affect the Au electronic structure and, in consequence, the catalytic properties.

F. Buchner et al., J. Phys. Chem. Lett., 8, 5804-5809

The intercalation and deintercalation of lithium (Li) into graphite(0001), which is a highly important process in Li-ion batteries, was investigated under ultrahigh vacuum conditions as a function of temperature, employing X-ray and ultraviolet photoelectron spectroscopy. Both the up-shifts of the core level binding energy and the lowering of the work function DF reveal that heating of a monolayer of the battery‒relevant ionic liquid (IL) 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP]+[TFSI]-) adsorbed on lithiated graphite at 80 K to > 230 K facilitates an accumulation of partially charged Liδ+ atoms at the IL|graphite(0001) interface. This is accompanied by a partial IL decomposition, which is associated with the initial stages of the chemical formation of the solid|electrolyte interphase.

The intercalation and deintercalation of Li into graphite(0001), a highly important process in Li-ion batteries, was investigated using XPS and UPS. Both the upshifts of the core level binding energy and the lowering of the work function reveal that heating of a monolayer of the ionic liquid (IL) [BMP]+[TFSI]- adsorbed on lithiated graphite at 80K to > 230K facilitates an accumulation of partially charged Liδ+ atoms at the IL|graphite(0001) interface.

2016

Geometric and electronic structure of Au on Au/CeO2 catalysts during the CO oxidation: Deactivation by reaction induced particle growth
Ali M. Abdel-Mageed, G. Kučerová, A. Abd El-Moemen, J. Bansmann, D. Widmann, and R.J. Behm
J. Phys.: Conf. Series, 712, 012044 (2016)
DOI: 10.1088/1742-6596/712/1/012044
Supporting Information

Article PDF (Open Access: CC BY-3.0)

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

 

 

 

Structure Formation and Thermal Stability of Mono- and Multilayers of Ethylene Carbonate on Cu(111) ‒ A Model Study for the Electrode|Electrolyte Interface
M. Bozorgchenani, M. Naderian, H. Farhkondeh, J. Schnaidt, B. Uhl, J. Bansmann, A. Groß, R.J. Behm, and Florian Buchner
J. Phys. Chem. C, 120, 16791-16803 (2016)
DOI: 10.1021/acs.jpcc.6b05012

 

 

 

 

 

Deactivation of Au/CeO2 catalysts in the CO oxidation reaction: Influence of pretreatment and reaction conditions
A. Abd El-Moemen, A.M. Abdel-Mageed, J. Bansmann, M. Parlinska-Wojtan, R.J. Behm, and G. Kučerová
J. Catal., 341, 160–179 (2016)
DOI: 10.1016/j.jcat.2016.07.005
Supporting Information

 

 

 

 

 

 

 

Wie lange halten Edelstahlklebungen
C. Dietrich, J. Bayer, J. Bansmann, T. Diemant, and R.J. Behm
Adhäsion, KLEBEN+DICHTEN, 60, 44-49 (2016)
DOI: 10.1007/s35145-016-0037-8
The durability of stainless steel bondings
Adhesion, Adhesives+Sealants, 13, 26–31 (2016)
DOI: 10.1007/s35784-016-0036-z

A.M. Abdel-Mageed et al., J. Phys.: Conf. Series, 712, 012044

Changes of the geometric and electronic structure of gold on Au/CeO2 catalysts induced by different pre-treatments (oxidative and reductive) and by the CO oxidation reaction at 80°C were followed by operando XANES / EXAFS measurements. The results showed that i) oxidative pre-treatment (O2) leads to larger Au nanoparticles than reductive pre-treatment (CO), that ii) Au is predominantly metallic during CO oxidation, irrespective of the preceding pre-treatment, and that iii) there is a reaction induced Au particle growth. Correlations with the activity of the respective catalysts and its temporal evolution give insights into the origin of deactivation of these catalysts under reaction conditions, in particular on reaction induced changes in the Au particle size.

