% Encoding: UTF-8
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@article{faucris.264257687,
abstract = {The transition-metal dichalcogenide HfS(2)is a promising alternative semiconductor with adequate band gap and high carrier mobility. However, a controllable growth of continuous HfS(2)films with selectivity for specific surfaces at a low temperature on a large scale has not been demonstrated yet. Herein, HfS(2)films are grown at 100 degrees C by atomic layer deposition (ALD) based on the precursors tetrakis(dimethylamido)hafnium and H2S. In situ vibrational spectroscopy allows for the definition of the temperature range over which (Me2N)(4)Hf chemisorbs as one monolayer. In that range, sequential exposures of the solid surface with (Me2N)(4)Hf and H2S result in self-limiting reactions that yield alternating surface termination with dimethylamide and thiol. Repeating the cycle grows smooth, continuous, stoichiometric films of thicknesses adjustable from angstroms to >100 nm, as demonstrated by spectroscopic ellipsometry, XRR, AFM, UV-vis and Raman spectroscopy, XPS, and TEM. The well-defined surface chemistry enables one to deposit HfS(2)selectively using, for example, patterns generated in molecular self-assembled monolayers. This novel ALD reaction combines several attractive features necessary for integrating HfS(2)into devices.},
author = {Cao, Yuanyuan and Wähler, Tobias and Park, Hyoungwon and Will, Johannes and Prihoda, Annemarie and Moses Badlyan, Narine and Fromm, Lukas and Yokosawa, Tadahiro and Wang, Bingzhe and Guldi, Dirk Michael and Görling, Andreas and Maultzsch, Janina and Unruh, Tobias and Spiecker, Erdmann and Halik, Marcus and Libuda, Jörg and Bachmann, Julien},
doi = {10.1002/admi.202001493},
faupublication = {yes},
journal = {Advanced Materials Interfaces},
keywords = {2D materials;atomic layer deposition;dichalcogenides;hafnium disulfide;thin films},
peerreviewed = {Yes},
title = {{Area}-{Selective} {Growth} of {HfS}(2){Thin} {Films} via {Atomic} {Layer} {Deposition} at {Low} {Temperature}},
volume = {7},
year = {2020}
}
@article{faucris.244316778,
abstract = {The transition-metal dichalcogenide HfS(2)is a promising alternative semiconductor with adequate band gap and high carrier mobility. However, a controllable growth of continuous HfS(2)films with selectivity for specific surfaces at a low temperature on a large scale has not been demonstrated yet. Herein, HfS(2)films are grown at 100 degrees C by atomic layer deposition (ALD) based on the precursors tetrakis(dimethylamido)hafnium and H2S. In situ vibrational spectroscopy allows for the definition of the temperature range over which (Me2N)(4)Hf chemisorbs as one monolayer. In that range, sequential exposures of the solid surface with (Me2N)(4)Hf and H2S result in self-limiting reactions that yield alternating surface termination with dimethylamide and thiol. Repeating the cycle grows smooth, continuous, stoichiometric films of thicknesses adjustable from angstroms to >100 nm, as demonstrated by spectroscopic ellipsometry, XRR, AFM, UV-vis and Raman spectroscopy, XPS, and TEM. The well-defined surface chemistry enables one to deposit HfS(2)selectively using, for example, patterns generated in molecular self-assembled monolayers. This novel ALD reaction combines several attractive features necessary for integrating HfS(2)into devices.},
author = {Cao, Yuanyuan and Wähler, Tobias and Park, Hyoungwon and Will, Johannes and Prihoda, Annemarie and Moses Badlyan, Narine and Fromm, Lukas and Yokosawa, Tadahiro and Wang, Bingzhe and Guldi, Dirk Michael and Görling, Andreas and Maultzsch, Janina and Unruh, Tobias and Spiecker, Erdmann and Halik, Marcus and Libuda, Jörg and Bachmann, Julien},
doi = {10.1002/admi.202001493},
faupublication = {yes},
journal = {Advanced Materials Interfaces},
keywords = {2D materials; atomic layer deposition; dichalcogenides; hafnium disulfide; thin films},
note = {CRIS-Team Scopus Importer:2020-10-23},
peerreviewed = {Yes},
title = {{Area}-{Selective} {Growth} of {HfS}(2){Thin} {Films} via {Atomic} {Layer} {Deposition} at {Low} {Temperature}},
volume = {7},
year = {2020}
}
