Transport properties of catalyst supports studied by pulsed field gradient (PFG) and 2D exchange (EXSY) NMR spectroscopy

Weiland, Erika; Springuel‐Huet, Marie‐Anne; Nossov, Andreï; Guenneau, Flavien; Quoinneaud, Anne-Agathe; Gédéon, A.

doi:10.1039/c5nj02952j

Cited by 7 publications

(7 citation statements)

References 38 publications

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“…[ 76 ] Recently, it has been shown how the combination of the results of 129 Xe EXSY and PFG NMR diffusometry can yield information about porosity of materials over several length scales. [ 77 ]…”

Section: Hierarchical Materialsmentioning

confidence: 99%

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

Wisser

Hartmann

2020

Adv Materials Inter

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A large number of functional and catalytic materials exhibit porosity, often on different length scales and with a hierarchical structure. The assessment of pore sizes, pore geometry, and pore interconnectivity is complex and usually not feasible by classical spectroscopic and diffraction techniques. One of the most powerful methods to probe these parameters is nuclear magnetic resonance (NMR) spectroscopy of xenon, which is introduced into the pore system. Adsorbed to the pore walls, it acts as probe nucleus. In this tutorial review, an introduction into the basic principles of 129Xe NMR spectroscopy and the models developed to determine pore sizes in different materials are given. The possibilities and limitations of this method for obtaining insights into hierarchical structures of functional materials are highlighted and a review of recent works is presented.

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Section: Hierarchical Materialsmentioning

confidence: 99%

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

Wisser

Hartmann

2020

Adv Materials Inter

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“…A detailed report by Gedeon, Springuel‐Huet and co‐workers on the 1 H and 129 Xe pulse field gradient as well as 129 Xe‐ 129 Xe EXSY NMR studies of the transport properties of n ‐hexane and xenon demonstrated self‐diffusivity of xenon and n ‐hexane in alumina supports. The obtained values were used to evaluate the tortuosity of the complex porosity of the alumina.…”

Section: Part Iv: Exchange Involving Different Phasesmentioning

confidence: 99%

Mechanisms and Beyond: Elucidation of Fluxional Dynamics by Exchange NMR Spectroscopy

Nikitin

O'Gara

2019

Chemistry A European J

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Detailed mechanistic information is crucial to our understanding of reaction pathways and selectivity. Dynamic exchange NMR techniques, in particular 2D exchange spectroscopy (EXSY) and its modifications, provide indispensable intricate information on the mechanisms of organic and inorganic reactions and other phenomena, for example, the dynamics of interfacial processes. In this Review, key results from exchange NMR studies of small molecules over the last few decades are systemised and discussed. After a brief introduction to the theory, the key types of dynamic processes are identified and fundamental examples given of intra‐ and intermolecular reactions, which, in turn, could involve, or not, bond‐making and bond‐breaking events. Following that logic, internal molecular rotation, intramolecular stereomutation and molecular recognition will first be considered because they do not typically involve bond breaking. Then, rearrangements, substitution‐type reactions, cyclisations, additions and other processes affecting chemical bonds will be discussed. Finally, interfacial molecular dynamics and unexpected combinations of different types of fluxional processes will also be highlighted. How exchange NMR spectroscopy helps to identify conformational changes, coordination and molecular recognition processes as well as quantify reaction energy barriers and extract detailed mechanistic information by using reaction rate theory in conjunction with computational techniques will be shown.

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“…In general, the EXSY experiment is a robust tool to probe exchange and pore interconnectivity. Numerous 129 Xe NMR studies of porous materials used the two-dimensional approach. , However, the performance of a full set of 2D experiments with different mixing times is extremely time consuming . Thus, a conventional selective 1D approach was chosen in this work to limit the experimental time.…”

Section: Resultsmentioning

confidence: 99%

Hyperpolarized ¹²⁹Xe NMR as an Alternative Approach for Investigating Structure and Transport in Ordered Mesoporous Materials Prepared via Pseudomorphic Transformation

Hollenbach¹,

Küster²,

Uhlig

et al. 2017

J. Phys. Chem. C

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The stepwise pseudomorphic transformation of silica gel and porous glass into MCM-41 (Mobil Composition of Matter No. 41) has been investigated for the first time with hyperpolarized 129Xe NMR. The changes in structure were followed by changes in the line shape and chemical shift of the 129Xe NMR signals, whereby variable temperature (VT)-NMR and selective 1D exchange spectroscopy (EXSY) experiments revealed differences in the mechanism of the transformation, depending on the starting material.

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Transport properties of catalyst supports studied by pulsed field gradient (PFG) and 2D exchange (EXSY) NMR spectroscopy

Cited by 7 publications

References 38 publications

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

Mechanisms and Beyond: Elucidation of Fluxional Dynamics by Exchange NMR Spectroscopy

Hyperpolarized ¹²⁹Xe NMR as an Alternative Approach for Investigating Structure and Transport in Ordered Mesoporous Materials Prepared via Pseudomorphic Transformation

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Transport properties of catalyst supports studied by pulsed field gradient (PFG) and 2D exchange (EXSY) NMR spectroscopy

Cited by 7 publications

References 38 publications

129Xe NMR on Porous Materials: Basic Principles and Recent Applications

129Xe NMR on Porous Materials: Basic Principles and Recent Applications

Mechanisms and Beyond: Elucidation of Fluxional Dynamics by Exchange NMR Spectroscopy

Hyperpolarized 129Xe NMR as an Alternative Approach for Investigating Structure and Transport in Ordered Mesoporous Materials Prepared via Pseudomorphic Transformation

Contact Info

Product

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About

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

¹²⁹Xe NMR on Porous Materials: Basic Principles and Recent Applications

Hyperpolarized ¹²⁹Xe NMR as an Alternative Approach for Investigating Structure and Transport in Ordered Mesoporous Materials Prepared via Pseudomorphic Transformation