Geometric and electronic structure of Au on Au/CeO2 catalysts during the CO oxidation: Deactivation by reaction induced particle growth

Operando XANES/EXAFS on Au/CeO2 catalysts showed:

  • larger Au NPs after oxidative than reductive pre-treatment
  • Au metallic during CO oxidation
  • reaction induced Au NP growth.

M. Bozorgchenani et al., J. Phys. Chem. C, 120, 16791-16803

We aim at a molecular scale understanding of the interactions and structure formation at the electrode|electrolyte interface (EEI) in Li-ion batteries. The interaction of the key electrolyte component ethylene carbonate (EC) with Cu(111) was investigated under UHV conditions using STM, XPS, FTIRS, and dispersion-corrected DFT-D calculations. After vapor deposition on Cu(111) at 80 K, STM measurements reveal a well-ordered commensurate superstructure, in which EC molecules assume different configurations and whose total adsorption energy is mainly governed by van der Waals interactions. Between 150–220 K, competing desorption and decomposition result in distinct changes of the adlayer composition. Similar heating of an EC multilayer film to RT results in a surface covered with adsorbed, carbon-containing decomposition products.

The interaction of ethylene carbonate (EC) with Cu(111) was investigated using STM, XPS, FTIRS, and dispersion-corrected DFT-D calculations. Between 150–220 K, competing desorption and decomposition result in distinct changes of the adlayer composition. Heating to RT results in a surface covered with carbon-containing decomposition products.

A. Abd El-Moemen et al., J. Catal., 341, 160-179

The influence of the pretreatment on the activity and deactivation behavior of a high surface area 4.5 wt.% Au/CeO2 catalyst during low temperature CO oxidation reaction (Treact = 80 °C) was studied in a multi-technique approach. Findings from kinetic and deactivation measurements are correlated with the Au particle size, Au and Ce oxidation state, and on the nature of adsorbed species after the different pretreatments and during/after subsequent reaction, obtained by operando XAS and in situ IR spectroscopy, as well as ex situ XPS, XRD and HRTEM. These data revealed that the pretreatment significantly affects catalyst structure, surface composition and activity in the initial stages of the reaction. During reaction, however, the catalyst surface composition approaches a dynamic equilibrium state, which is largely reached already after 10 min time on stream and which is independent of the pretreatment. Consequently, under present reaction conditions, longer-term deactivation is not dominated by the buildup of site blocking adsorbed species such as surface carbonates, but by slow processes such as reduction/re-oxidation of the bulk support during the reaction in combination with a modest irreversible Au NP growth.

The influence of pretreatments on the activity / deactivation behavior of Au/CeO2 catalysts during low temperature CO oxidation was studied operando XAS and in situ IR spectroscopy. During reaction, the catalyst surface composition approaches after 10 min time on stream a dynamic equilibrium state. Longer-term deactivation is dominated by slow processes (reduction/re-oxidation of support) in combination with Au NP growth.

2015

Reactive interaction of (sub)-monolayers and multilayers of the ionic liquid [BMP][TFSA] with co-adsorbed lithium on Cu(111)
F. Buchner, M. Bozorgchenani, B. Uhl, H. Farkhondeh, J. Bansmann, and R.J. Behm
J. Phys. Chem. C, 119, 16649-16659 (2015)
DOI: 10.1021/acs.jpcc.5b03765
Supporting Information

F. Buchner et al., J. Phys. Chem. C, 119, 16649-16659

 The ionic liquid (IL) 1-butyl-1-methylpyrrolidinium bis(trifluoro-methylsulfonyl)imide [BMP][TFSA] is a promising candidate for improved next-generation rechargeable lithium − ion batteries. We here report results of a model study of the reactive interaction of (sub-)monolayers and multilayers of [BMP][TFSA] with lithium (Li) on Cu(111), employing scanning tunnelling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIRS) under ultrahigh vacuum (UHV) conditions. Upon post-deposition of Li on [BMP][TFSA] multilayers at 80 K, we identi fi ed changes in the chemical state of the [TFSA] anion and the [BMP] cation as well as in the IR absorption bands related to the anion. These changes are most likely due to the decomposition of the IL adlayer into a variety of products like LiF, Li2S, and Li2O upon anion decomposition and LiN3, LiCxHyN, and LixCHy upon cation decomposition, where the latter includes cracking of the pyrrolidinium ring. Deposition of Li on [BMP][TFSA] (sub-)monolayer-covered surfaces led to similar decomposition patterns, and the same was also observed for the reverse deposition order. The addition of the corresponding amounts of Li to a [BMP][TFSA] adlayer resulted in distinct changes in the STM images, which must be due to the surface reaction. After annealing to 300 K, the core-level peaks of the cation lose most of their peak area. Upon further heating to 450 K, the anion is nearly completely decomposed, resulting in LiF and Li2S decomposition products that dominate the interface.