@article{faucris.210898317,
abstract = {We have studied particle size effects on atomically-defined model catalysts both in ultrahigh vacuum (UHV) and under electrochemical (EC) conditions in liquid electrolytes. The model catalysts were prepared in UHV by physical vapour deposition (PVD) of Pt onto an ordered Co3O4(111) film on Ir(100), yielding nanoparticles (NPs) with an average size from 10 to 500 atoms per particle (0.8 to 3 nm). The model systems were characterized in UHV using surface science methods including scanning tunnelling microscopy (STM), before transferring them out of the UHV and into the electrolyte without contact to ambient conditions. By X-ray photoelectron spectroscopy (XPS) we show that the model surfaces are stable in the EC environment under the applied conditions (0.1 to 1 M phosphate buffer, pH 10, 0.33 to 1.03 V-RHE). As a reference, we study Pt(111) under identical conditions. In UHV, we also investigated the adsorption of CO using infrared reflection absorption spectroscopy (IRRAS). Under EC conditions, we performed equivalent experiments using EC infrared reflection absorption spectroscopy (EC-IRRAS) in combination with cyclic voltammetry (CV). Characteristic differences were observed between the IR spectra under EC conditions and in UHV. Besides the red-shift induced by the interfacial electric field (Stark effect), the EC IR bands of CO on Pt(111) show a larger width (by a factor of 2) as a result of local variations in the CO environment and coupling to the electrolyte. The CO IR bands of the Pt NPs are even broader (by a factor of 5), which is attributed to local variations of the interfacial electric field at the NP surface. Further pronounced differences are observed between the spectra taken in UHV and in the electrolyte regarding the site occupation and its dependence on particle size. In UHV, adsorption at on-top sites is preferred on Pt(111) at low coverage and similar adsorption ratios of on-top and bridge-bonded CO are formed at saturation coverage. In sharp contrast, on-top adsorption of CO on Pt(111) is partially suppressed under EC conditions. This effect is attributed to the competitive adsorption of anions from the electrolyte and leads to a clear preference for bridge sites at higher potentials (>0.5 V-RHE). For the Pt NPs, the situation is different and an increasing fraction of on-top CO is observed with decreasing particle size, both under EC conditions and in UHV. For the smallest particles (10-20 atoms) we do not detect any bridge-bonded CO. This change in site preference as a function of particle size is attributed to stronger on-top adsorption on low-coordinated Pt atoms of small Pt NPs. The effect leads to a clear preference for on-top adsorption in the electrolyte even at low CO coverage and over the full potential range studied.},
author = {Faisal, Firas and Stumm, Corinna and Bertram, Manon and Wähler, Tobias and Schuster, Ralf and Xiang, Feifei and Lytken, Ole and Katsounaros, Ioannis and Mayrhofer, Karl and Schneider, M. Alexander and Brummel, Olaf and Libuda, Jörg},
doi = {10.1039/c8cp03770a},
faupublication = {yes},
journal = {Physical Chemistry Chemical Physics},
pages = {23702-23716},
peerreviewed = {Yes},
title = {{Atomically}-defined model catalysts in ultrahigh vacuum and in liquid electrolytes: particle size-dependent {CO} adsorption on {Pt} nanoparticles on ordered {Co3O4}(111) films},
volume = {20},
year = {2018}
}
@article{faucris.212021151,
abstract = {We have investigated the adsorption and dissociation of water and its co-adsorption with CO on atomically defined cobalt oxide nanoislands on Pt(111). The CoO islands were prepared under ultrahigh vacuum (UHV) conditions by reactive deposition of Co metal in oxygen atmosphere. The island structure was characterized by scanning tunneling microscopy (STM), showing that the nanoislands consist of a CoO bilayer and are regularly shaped with island edges that are mainly terminated by Co2+ ions. D2O was dosed in UHV onto the CoO islands on Pt(111) after pre-saturation with CO. D2O dissociation was monitored in situ by isothermal and temperature programmed infrared