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Unveiling catalytic species in suspension/solution-based reactions by in situ X-ray absorption spectroscopy

evolution of palladium and ruthenium species

Yuan, Ning (2019). Unveiling catalytic species in suspension/solution-based reactions by in situ X-ray absorption spectroscopy. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2019:33
ISBN 978-91-7760-384-9
eISBN 978-91-7760-385-6
[Doctoral thesis]

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The palladium (Pd) and ruthenium (Ru) species in several attractive catalysts have been probed using X-ray absorption spectroscopy (XAS). The study of catalyst evolution in suspension- and solution-based reactions was the primary aim. It was achieved by performing in situ XAS experiments on Pd and Ru over the course of the reactions. A custom-made reactor was employed which allowed the catalysts to be mixed with other reaction components under desired conditions.

The first system investigated was the Heck coupling reaction catalyzed by Pd(II) complexes embedded on metal-organic frameworks. Mononuclear Pd complexes are the active species at the first stage of the measurement which then gradually transform into Pd nanoclusters. At a later stage of the measurement, chloride ligands start to bind to surface atoms of the Pd nanoclusters, leading to a deactivation of the catalyst. Pd(II) carbene complexes catalyzing undirected C–H acetoxylation of benzene in the presence of an oxidant were then explored. A gradual ligand substitution occurs, and the mean oxidation state of Pd increases at the same time. At a later stage, Pd nanoclusters form, while the mean oxidation state of Pd returns to the start value. Deactivation of a heterogeneous Pd(II) catalyst during cycloisomerization of acetylenic acids was also investigated using in situ XAS. The choice of substrates showed to significantly influence the nature of Pd species, and the formation of Pd(0) aggregates causes the deactivation. Moreover, strategies of reactivating the catalyst and prevention of the deactivation were developed and examined. In the end, the activation process of a Ru catalyst was studied and the structure of the intermediate was determined by in situ XAS. It was demonstrated that an electron-donating substituent on the cyclopentadiene ligand exhibits a promoting effect on the activation, while an electron-withdrawing substituent inhibits the activation.

Authors/Creators:Yuan, Ning
Title:Unveiling catalytic species in suspension/solution-based reactions by in situ X-ray absorption spectroscopy
Subtitle:evolution of palladium and ruthenium species
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2019
Number of Pages:133
INing Yuan,† Vlad Pascanu,† Zhehao Huang, Alejandro Valiente, Niclas Heidenreich, Sebastian Leubner, Andrew K. Inge, Jakob Gaar, Norbert Stock, Ingmar Persson,* Belén Martín-Matute* and Xiaodong Zou* (2018). Probing the Evolution of Palladium Species in Pd@MOF Cata-lysts during the Heck Coupling Reaction: An Operando X-Ray Absorption Spectroscopy Study. Journal of the American Chemical Society, 140, pp. 8206−8217.
IINing Yuan,†* Maitham H. Majeed,† Éva G. Bajnóczi, Axel R. Persson, L. Rein Wallenberg, A. Ken Inge, Niclas Heidenreich, Norbert Stock, Xiaodong Zou, Ola Wendt* and Ingmar Persson* (2019). In Situ XAS Study of the Local Structure and Oxidation State Evolutions of Palladium in a Reduced Graphene Oxide Supported Pd(II) Carbene Complex during an Undirected C−H Acetoxylation Reaction. Catalysis Science & Technology, 9, pp. 2025−2031.
IIINing Yuan,† Arnar Guðmundsson,† Karl P.J. Gustafson, Michael Oschmann, Oscar Verho, Ingmar Persson, Xiaodong Zou, Éva G. Bajnóczi* and Jan-Erling Bäckvall.* In Situ XAS Investigation of the Deactivation and Reactivation Mechanisms of a Heterogeneous Palladium(II) Catalyst During the Cycloisomerization of Acetylenic Acids (manuscript)
IVAlexandre Bruneau, Karl P. J. Gustafson, Ning Yuan, Ingmar Persson, Xiaodong Zou and Jan-Erling Bäckvall* (2017). Synthesis of Bensofurans and Indoles from Terminal Alkynes and Iodoaromatics Catalyzed by List of publications Recylable Palladium Nanoparticles Immobilized on Siliceous Mesocellular Foam. Chemistry: A European Journal, 23, pp. 12886–12891.
VKarl P. J. Gustafson,† Tamás Görbe,† Gonzalo De Gonzalo-Calvo, Ning Yuan, Cynthia Schreiber, Andrey Shchukarev, Cheuk-Wai Tai, Ingmar Persson, Xiaodong Zou and Jan-Erling Bäckvall.* Chemoenzymatic Dynamic Kinetic Resolution of Primary Benzylic Amines using Pd(0)- CalB CLEA as a Biohybrid Catalyst (submitted)
VIKarl P. J. Gustafson,† Arnar Guðmundsson,† Éva G. Bajnóczi,† Ning Yuan, Xiaodong Zou, Ingmar Persson* and Jan-Erling Bäckvall.* In Situ Structural Determination of a Homogeneous Ruthenium-Catalyst and its Activated Intermediates using X-Ray Absorption Spectroscopy (submitted)
Place of Publication:Uppsala
Publisher:Swedish University of Agricultural Sciences, Department of Molecular Sciences,
ISBN for printed version:978-91-7760-384-9
ISBN for electronic version:978-91-7760-385-6
Additional Information:The thesis has also been published by Stockholm University and in the repository of DIVa
Publication Type:Doctoral thesis
Article category:Other scientific
Full Text Status:Public
Agris subject categories.:X Agricola extesions > X50 Chemistry
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 104 Chemical Sciences > Analytical Chemistry
(A) Swedish standard research categories 2011 > 1 Natural sciences > 104 Chemical Sciences > Inorganic Chemistry
Keywords:palladiu uthenium species, catalysts, suspension and solution, in situ X-ray absorption spectroscopy, activation, deactivation
Permanent URL:
ID Code:16080
Faculty:NJ - Fakulteten för naturresurser och jordbruksvetenskap
Department:(NL, NJ) > Department of Molecular Sciences
Deposited By: SLUpub Connector
Deposited On:24 Apr 2019 06:50
Metadata Last Modified:07 Nov 2019 12:02

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