We report on the reactive interaction of [BMP][TFSA] with Li on Cu(111) using STM, XPS, and FTIRS. Depositing Li at 80 K results in a decomposition of the IL adlayer into a variety of products. Heating to 450 K leads to the decomposition of the anion in mainly LiF and Li2S as products.

2014

Direct observation of magnetic metastability in individual iron nanoparticles
A. Balan, P.M. Derlet, A. Fraile Rodríguez, J. Bansmann, R. Yanes, U. Nowak, A. Kleibert, and F. Nolting
Phys. Rev. Lett., 112, 107201 (2014)
DOI: 10.1103/PhysRevLett.112.107201
Supplemental Material

 

 

 

 

 

 

 

Novel N, C doped Ti(IV)-oxides as Pt-free catalysts for the O2 reduction reaction
C. Gebauer, J. Fischer, M. Wassner, T. Diemant, J. Bansmann, N. Hüsing, and R.J. Behm
Electrochim. Acta, 146, 335-345 (2014)
DOI: 10.1016/j.electacta.2014.08.056
Supporting Information

 

 

 

 

 

 

 

 

 

Interaction of coadsorbed CO and deuterium on a bimetallic, Pt monolayer island modified Ru(0001) surface
H. Hartmann, J. Bansmann, T. Diemant, and R.J. Behm
J. Phys. Chem. C, 118, 28948–28958 (2014)
DOI: 10.1021/jp504409s
This article is part of the John C. Hemminger Festschrift special issue.

A. Balan et al., Phys. Rev. Lett., 112, 107201

X-ray photoemission electron microscopy combined with x-ray magnetic circular dichroism is used to study the magnetic properties of individual iron nanoparticles with sizes ranging from 20 down to 8 nm. While the magnetocrystalline anisotropy of bulk iron suggests superparamagnetic behavior in this size range, ferromagnetically blocked particles are also found at all sizes. Spontaneous transitions from the blocked state to the superparamagnetic state are observed in single particles and suggest that the enhanced magnetic energy barriers in the ferromagnetic particles are due to metastable, structurally excited states with unexpected life times.

X-ray photoemission electron microscopy with XMCD is used to study the magnetic properties of individual Fe NPs. Spontaneous transitions from ferromagnetically blocked to superparamagnetic states are observed in single particles.

C. Gebauer et al., Electrochim. Acta, 146, 335-345

The potential of novel, carbon and nitrogen doped Ti-oxides for application as Pt-free catalyst for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cell cathodes was systematically investigated in model studies under well defined reaction conditions. Ti oxide was prepared by a sol-gel process; doping of titania with N and C was performed via reactive incorporation during the sol-gel processing and the subsequent calcination step, using the Ti-alkoxide precursor and urea, which is added during the sol-gel synthesis, as carbon source and urea also as nitrogen source. Optimizing the chemical composition of the catalyst was performed by varying the calcination temperature or the amount of urea. Characterization of the resulting material by X-ray photoelectron spectroscopy (XPS) identified Ti–O–C, Ti–O–N and O–Ti–N building blocks, providing clear evidence for the incorporation of N and C into the TiOx lattice; the concentrations of the species depend on the calcination temperature and on the amount of urea added. Doping with nitrogen was found to significantly improve the ORR performance compared to non-doped TiOx, with the extent depending on the calcination temperature and the N : Ti ratio. Correlations between ORR activity and the lattice composition and crystallinity are discussed. Finally, the activity for oxidation/reduction of the ORR intermediate hydrogen peroxide was tested, yielding similar trends but less pronounced effects than obtained for the ORR.