reflection absorption spectroscopy (IRAS). Isotopic exchange experiments were performed with H2O, D2O, and D-2 O-18 to elucidate the nature of the hydroxyl groups. Three principal types of OD species are identified: (i) isolated OD at the edges of the CoO islands (Co-OeD), (ii) OD groups within larger hydroxylated areas on the CoO islands (Co-OcD), and (iii) isolated OD groups on the CoO terraces (Co-OtD). At 400 K, water adsorbs dissociatively on the CoO islands and forms isolated hydroxyl species (Co-OeD) at the island edges only. At room temperature (300 K), the coverage of hydroxyl groups increases rapidly, in line with the water-assisted hydroxylation reaction suggested previously. Adsorption experiments with D-2 O-18 suggest that two equivalent groups are formed from one water molecule after dissociation at island edges, leading to the formation of larger hydroxylated areas on the CoO islands (Co-OcD) and, in addition, isolated OD species on the CoO terraces (Co-OtD). While the initial step of D2O dissociation is facile, the formation of larger hydroxylated areas is a slow and irreversible process. At 200 K, the formation of hydroxylated areas is accompanied by the co-adsorption of molecular water. The hydroxyl groups on the CoO islands are shown to interact with the CO preadsorbed on the CoO/Pt(111) model system. In particular, we observe a new CO species, stabilized by OD groups on the CoO islands, which adsorbs much stronger than CO on the OD-free CoO surface.},
author = {Wähler, Tobias and Hohner, Chantal and Sun, Zhaozong and Schuster, Ralf and Rodriguez-Fernandez, Jonathan and Lauristen, Jeppe Vang and Libuda, Jörg},
doi = {10.1557/jmr.2018.388},
faupublication = {yes},
journal = {Journal of Materials Research},
note = {CRIS-Team WoS Importer:2019-03-01},
pages = {379-393},
peerreviewed = {Yes},
title = {{Dissociation} of water on atomically-defined cobalt oxide nanoislands on {Pt}(111) and its effect on the adsorption of {CO}},
volume = {34},
year = {2019}
}
@article{faucris.203326155,
abstract = {Electrocatalysis is at the heart of our future transition to a renewable energy system. Most energy storage and conversion technologies for renewables rely on electrocatalytic processes and, with increasing availability of cheap electrical energy from renewables, chemical production will witness electrification in the near future(1-3). However, our fundamental understanding of electrocatalysis lags behind the field of classical heterogeneous catalysis that has been the dominating chemical technology for a long time. Here, we describe a new strategy to advance fundamental studies on electrocatalytic materials. We propose to 'electrify' complex oxide-based model catalysts made by surface science methods to explore electrocatalytic reactions in liquid electrolytes. We demonstrate the feasibility of this concept by transferring an atomically defined platinum/cobalt oxide model catalyst into the electrochemical environment while preserving its atomic surface structure. Using this approach, we explore particle size effects and identify hitherto unknown metal-support interactions that stabilize oxidized platinum at the nanoparticle interface. The metal-support interactions open a new synergistic reaction pathway that involves both metallic and oxidized platinum. Our results illustrate the potential of the concept, which makes available a systematic approach to build atomically defined model electrodes for fundamental electrocatalytic studies.},
author = {Faisal, Firas and Stumm, Corinna and Bertram, Manon and Waidhas, Fabian and Lykhach, Yaroslava and Cherevko, Serhiy and Xiang, Feifei and Ammon, Maximilian Michael and Vorokhta, Mykhailo and Smid, Bretislav and Skala, Tomas and Tsud, Nataliya and Neitzel, Armin and Beranova, Klara and Prince, Kevin C. and Geiger, Simon and Kasian, Olga and Wähler, Tobias and Schuster, Ralf and Schneider, M. Alexander and Matolin, Vladimir and Mayrhofer, Karl J. J. and Brummel, Olaf and Libuda, Jörg},
doi = {10.1038/s41563-018-0088-3},
faupublication = {yes},
journal = {Nature Materials},
pages = {592-+},
peerreviewed = {Yes},
