Physical Sciences and Mathematics Commons^™

Solid State Nmr Spectroscopic Characterization Of Metal Organic Frameworks, Vinicius Martins

Electronic Thesis and Dissertation Repository

Metal-organic frameworks are porous organic-inorganic materials that have attracted enormous attention due to their promising capabilities for several technologies, including carbon dioxide capture and storage, gas separation, and heterogeneous catalysis. The performance of MOFs for these applications is directly linked to their properties and, by extension, structures. Therefore, it is essential to understand the structure – property relationship. Solid-state NMR (SSNMR) spectroscopy is a technique that provides complementary information to X-ray diffraction-based techniques. SSNMR can provide short-range information around the NMR-active nucleus of interest. Furthermore, SSNMR can provide additional information regarding host-guest interactions and dynamics of adsorbed molecules, which play …

High-Pressure Studies Of Flexible Metal-Organic Frameworks And Their Performance For Co2 Adsorption Using Infrared Spectroscopy, Boqing Li

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are crystalline porous materials comprising metal ions/clusters and organic linkers. MOFs feature very large surface area and broad tunability, which distinguish them from traditional CO₂ adsorbents. High external pressure can significantly modify the framework structures and CO₂ adsorption properties of MOFs. MIL-53(Al) and NH₂-MIL-53(Al) exhibit excellent CO₂ affinity by forming hydrogen bonds between bridging OH groups and adsorbed CO₂. We used in situ infrared spectroscopy to investigate the high-pressure performance of their framework structures and CO₂ adsorption capacities. Diamond anvil cell was employed to apply high pressures in gigapascal …

Investigations Of The High Pressure Effects On Structural Properties And Co2 Adsorption Performance Of Mofs Using Vibrational Spectroscopy, Shan Jiang

Electronic Thesis and Dissertation Repository

The pre- and post-combustion carbon dioxide capture has drawn much attention in the past few decades owing to the increasing concentration of CO₂ in the atmosphere. Among all the potential solid adsorbents for CO₂ capture, metal-organic frameworks (MOFs) are a promising class of materials due to their large surface areas, high tunability and their high selectivity for gas adsorption applications. It has been widely demonstrated that the application of high external pressure in gigapascal level can substantially tune the structure, pore size and opening of porous material. Consequently, the structural, as well as gas adsorption properties of these …

Adsorbed Gas Behaviour And Guest-Host Interactions In Ultramicroporous Metal-Organic Frameworks, Bligh Desveaux

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a class of porous materials that have attracted much attention due to their large surface areas, high tunability and their high selectivity for gas adsorption applications. In this work, solid-state nuclear magnetic resonance (SSNMR) experiments and single crystal X-ray diffraction (SCXRD) experiments are used to investigate carbon dioxide adsorption within the ultramicroporous MOFs SIFSIX-3-Zn (Chapter 2) and ZnAtzOx. (Chapter 3). Analysis finds that the CO₂ SIFSIX-3-Zn undergoes wobbling motions with a low temperature dependence, and in ZnAtzOx undergoes wobbling and hopping motions with a low temperature dependence. SCXRD is used to precisely determine the CO …

Studying Metal-Organic Frameworks Via Solid-State Nmr: Gas Dynamics, Structure Determination, And Phase Transition, Yue Zhang

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a class of microporous materials constructed from virtually endless combinations of metal centres and organic linkers. MOFs have attracted intense research interest in recent decades, since MOFs have outstanding properties such as extremely high surface area, tuneable pore topology, good stability, and many others. MOFs are also promising candidates for gas storage. In this work, solid-state NMR (SSNMR) spectroscopy has been investigated to study MOFs and their guest molecules, since SSNMR can provide information on the short-range environment about target nuclei and can also reveal the dynamics of guest molecules.

An introduction to MOFs and SSNMR …

Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks And Zeolites Via Solid-State Nuclear Magnetic Resonance, Bowei Wu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are synthetic compounds with crystalline microporous structures, consisting of metal centres joined by organic linkers. Zeolites are a class of crystalline porous materials featuring negatively charged aluminosilicate frameworks and charge-balancing cations.

In this work, solid-state nuclear magnetic resonance (SSNMR) is used to probe guest molecule locations and dynamics in MOFs and zeolites, yielding detailed informations of guest motion within these porous materials

Chapter 2 describes SSNMR dynamic studies of ¹³CO₂, ¹³CO and C₂D₄ adsorption behaviour in the α - zinc formate MOF, [Zn₃(HCOO)₆], which were performed …

In Situ High-Pressure Study Of Metal-Organic Frameworks And Their Performance For Co2 Storage Probed By Vibrational Spectroscopy, Yue Hu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are an important class of porous materials, owing to their potential applications in a variety of areas, including gas storage, molecular separations, catalysis, sensors and so on. Most importantly, their extraordinary surface areas, tunable pore properties and potential for industrial scale production have made MOFs a promising material for clean energy applications, such as CO₂ storage. The chemical and mechanical stabilities of MOFs play a crucial role in their CO₂ storage performance, which require extreme loading pressures that are far beyond ambient pressure at times. Application of high external pressure (e.g., in gigapascal range) on …