The potential of novel C- and N- doped Ti-oxides for application as Pt-free catalyst in polymer electrolyte fuel cell cathodes was investigated in model studies.  Doping with nitrogen improves the ORR performance compared to non-doped TiOx.

H. Hartmann et al., J. Phys. Chem. C, 118, 28948–28958

We have investigated the coadsorption of CO and deuterium on structurally well-defined bimetallic, Pt monolayer island modi fi ed Ru(0001) surfaces, focusing on the interactions between the coadsorbed species and their impact on the adsorption and desorption characteristics. Temperature-programmed desorption (TPD) and infrared reflection absorption spectroscopy (IRRAS) measurements after adsorption at 90 K reveal considerable differences between adlayers formed by preadsorption of deuterium and subsequent saturation by CO or in the reverse way. We demonstrate that these differences are caused by the limited mobility of adsorbed CO at low temperatures and spillover of CO ad from Pt monolayer areas to Ru(0001) areas upon heating, e.g., during a TPD measurement. The interplay between energetics, including the presence of weakly adsorbing Pt monolayer sites and strongly adsorbing Ru(0001) sites as well as interactions between coadsorbed species, and the onset of CO ad spillover on the adsorption and desorption behavior of deuterium, which results in complex deuterium desorption spectra, are illustrated and discussed.

The coadsorption of CO and D2 on Pt islands on Ru(0001) surfaces was studied using TPD and IRRAS at 90 K.  The interplay between energetics (weakly adsorbing Pt ML and strongly adsorbing Ru(0001) sites), interaction between adsorbates, and the onset of COad spillover results in complex D2 TPD spectra.

2012

Interaction of CO with structurally well defined monolayer PtAu/Pt(111)
M. Eyrich, T. Diemant, H. Hartmann, J. Bansmann, and R.J. Behm
J. Phys. Chem. C, 116, 11154-11165 (2012)
DOI: 10.1021/jp302469c

 

 

 

 

 

 

 

 

Interaction of CO and deuterium with bimetallic, monolayerPt island / film covered Ru(0001) surfaces
H. Hartmann, T. Diemant, J. Bansmann, and R.J. Behm
Phys. Chem. Chem. Phys., 14, 10919-10934 (2012)
DOI: 10.1039/c2cp41434a

 

 

 

 

 

 

 

The adsorption of oxygen and coadsorption of CO and oxygen on structurally well defined PdAg/Pd(111) surface alloys
A.P. Farkas, T. Diemant, J. Bansmann, and R.J. Behm
Chem. Phys. Chem., 13, 3516-3525 (2012)
DOI: 10.1002/cphc.201200477

M. Eyrich et al., J. Phys. Chem. C, 116, 11154-11165

The adsorption properties of structurally well-defined bimetallic PtAu/Pt(111) monolayer surface alloys, with known lateral distribution of the respective surface species and varied Au surface contents, were studied by temperature-programmed desorption (TPD) and infrared reflection–absorption spectroscopy (IRAS), using CO as probe molecule. The surface composition and the lateral distribution of surface atoms in the PtAu/Pt(111) surface alloys were previously determined by high-resolution scanning tunneling microscopy (STM) [Bergbreiter, A.; et al. ChemPhysChem 2010, 11, 1505], showing a tendency for lateral segregation of both metals in the surface layer. CO adsorption on these surfaces is dominated by adsorption on Pt on-top sites; the fraction of bridge-bonded COad decays rapidly with increasing Au surface content and is completely absent for surfaces with 35% and more surface Au content. Adsorption on Au sites is negligible at 100 K. The roles of electronic ligand and strain effects and of geometric ensemble effects on the CO adsorption properties, including energetics, maximum COad coverage, vibrational properties, and adsorption kinetics, are mapped out and discussed. The results are compared with CO adsorption on comparable surface alloys such as PtAg/Pt(111), PdAu/Pd(111), and PdAg/Pd(111) as well as on the inverse system PtAu/Au(111).