title = {{Electrifying} model catalysts for understanding electrocatalytic reactions in liquid electrolytes},
volume = {17},
year = {2018}
}
@article{faucris.210906330,
abstract = {Electronic metal-support interactions play a key role in the design of heterogeneous catalysts, as they provide a tool for tuning catalytic properties and enhancing catalyst stability. In this work, we explore the role of metal- support interactions in electrocatalysis using a model approach. We investigate the adsorption and reaction behavior of atomically defined Pt/Co3O4 model catalysts under ultrahigh vacuum (UHV) and under electrochemical conditions. The model systems were prepared by physical vapor deposition (PVD) of Pt onto well-ordered Co3O4(111) films on Ir(100), varying the average Pt nanoparticle (NP) size between 10 and 500 atoms per NP. In UHV, the model catalysts were characterized by synchrotron radiation photoelectron spectroscopy (SRPES), temperature-programmed desorption (TPD), and infrared reflection-absorption spectroscopy (IRAS). By SRPES, we show that partially oxidized Pt delta+ species are formed at the interface with the Co3O4 support. CO adsorbs weakly on these Pt delta+ sites and can be identified by IRAS at 115 K. Upon heating, CO adsorbed on metallic Pt-0 reacts with oxygen released from Co3O4 and gives rise to CO2 between 450 and 500 K. As a result of oxygen depletion, the Pt delta+ at the NP interface is reduced to Pt-0. Subsequently, we investigated the adsorption and oxidation of CO under electrochemical conditions on the same Pt/Co3O4 model catalysts. After preparation and characterization in UHV, the model systems were transferred into the electrochemical environment without exposure to ambient conditions. CO adsorption and electrooxidation were performed under conditions where the model system is stable (pH 10, 0.33-1.03 V-RHE, phosphate buffer). By electrochemical infrared reflection-absorption spectroscopy (EC-IRRAS), we show that CO does not adsorb at the partially oxidized Pt delta+ sites in the electrolyte at 300 K. Nevertheless, the Pet(delta+) species at the NP/oxide interface is reduced to Pt-0 upon repeated experimental cycles. This effect increases with decreasing NP size, in line with the behavior observed under UHV conditions. Our findings suggest that electronic metal-support interactions in metal/oxide catalysts play a very similar role in reactions with gaseous reactants and at the electrified interface.},
author = {Faisal, Firas and Bertram, Manon and Stumm, Corinna and Wähler, Tobias and Schuster, Ralf and Lykhach, Yaroslava and Neitzel, Armin and Skala, Tomas and Tsud, Nataliya and Beranova, Klara and Prince, Kevin C. and Matolin, Vladimir and Brummel, Olaf and Libuda, Jörg},
doi = {10.1021/acs.jpcc.8b05594},
faupublication = {yes},
journal = {Journal of Physical Chemistry C},
pages = {20787-20799},
peerreviewed = {Yes},
title = {{Electrocatalysis} with {Atomically} {Defined} {Model} {Systems}: {Metal}-{Support} {Interactions} between {Pt} {Nanoparticles} and {Co3O4}(111) under {Ultrahigh} {Vacuum} and in {Liquid} {Electrolytes}},
volume = {122},
year = {2018}
}
@article{faucris.106327364,
abstract = {Ionic liquids (IL) hold a great potential as novel electrolytes for applications in electronic materials and energy technology. The functionality of ILs in these applications relies on their interface to semiconducting nanomaterials. Therefore, methods to control the chemistry and structure of this interface are the key to assemble new IL-based electronic and electrochemical materials. Here, we present a new method to prepare a chemically well-defined interface between an oxide and an IL film. An imidazolium-based IL, which is carrying an ester group, is deposited onto cobalt oxide surface by evaporation. The IL binds covalently to the surface by thermally activated cleavage of the ester group and formation of a bridging carboxylate. The anchoring reaction shows high structure sensitivity, which implies that the IL film can be adhered selectively to specific oxide surfaces.},
