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

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.

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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://dx.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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