The adsorption properties of PtAu/Pt(111) surface alloys with known lateral distribution of the respective surface species were studied by TPD and IRAS, using CO as probe molecule.  The roles of electronic ligand and strain effects and of geometric ensemble effects on the CO adsorption properties are discussed.

H. Hartmann et al., Phys. Chem. Chem. Phys., 14, 10919-10934

The adsorption properties of structurally well defined bimetallic Pt/Ru(0001) surfaces, consisting of a Ru(0001) substrate partly or fully covered by monolayer Pt islands or a monolayer Pt film, were studied by temperature programmed desorption (TPD) using CO and deuterium as probe molecules. Additionally, the adsorption of CO was investigated by infrared reflection absorption spectroscopy (IRAS). The presence of the pseudomorphic platinum islands or monolayer film leads to considerable modifications of the adsorption properties for both adsorbates, both on the Pt covered and, to a smaller extent, on the bare Ru part of the surfaces. In addition to distinct weakly bound adspecies, which are adsorbed on the monolayer Pt islands, we find unique contributions from island edge desorption, from spill-over processes during the desorption run, and a general down-shift of the peak related to desorption from Pt-free Ru(0001) areas with increasing Pt coverage. These effects, which we consider as characteristic for adsorption on bimetallic surfaces with large contiguous areas of the respective types, are discussed in detail.

The adsorption properties of Pt/Ru(0001) surfaces were studied by TPD using CO and D2 as probe molecules and IR spectroscopy. Pt islands lead to modifications of the adsorption properties for both adsorbates. In addition, we find spill-over processes during TPD and a down-shift of the peak related to desorption from Pt-free Ru(0001) areas with increasing Pt coverage.

A.P. Farkas et al., Chem. Phys.Chem., 13, 3516-3525

The dissociative interaction of oxygen with structurally well‐defined monolayer PdxAg1−x/Pd(111) surface alloys of different compositions, with well‐known distributions of the respective surface atoms (A. K. Engstfeld et al., Phys. Chem. Chem. Phys. 2012, 14, 10754–10761), and the coadsorption of/reaction with CO on oxygen pre‐covered surfaces were studied by high‐resolution electron energy loss spectroscopy (HREELS) and temperature‐programmed desorption/reaction spectroscopy (TPD/TPR). The impact of geometric ensemble effects as well as electronic ligand and strain effects on the adsorption and reaction behaviour of the respective species on the bimetallic surfaces is elucidated and compared with related systems such as CO adsorption on similar surfaces and oxygen adsorption on a Pd67Ag33(111) bulk alloy surface. The data show a clear dominance of ensemble effects on the oxygen adsorption and CO coadsorption behaviour, with oxygen adsorption limited to threefold‐hollow sites on Pd3 sites, while the combined electronic effects, as evident from modifications in the adsorption and reaction characteristics on the Pd sites, are small.

The dissociative interaction of O2 on PdxAg1−x/Pd(111) surface alloys and the coadsorption of/reaction with CO on oxygen pre-covered surfaces were studied by HREELS and TPD/TPR. The impact of geometric ensemble effects, electronic ligand and strain effects  is elucidated. The data show a dominance of ensemble effects on the oxygen adsorption and CO coadsorption, with oxygen adsorption limited to threefold-hollow sites on Pd3 sites, while the combined electronic effects are small.