author = {Xu, Tao and Wähler, Tobias and Vecchietti, Julia and Bonivardi, Adrian and Bauer, Tanja and Schwegler, Johannes and Schulz, Peter and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/anie.201704107},
faupublication = {yes},
journal = {Angewandte Chemie International Edition},
keywords = {chemical anchoring;cobalt oxide;ester functionalization;ionic liquids;vapor deposition},
pages = {9072-9076},
peerreviewed = {Yes},
title = {{Gluing} {Ionic} {Liquids} to {Oxide} {Surfaces}: {Chemical} {Anchoring} of {Functionalized} {Ionic} {Liquids} by {Vapor} {Deposition} onto {Cobalt}({II}) {Oxide}},
volume = {56},
year = {2017}
}
@article{faucris.213320131,
abstract = {Ionic liquids (IL) hold a great potential as novel electrolytes for applications in electronic materials and energy technology. The functionality of ILs in these applications relies on their interface to semiconducting nanomaterials. Therefore, methods to control the chemistry and structure of this interface are the key to assemble new IL-based electronic and electrochemical materials. Here, we present a new method to prepare a chemically well-defined interface between an oxide and an IL film. An imidazolium-based IL, which is carrying an ester group, is deposited onto cobalt oxide surface by evaporation. The IL binds covalently to the surface by thermally activated cleavage of the ester group and formation of a bridging carboxylate. The anchoring reaction shows high structure sensitivity, which implies that the IL film can be ``glued'' selectively specific oxide surfaces.},
author = {Xu, Tao and Wähler, Tobias and Vecchietti, Ph. D. Maria Julia and Bauer, Tanja and Schwegler, Johannes and Schulz, Peter and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/ange.201704107},
faupublication = {yes},
journal = {Angewandte Chemie},
note = {EAM Import::2019-03-13},
pages = {9200-9204},
peerreviewed = {Yes},
title = {{Gluing} ionic liquids to oxide surfaces: {Chemical} anchoring of functionalized ionic liquids by vapor deposition onto cobalt({II}) oxide // {Gluing} {Ionic} {Liquids} to {Oxide} {Surfaces}: {Chemical} {Anchoring} of {Functionalized} {Ionic} {Liquids} by {Vapor} {Deposition} onto {Cobalt}({II}) {Oxide}},
volume = {129},
year = {2017}
}
@article{faucris.203798678,
abstract = {Hybrid materials consisting of ionic liquid (ILs) films on supported oxides hold a great potential for applications in electronic and energy materials. In this work, we have performed surface science model studies scrutinizing the interaction of ester-functionalized ILs with atomically defined Co3O4(111) and CoO(100) surfaces. Both supports are prepared under ultra-high vacuum (UHV) conditions in form of thin films on Ir(100) single crystals. Subsequently, thin films of three ILs, 3-butyl-1-methyl imidazolium bis(trifluoromethyl-sulfonyl) imide ([BMIM][NTf2]), 3-(4-methoxyl-4-oxobutyl)-1-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ([MBMIM][NTf2]), and 3-(4-isopropoxy-4-oxobutyl)-1-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ([IPBMIM][NTf2]), were deposited on these surfaces by physical vapor deposition (PVD). Time-resolved and temperature-programmed infrared reflection absorption spectroscopy (TR-IRAS, TP-IRAS) were applied to monitor insitu the adsorption, film growth, and thermally induced desorption. By TP-IRAS, we determined the multilayer desorption temperature of [BMIM][NTf2] (360 +/- 5K), [MBMIM][NTf2] (380K) and [IPBMIM][NTf2] (380K). Upon deposition below the multilayer desorption temperature, all three ILs physisorb on both cobalt oxide surfaces. However, strong orientation effects are observed in the first monolayer, where the [NTf2](-) ion interacts with the surface through the SO2 groups and the CF3 groups point towards the vacuum. For the two functionalized ILs, the [MBMIM](+) and [IPBMIM](+) interact with the surface Co2+ ions of both surfaces via the CO group of their ester function. A very different behavior is found, if the ILs are deposited above the multilayer desorption temperature (400K). While for [BMIM][NTf2] and [MBMIM][NTf2] a molecularly adsorbed monolayer film is formed, [IPBMIM][NTf2] undergoes a chemical transformation on the CoO(100) surface. Here, the ester group is cleaved and the cation is chemically linked to the surface by formation of a surface carboxylate. The IL-derived species in the monolayer desorb at temperatures around 500 to 550K.},
