Interaction of Ester-Functionalized Ionic Liquids with Atomically-Defined Cobalt Oxides Surfaces: Adsorption, Reaction and Thermal Stability

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Xu T, Wähler T, Vecchietti J, Bonivardi A, Bauer T, Schwegler J, Schulz P, Wasserscheid P, Libuda J
Zeitschrift: Chemphyschem
Verlag: WILEY-V C H VERLAG GMBH
Jahr der Veröffentlichung: 2017
Band: 18
Heftnummer: 23
Seitenbereich: 3443-3453
ISSN: 1439-4235


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.


FAU-Autoren / FAU-Herausgeber

Bauer, Tanja
Lehrstuhl für Physikalische Chemie II
Libuda, Jörg Prof. Dr.
Professur für Physikalische Chemie
Schulz, Peter Dr.
Lehrstuhl für Chemische Reaktionstechnik
Schwegler, Johannes
Lehrstuhl für Chemische Reaktionstechnik
Wähler, Tobias
Lehrstuhl für Physikalische Chemie II
Wasserscheid, Peter Prof. Dr.
Lehrstuhl für Chemische Reaktionstechnik
Xu, Tao
Lehrstuhl für Physikalische Chemie II


Autor(en) der externen Einrichtung(en)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) / National Scientific and Technical Research Council


Zitierweisen

APA:
Xu, T., Wähler, T., Vecchietti, J., Bonivardi, A., Bauer, T., Schwegler, J.,... Libuda, J. (2017). Interaction of Ester-Functionalized Ionic Liquids with Atomically-Defined Cobalt Oxides Surfaces: Adsorption, Reaction and Thermal Stability. Chemphyschem, 18(23), 3443-3453. https://dx.doi.org/10.1002/cphc.201700843

MLA:
Xu, Tao, et al. "Interaction of Ester-Functionalized Ionic Liquids with Atomically-Defined Cobalt Oxides Surfaces: Adsorption, Reaction and Thermal Stability." Chemphyschem 18.23 (2017): 3443-3453.

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Zuletzt aktualisiert 2018-10-09 um 14:08