2011

    A. Kleibert, W. Rosellen, M. Getzlaff, and J. Bansmann
    Structure, morphology, and magnetic properties of Fe nanoparticles deposited onto single-crystalline surfaces
    Beilstein Journal of Nanotochnology, 2, 47-56 (2011)
    DOI: 10.3762/bjnano.2.6

    Y. Ma, T. Diemant, J. Bansmann, and R.J. Behm
    The interaction of CO with PdAg/Pd(111) surface alloys – A case study of ensemble effects on a bimetallic surface
    Phys. Chem. Chem. Phys., 13, 10741-10754 (2011)
    DOI:10.1039/c1cp00009h

    M. Roos, D. Böcking, K. Offeh Gyima, G. Kucerova, J. Bansmann, J. Biskupek, U. Kaiser, N. Hüsing, and R.J. Behm
    Nanostructured, Mesoporous Au/TiO2 Model Catalysts – Structure, Stability and Catalytic Properties
    Beilstein Journal of Nanotechnology, 2, 593-606 (2011)
    DOI: 10.3762/bjnano.2.63

2010

    A. Kleibert, F. Bulut, W. Rosellen, K.H. Meiwes-Broer, J. Bansmann, and M. Getzlaff
    Supported and embedded Fe nanoparticles: influence of the environment on shape and intreface contribution to the magnetic anisotropy
    J. Phys.: Conf. Series, 211, 012017 (2010)
    DOI: 10.1088/1742-6596/211/1/012017 pdf: JPhysConfSer211

     

    A. Fraile Rodriguez, A. Kleibert, J. Bansmann, A. Voitkans, L.J. Heyderman, and F. Nolting
    Size-dependent spin structures in iron nanoparticles
    Phys. Rev. Lett., 104, 127201 (2010)
    DOI: 10.1103/PhysRevLett.104.127201 pdf: PRL104p127201

     

    J. Bansmann, A. Kleibert, M. Getzlaff, A. Fraile Rodriguez, F. Nolting, C. Boeglin, and K.-H. Meiwes-Broer
    Magnetism of 3d transition metal nanoparticles on surfaces probed with synchrotron radiation - from ensembles towards individual objects
    Physica Status Solidi B, 247, 1152-1160 (2010)
    DOI: 10.1002/pssb.200945516

     

    W. Rosellen, C. Kleinhans, V. Hückelkamp, F. Bulut, A. Kleibert, J. Bansmann, and M. Getzlaff
    Influence of substrate and temperature on the shape of deposited Fe, Co and FeCo nanoparticles
    Physica Status Solidi B
    , 247, 1032-1038 (2010)
    DOI: 10.1002/pssb.200945569

     

    S. Valencia, A. Kleibert, A. Gaupp, J. Rusz, D. Legut, J. Bansmann, W. Gudat, and P.M. Oppeneer
    Quadratic x-ray magneto-optical effect in near-normal incidence reflection in a near-normal-incidence configuration at the M edges of 3d-transition metals
    Phys. Rev. Lett., 104, 187401 (2010)
    DOI: 10.1103/PhysRevLett.104.187401

     

    T. Diemant, J. Bansmann, and H. Rauscher
    Coadsorption of hydrogen and CO on hydrogen
    pre-covered PtRu/Ru(0001) surface alloys

    Chem. Phys. Chem., 11, 1482-1490 (2010)
    DOI: 10.1002/cphc.200900839

     

    M. Eyrich, S. Kielbassa, T. Diemant, J. Biskupek, U. Kaiser, U. Wiedwald, P. Ziemann, and J. Bansmann
    Planar Au/TiO2 model catalysts: fabrication, characterization and catalytic activity
    Chem. Phys. Chem., 11, 1430-1437 (2010)
    DOI:10.1002/cphc.200900942

     

    L. Artiglia, T. Diemant, H. Hartmann, J. Bansmann, R.J. Behm, L. Gavioli, E. Cavaliere, and G. Granozzi
    Stability and chemisorption properties of ultrathin TiOx/Pt(111) films and Au/TiOx/Pt(111) model catalysts in reactive atmospheres
    Phys. Chem. Chem. Phys., 12, 6864-6874 (2010)
    DOI: 10.1039/c000884b

     

    T. Diemant, H. Rauscher, J. Bansmann, and R. J. Behm
    Coadsorption of hydrogen and CO on well-defined Pt35Ru65/Ru(0001) surface alloys – Site specificity versus adsorbate-adsorbate interactions
    Phys. Chem. Chem. Phys., 12, 9801-9810 (2010)
    DOI: 10.1039/c003368E

     