author = {Xu, Tao and Wähler, Tobias and Vecchietti, Julia and Bonivardi, Adrian and Bauer, Tanja and Schwegler, Johannes and Schulz, Peter and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/cphc.201700843},
faupublication = {yes},
journal = {ChemPhysChem},
keywords = {chemical anchoring;cobalt oxide;ionic liquids;IRAS;thermal stability},
pages = {3443-3453},
peerreviewed = {Yes},
title = {{Interaction} of {Ester}-{Functionalized} {Ionic} {Liquids} with {Atomically}-{Defined} {Cobalt} {Oxides} {Surfaces}: {Adsorption}, {Reaction} and {Thermal} {Stability}},
volume = {18},
year = {2017}
}
@article{faucris.243043856,
abstract = {Low-temperature synthesis in ionic liquids (ILs) offers an efficient route for the preparation of metal oxide nanomaterials with tailor-made properties in a water-free environment. In this work, we investigated the role of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [C4C1Pyr][NTf2] in the synthesis of cobalt oxide nanoparticles from the molecular precursor Co2(CO)8 with ozone. We performed a model study in ultra-clean, ultrahigh vacuum (UHV) conditions by infrared reflection absorption spectroscopy (IRAS) using Au(111) as a substrate. Exposure of the pure precursor to ozone at low temperatures results in the oxidation of the first layers, leading to the formation of a disordered CoxOy passivation layer. Similar protection to ozone is also achieved by deposition of an IL layer onto a precursor film prior to ozone exposure. With increasing temperature, the IL gets permeable for ozone and a cobalt oxide film forms at the IL/precursor interface. We show that the interaction with the IL mediates the oxidation and leads to a more densely packed CoxOy film compared to a direct oxidation of the precursor.},
author = {Schuster, Ralf and Wähler, Tobias and Kettner, Miroslav and Agel, Friederike and Bauer, Tanja and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/open.202000187},
faupublication = {yes},
journal = {ChemistryOpen},
keywords = {cobalt oxide; ionic liquids; IR spectroscopy; low temperature synthesis; ozone},
note = {CRIS-Team Scopus Importer:2020-09-25},
peerreviewed = {Yes},
title = {{Model} {Studies} on the {Ozone}-{Mediated} {Synthesis} of {Cobalt} {Oxide} {Nanoparticles} from {Dicobalt} {Octacarbonyl} in {Ionic} {Liquids}},
year = {2020}
}
@article{faucris.242404030,
abstract = {Metalation of anchored porphyrins is essential for their functionality at hybrid interfaces. In this work, we have studied the anchoring and metalation of a functionalized porphyrin derivative, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP), on an atomically-defined CoO(100) film under ultrahigh vacuum (UHV) conditions. We follow both the anchoring to the oxide surface and the self-metalation by surface Co2+ ions via infrared reflection absorption spectroscopy (IRAS). At 150 K, MCTPP multilayer films adsorb molecularly on CoO(100) without anchoring to the surface. Upon heating to 195 K, the first layer of porphyrin molecules anchors via formation of a bridging surface carboxylate. Above 460 K, the MCTPP multilayer desorbs and only the anchored monolayer resides on the surface up to temperatures of 600 K approximately. The orientation of anchored MCTPP depends on the surface coverage. At low coverage, the MCTPP adopts a nearly flat-lying geometry, whereas an upright standing film is formed near the multilayer coverage. Self-metalation of MCTPP depends critically on the surface temperature, the coverage and on the molecular orientation. At 150 K, metalation is largely suppressed, while the degree of metalation increases with increasing temperature and reaches a value of around 60 % in the first monolayer at 450 K. At lower coverage higher metalation fractions (85 % and above) are observed, similar as for increasing temperature.},
author = {Wähler, Tobias and Schuster, Ralf and Libuda, Jörg},
doi = {10.1002/chem.202001331},
faupublication = {yes},
journal = {Chemistry - A European Journal},
