Dynamic equilibria in supported ionic liquid phase (SILP) catalysis: in situ IR spectroscopy identifies [Ru(CO)xCly]n species in water gas shift catalysis

Bauer T, Stepic R, Wolf P, Kollhoff F, Karawacka W, Wick C, Haumann M, Wasserscheid P, Smith DM, Smith AS, Libuda J (2018)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2018

Journal

Catalysis: Science and Technology Royal Society of Chemistry

Book Volume: 8

Pages Range: 344-357

Journal Issue: 1

DOI: 10.1039/C7CY02199B

Open Access Link: http://pubs.rsc.org/en/content/articlelanding/2018/cy/c7cy02199b#!divAbstract

Abstract

Ru-based supported ionic liquid phase (SILP) systems efficiently catalyze the low-temperature water-gas

shift reaction (WGSR). While previous studies suggest that Ru-carbonyl species play an important role in

the mechanism, detailed knowledge on the catalytically active species is still missing. To identify these carbonyl

complexes, we apply in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in

combination with density functional theory (DFT). Investigations of an as-prepared [R(CO)3Cl2]2/

[C4C1C1Im]Cl/Al2O3 catalyst indicate splitting of the dimer induced by Cl−. Subsequently, an equilibrium between

several [R(CO)xCly]n species is established, in which the IL serves as an effectively infinite Cl− reservoir.

We find that the major species in the system freshly-prepared from [R(CO)3Cl2]2 is indeed

[R(CO)3Cl3]−. A smaller amount of [R(CO)2Cl3]− and chloride-rich species [R(CO)2Cl4]2− or [RuCOCl4]2−

are also found in the SILP. Similar Ru-carbonyl species are observed during carbonylation of RuCl3/

[C4C1C1Im]Cl/Al2O3, another potential WGSR catalyst. The response of [Ru(CO)3Cl2]2/[C4C1C1Im]Cl/Al2O3

to heating and/or CO dosing was probed in situ and the results confirm the presence of the equilibrium

proposed above.

Authors with CRIS profile

Tanja Retzer Professur für Physikalische Chemie Robert Stepic Physics Underlying Life Science Patrick Wolf Lehrstuhl für Chemische Reaktionstechnik Fabian Kollhoff Lehrstuhl für Physikalische Chemie II Christian Wick Physics Underlying Life Science Marco Haumann Lehrstuhl für Chemische Reaktionstechnik Peter Wasserscheid Lehrstuhl für Chemische Reaktionstechnik Ana-Suncana Smith Physics Underlying Life Science Jörg Libuda Professur für Physikalische Chemie

Additional Organisation(s)

Exzellenz-Cluster Engineering of Advanced Materials

Involved external institutions

Rudjer Boskovic Institute (RBI) / Institut Ruđer Bošković (IRB)

Croatia (HR)

How to cite

APA:

Bauer, T., Stepic, R., Wolf, P., Kollhoff, F., Karawacka, W., Wick, C.,... Libuda, J. (2018). Dynamic equilibria in supported ionic liquid phase (SILP) catalysis: in situ IR spectroscopy identifies [Ru(CO)xCly]n species in water gas shift catalysis. Catalysis: Science and Technology, 8(1), 344-357. https://doi.org/10.1039/C7CY02199B

MLA:

Bauer, Tanja, et al. "Dynamic equilibria in supported ionic liquid phase (SILP) catalysis: in situ IR spectroscopy identifies [Ru(CO)xCly]n species in water gas shift catalysis." Catalysis: Science and Technology 8.1 (2018): 344-357.

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