    M. Roos, J. Bansmann, D. Zhang, O. Deutschmann, and R.J. Behm
    Product gas evolution above planar microstructured model catalysts – A combined scanning mass spectrometry, Monte Carlo and CFD study
    J. Chem. Phys., 133, 094504 (2010)
    DOI: 10.1063/1.3475518 pdf:

     

    T. Diemant, A. Bergbreiter, J. Bansmann, H.E. Hoster, and R.J. Behm
    From adlayer islands to surface alloy – Influence of structural changes on the chemical properties of bimetallic PtRu/Ru(0001) model catalysts
    Chem. Phys. Chem., 11, 3123-3132 (2010)
    DOI: 10.1002/cphc.201000391

     

    A. Fraile Rodríguez, A. Kleibert, J. Bansmann, and F. Nolting
    Probing single magnetic nanoparticles by polarization dependent soft x-ray absorption spectromicroscopy
    J. Phys. D: Appl. Phys., 43, 474006 (2010)
    DOI: 10.1088/0022-3727/43/47/474006

2009

    P. Tripathy, A. Mishra, S. Ram, H.-J. Fecht, J. Bansmann, and R.J. Behm
    X-ray photoelectron spectrum in surface interfacing of gold nanoparticles with polymer molecules in a hybrid nanocomposite structure
    Nanotechnology, 20, 075701 (2009)
    DOI: 10.1088/0957-4484/20/7/075701

    A. Kleibert, K.H. Meiwes-Broer, and J. Bansmann
    Size-dependent magnetic spin and orbital moments of Fe nanoparticles deposited onto Co/W(110)
    Phys. Rev. B, 79, 125423 (2009)
    DOI: 10.1103/PhysRevB.79.125423

    Y. Ma, T. Diemant, J. Bansmann, and R.J. Behm
    Formation, stability and CO adsorption properties of PdAg/Pd(111) surface alloys 
    Surf. Sci., 603, 1046-1054 (2009).
    DOI: 10.1016/j.susc.2009.02.024

    H. Hartmann, T. Diemant, A. Bergbreiter, J. Bansmann, H.E. Hoster, and R. J. Behm
    Surface alloy formation, short-range order, and deuterium adsorption properties of monolayer PdRu/Ru(0001) surface alloys
    Surf. Sci., 603, 1439-1455 (2009).
    DOI: 10.1016/J.susc.2008.10.055

    H. Hartmann, T. Diemant, J. Bansmann, and R.J. Behm
    Chemical properties of structurally well-defined PdRu/Ru(0001) surface alloys – Interaction with CO
    Surf. Sci., 603, 1456-1466 (2009).
    DOI: 10.1016/j.susc.2008.10.052

    T. Diemant, J. Bansmann, and R.J. Behm
    CO oxidation on planar Au/TiO2 model catalysts: deactivation and the influence of water
    Vacuum, 84, 193-196 (2009).
    DOI: 10.1016/j.vacuum.2009.04.004

2008

    A. Kleibert, F. Bulut, R.K. Gebhardt, W. Rosellen, D. Sudfeld, J. Passig, J. Bansmann, K.H. Meiwes-Broer, and M. Getzlaff
    Correlation of shape and magnetic anisotropy of supported mass-filtered Fe and FeCo alloy nanoparticles on W(110)
    J. Physics: Condensed Matter 20, 445005 (2008)
    DOI:  10.1088/0953/20/44/445005

2007

    S. Ram, A. Gautam, H.J. Fecht, J. Cai, J. Bansmann, and R.J. Behm
    A new allotrope structure of silver nanocrystals in anisotropic nucleation and growth in support over planar polymer molecules
    Phil. Mag. Lett. 87, 361-372 (2007).
    DOI: 10.1080/09500830701191401

    A. Fraile Rodriguez, F. Nolting, J. Bansmann, A. Kleibert, and L. J. Heyderman
    X-ray imaging and spectroscopy of individual cobalt nanoparticles using photoemission electron microscopy
    J. Magn. Magn. Mat. 316, 426-428 (2007).
    DOI: 10.1016/j.jmmm.2007.03.093