keywords = {infrared Spectroscopy; interfaces; metalation; oxide surfaces; porphyrins},
note = {CRIS-Team Scopus Importer:2020-09-11},
peerreviewed = {Yes},
title = {{Self}-{Metalation} of {Anchored} {Porphyrins} on {Atomically} {Defined} {Cobalt} {Oxide} {Surfaces}: {In} situ {Studies} by {Surface} {Vibrational} {Spectroscopy}},
year = {2020}
}
@inproceedings{faucris.237946930,
address = {WASHINGTON},
author = {Yan, George and Wähler, Tobias and Schuster, Ralf and Schwarz, Matthias and Hohner, Chantal and Werner, Kristin and Libuda, Jörg and Sautet, Philippe},
booktitle = {ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY},
date = {2019-08-25/2019-08-29},
faupublication = {yes},
note = {CRIS-Team WoS Importer:2020-05-02},
peerreviewed = {unknown},
publisher = {AMER CHEMICAL SOC},
title = {{Triaqua} surface coordination complex on {Co3O4}(111)},
venue = {San Diego, CA},
year = {2019}
}
@article{faucris.216900025,
abstract = {The interaction of water with metal oxides controls their activity and stability in heterogeneous catalysis and electrocatalysis. In this work, we combine density functional theory calculations and infrared reflection absorption spectroscopy (IRAS) to identify the structural motifs formed upon interaction of water with an atomically defined Co3O4(111) surface. Three principal structures are observed: (i) strongly bound isolated OD, (ii) extended hydrogen-bonded OD/D2O structures, and (iii) a third structure which has not been reported to our knowledge. In this structure, surface Co2+ ions bind to three D2O molecules to form an octahedrally coordinated Co2+ with a "half hydration shell". We propose that this hydration structure represents an important intermediate in reorganization and dissolution on oxide surfaces which expose highly unsaturated surface cations.},
author = {Yan, George and Wähler, Tobias and Schuster, Ralf and Schwarz, Matthias and Hohner, Chantal and Werner, Kristin and Libuda, Jörg and Sautet, Philippe},
doi = {10.1021/jacs.9b00898},
faupublication = {yes},
journal = {Journal of the American Chemical Society},
note = {CRIS-Team WoS Importer:2019-05-03},
pages = {5623-5627},
peerreviewed = {Yes},
title = {{Water} on {Oxide} {Surfaces}: {A} {Triaqua} {Surface} {Coordination} {Complex} on {Co3O4}(111)},
volume = {141},
year = {2019}
}
@article{faucris.216808434,
abstract = {The interaction of water with metal oxides controls their activity and stability in heterogeneous catalysis and electrocatalysis. In this work, we combine density functional theory calculations and infrared reflection absorption spectroscopy (IRAS) to identify the structural motifs formed upon interaction of water with an atomically defined Co
3
O
4
(111) surface. Three principal structures are observed: (i) strongly bound isolated OD, (ii) extended hydrogen-bonded OD/D
2
O structures, and (iii) a third structure which has not been reported to our knowledge. In this structure, surface Co
2+
ions bind to three D
2
O molecules to form an octahedrally coordinated Co
2+
with a "half hydration shell". We propose that this hydration structure represents an important intermediate in reorganization and dissolution on oxide surfaces which expose highly unsaturated surface cations.},
author = {Yan, George and Wähler, Tobias and Schuster, Ralf and Schwarz, Matthias and Hohner, Chantal and Werner, Kristin and Libuda, Jörg and Sautet, Philippe},
doi = {10.1021/jacs.9b00898},
faupublication = {yes},
journal = {Journal of the American Chemical Society},
note = {CRIS-Team Scopus Importer:2019-05-02},
pages = {5623-5627},
peerreviewed = {Yes},
title = {{Water} on {Oxide} {Surfaces}: {A} {Triaqua} {Surface} {Coordination} {Complex} on {Co3O4}(111)},
volume = {141},
year = {2019}
}
@article{faucris.213813919,
abstract = {As reported previously, novel ZnO nanostructures can be grown by oxidation of [MeZnOtBu](4) building blocks with O-3 in ionic liquids (ILs). In this study, we have explored the role of the IL during ZnO formation by in-situ infrared reflection absorption spectroscopy (IRAS) in ultrahigh vacuum (UHV). [MeZnOtBu](4) and [C(2)C(1)Im][OTf] were (co-)deposited as thin films by physical vapor deposition (PVD) onto Au(111), separately or simultaneously. The IR spectrum of [MeZnOtBu](4) was analyzed between 300 and 4000 cm(-1) based on calculated spectra from density-functional theory (DFT). Spectral changes in the IL-related bands during the thermal treatment of [MeZnOtBu](4) in [C(2)C(1)Im][OTf] indicate the loss of the precursor ligands and the interaction of the IL with the growing ZnO aggregates. The films were treated with ozone (10(-6) mbar) in UHV and the spectral changes were monitored in-situ by IRAS. Slow ozonolysis of [C(2)C(1)Im][OTf] is observed. Spectroscopically we identify the primary ozonide formed by addition of O-3 to [C(2)C(1)Im](+) and suggest a reaction mechanism, which leads to a biuret derivative. Upon ozone treatment of mixed [MeZnOtBu](4)/[C(2)C(1)Im][OTf] films, ZnO aggregates are formed at the IL/vacuum interface. Ozonolysis of [C(2)C(1)Im][OTf] is suppressed. Upon annealing to 320 K, further ZnO aggregates are formed, leading to enclosure of [C(2)C(1)Im][OTf] in the ZnO film. At 380 K the IL is released from the mixed film. The pure [C(2)C(1)Im][OTf] desorbs at 420 K, leaving behind the ZnO phase.},
author = {Bauer, Tanja and Voggenreiter, Markus and Xu, Tao and Wähler, Tobias and Agel, Friederike and Pohako-Esko, Kaija and Schulz, Peter and Döpper, Tibor and Görling, Andreas and Polarz, Sebastian and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/zaac.201600345},
faupublication = {yes},
journal = {Zeitschrift für Anorganische und Allgemeine Chemie},
keywords = {Ionic liquid;Ozone;IR spectroscopy;ZnO nanoparticles;Surface science},
month = {Jan},
pages = {31-40},
peerreviewed = {Yes},
title = {{ZnO} {Nanoparticle} {Formation} from the {Molecular} {Precursor} [{MeZnOtBu}](4) by {Ozone} {Treatment} in {Ionic} {Liquids}: in-situ {Vibrational} {Spectroscopy} in an {Ultrahigh} {Vacuum} {Environment}},
volume = {643},
year = {2017}
}
@article{faucris.122487244,
abstract = {As reported previously, novel ZnO nanostructures can be grown by oxidation of [MeZnOtBu]“building blocks” with Oin ionic liquids (ILs). In this study, we have explored the role of the IL during ZnO formation by in-situ infrared reflection absorption spectroscopy (IRAS) in ultrahigh vacuum (UHV). [MeZnOtBu]and [CCIm][OTf] were (co-)deposited as thin films by physical vapor deposition (PVD) onto Au(111), separately or simultaneously. The IR spectrum of [MeZnOtBu]was analyzed between 300 and 4000 cmbased on calculated spectra from density-functional theory (DFT). Spectral changes in the IL-related bands during the thermal treatment of [MeZnOtBu]in [CCIm][OTf] indicate the loss of the precursor ligands and the interaction of the IL with the growing ZnO aggregates. The films were treated with ozone (10mbar) in UHV and the spectral changes were monitored in-situ by IRAS. Slow ozonolysis of [CCIm][OTf] is observed. Spectroscopically we identify the primary ozonide formed by addition of Oto [CCIm]and suggest a reaction mechanism, which leads to a biuret derivative. Upon ozone treatment of mixed [MeZnOtBu]/[CCIm][OTf] films, ZnO aggregates are formed at the IL/vacuum interface. Ozonolysis of [CCIm][OTf] is suppressed. Upon annealing to 320 K, further ZnO aggregates are formed, leading to enclosure of [CCIm][OTf] in the ZnO film. At 380 K the IL is released from the mixed film. The pure [CCIm][OTf] desorbs at 420 K, leaving behind the ZnO phase.},
author = {Bauer, Tanja and Voggenreiter, Markus and Xu, Tao and Wähler, Tobias and Agel, Friederike and Pohako-Esko, Kaija and Schulz, Peter and Döpper, Tibor and Görling, Andreas and Polarz, Sebastian and Wasserscheid, Peter and Libuda, Jörg},
doi = {10.1002/zaac.201600345},
faupublication = {yes},
journal = {Zeitschrift für Anorganische und Allgemeine Chemie},
keywords = {Ionic liquid; Ozone; IR spectroscopy; ZnO nanoparticles; Surface science},
pages = {31-40},
peerreviewed = {Yes},
title = {{ZnO} {Nanoparticle} {Formation} from the {Molecular} {Precursor} [{MeZnOtBu}]4 by {Ozone} {Treatment} in {Ionic} {Liquids}: in-situ {Vibrational} {Spectroscopy} in an {Ultrahigh} {Vacuum} {Environment}},
volume = {643},
year = {2017}
}