    T. Diemant, Z. Zhao, H. Rauscher, J. Bansmann, and R.J. Behm
    Interaction of CO with planar Au/TiO2 model catalysts at elevated pressures
    Topics Catal. 44, 83-93 (2007).
    DOI: 10.1007/s11244-007-0281-0

    A. Kleibert, J. Passig, K.-H. Meiwes-Broer, M. Getzlaff, and J. Bansmann
    Structure and magnetic moments of mass-filtered deposited nanoparticles
    J. Appl. Physics 101, 114318 (2007).
    DOI: 10.1063/1.2745330

    T. Diemant, Z. Zhong, H. Rauscher, J. Bansmann, and R.J. Behm
    High-pressure study on the adsorption and oxidation of CO on gold/titania model catalysts
    Surf. Sci. 601, 3801-3804 (2007).
    DOI: 10.1016/j.susc.2007.04.018

    J. Bansmann, S. Kielbassa, H. Hoster, F. Weigl, H.G. Boyen, P. Ziemann, and R.J. Behm
    Controlling the interparticle spacing of Au-Salt loaded micelles and Au nanoparticles on flat surfaces
    Langmuir 23, 10150-10155 (2007).
    DOI: 10.1021/la7012304

    M. Roos, S. Kielbassa, C. Schirling, T. Häring, J. Bansmann, and R.J. Behm
    Scanning mass spectrometer for quantitative reaction studies on catalytically active microstructures
    Rev. Sci. Instrum. 78, 084104-084113 (2007).
    DOI: 10.1063/1.2777167

    T. Diemant, H. Hartmann, J. Bansmann, and R. J. Behm
    CO adsorption energy on planar Au/TiO2 model catalysts under catalytically relevant conditions
    J. Catal. 252, 171-177 (2007).
    DOI: 10.1016/j.jcat.2007.09.024

    J. Bansmann, A. Kleibert, F. Bulut, M. Getzlaff, P. Imperia, C. Boeglin, and K.-H. Meiwes-Broer
    Temperature dependent magnetic spin and orbital moments of mass-filtered cobalt clusters on Au(111)
    Europ. Phys. J. D 45, 521-528 (2007).
    DOI: 10.1140/epjd/e2007-00238-x

2006

    S. Kielbassa, A. Häbich, J. Schnaidt, J. Bansmann, F. Weigl, H.G. Boyen, P. Ziemann, and R.J. Behm
    On the morphology and stability of Au nanoparticles on TiO2(110) prepared from micelle-stabilized precursors
    Langmuir, 22, 7873-7880 (2006).
    DOI: 10.1021/la0610102

     

    Z. Zhao, T. Diemant, D. Rosenthal, K. Christmann, J. Bansmann, H. Rauscher, and R.J. Behm
    Au/TiO2/Ru(0001) model catalysts and their interaction with CO
    Surf. Sci., 600, 4992-5003 (2006).
    DOI:10.1016/j.susc.2006.08.022

     

    K.L. Jonas, V. v. Oeynhausen, J. Bansmann, and K.H. Meiwes-Broer
    Tunnelling spectroscopy on silver islands and large deposited silver clusters on Ge(001)
    Appl. Phys. A, 82, 131-137 (2006).
    DOI: 10.1007/s00339-005-3341-y

     

    M. Getzlaff, J. Bansmann, A. Kleibert, F. Bulut, R.K. Gebhardt, and K.H. Meiwes-Broer
    Structure, composition and magnetic properties of size-selected FeCo alloy clusters on surfaces
    Appl. Phys. A, 82, 95-101 (2006).
    DOI: 10.1007/s00339-005-3347-5

     

    J. Bansmann, M. Getzlaff, F. Bulut, R.K. Gebhardt, A. Kleibert, and K.H. Meiwes-Broer
    Mass-filtered cobalt clusters in contact with epitaxially ordered metal surfaces
    Appl. Phys. A, 82, 73-79 (2006).
    DOI: 10.1007/s00339-005-3342-x

2005