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Cordero Lanzac, Tomas; Ramirez, Adrian; Cruz-Fernandez, Marta; Zander, Hans-Jörg; Joensen, Finn & Meiswinkel, Andreas
[Vis alle 8 forfattere av denne artikkelen]
(2023).
Kinetic model, process design and LCA of a CO2 valorization plant to produce light hydrocarbon using a PdZn/ZrO2 + SAPO-34 catalyst.
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Rama, Raquel J.; Nova, Ainara & Olsbye, Unni
(2023).
Synthesis of linker-based bifunctional ligands for UiO-67 metal-organic frameworks.
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Sannes, Dag Kristian; Øien-Ødegaard, Sigurd; Aunan, Erlend; Nova Flores, Ainara & Olsbye, Unni
(2023).
Quantification of linker defects in UiO-type metal-organic frameworks.
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Cordero-Lanzac, Tomas; Ramirez, Adrian; Cruz-Fernandez, Marta; Zander, Hans-Jörg; Joensen, Finn & Meiswinkel, Andreas
[Vis alle 8 forfattere av denne artikkelen]
(2023).
Kinetic model, process design and LCA of a CO2 valorization plant to produce light hydrocarbon using a PdZn/ZrO2 + SAPO-34 catalyst.
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Olsbye, Unni
(2023).
Thermo-catalytic conversion of CO2 and H2 to higher hydrocarbons.
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Cao, Ning; Nova, Ainara; Olsbye, Unni & Balcells, David
(2022).
Structural characterization of Cu-UiO MOFs by DFT methods.
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Sannes, Dag Kristian; Øien-Ødegaard, Sigurd; Aunan, Erlend; Nova, Ainara & Olsbye, Unni
(2022).
Reliable determination of linker defects in UiO-type metal-organic frameworks.
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Sannes, Dag Kristian; Øien-Ødegaard, Sigurd; Aunan, Erlend; Nova, Ainara & Olsbye, Unni
(2022).
Reliable determination of linker defects in UiO-type metal-organic frameworks.
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Olsbye, Unni
(2022).
Oxygenate-mediated conversion of CO2 to light olefins and fuels - fundamental and applied aspects.
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Olsbye, Unni
(2022).
Selective partial oxidation of methane – status and outlook .
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Olsbye, Unni
(2022).
Kinetic and mechanistic studies of thermocatalytic reactions in dense and nanoporous catalysts.
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Olsbye, Unni
(2022).
Omdanning av CO2 til drivstoff, plastråstoff og kjemikalier Prosesser og livsløpsanalyser.
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Olsbye, Unni
(2022).
Site - structure - performance correlations in zeolite- and MOF-based catalysts.
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Olsbye, Unni
(2022).
Elucidation of mechanistic details of catalytic reactions in nanoporous materials by a combined experimental - computational approach.
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Olsbye, Unni
(2022).
Studies of diffusion and acid-catalyzed reactions in zeolites and zeotypes.
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Redekop, Evgeniy; Shostak, Vladyslav; Langberg, Geir Severin; Grønås, Terje; Constales, Denis & Galvita, Vladimir V.
[Vis alle 9 forfattere av denne artikkelen]
(2021).
Recent software developments for high throughput Temporal Analysis of Products (TAP) experiments and simulations.
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Cordero Lanzac, Tomas; Ramirez, Adrian & Olsbye, Unni
(2021).
The tandem approach to conversion of CO2 and H2 to light hydrocarbons
.
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Olsbye, Unni; Gutterød, Emil Sebastian; Lazzarini, Andrea; Fjermestad, Torstein; Pulumati, S.H. & Nova, Ainara
[Vis alle 7 forfattere av denne artikkelen]
(2021).
Mechanistic studies of CO2 hydrogenation to methanol, methane and CO over Pt-containing Zr-MOFs
.
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Olsbye, Unni
(2021).
Site - structure - performance correlations in zeolite- and MOF-based catalysts.
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Olsbye, Unni
(2020).
CCU - Considering a greenhouse gas as industrial carbon source.
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Arstad, Bjørnar; Dyballa, Michael Martin; Thorshaug, Knut; Pappas, Dimitrios K; Borfecchia, Elisa & Kvande, Karoline
[Vis alle 12 forfattere av denne artikkelen]
(2020).
Solid State NMR studies of the stepwise transformation of methane to methanol over Cu-Zeolites.
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Alireza, Hassani; Hansen, Eddy Walther; Olsbye, Unni & Fredriksen, Siw Bodil
(2020).
Segmental Orientation and Mobility of Ultra-high Molecular Weight Polyethylene
.
Vis sammendrag
Abstract:
Formation of entanglements in Ultra-High Molecular Weight Polyethylene (UHMWPE with average molecular weight exceeding 10^6 g.mol-1 limits their processability [1]. Entanglement characterization techniques mostly requires processing of nascent reactor powder, by melting. This will, however disturb the initial properties, and accordingly, the initial entanglement density in polymers. Therefore, Nuclear Magnetic Resonance (NMR) is an interesting alternative technique where the properties of UHMWPE can be explored in the solid state. However, during relevant NMR studies, the samples were either melted or exposed to time-intensive 13C high field NMR experiments [2]. Recently, simple low field, time-domain NMR with no need for isotope labeling, is gaining attention [3].
The aim of this study is to detect local mobility and orientation of chains across UHMWPE semi-crystalline network, in the solid state. The transverse relaxation time (T2) is determined from the Free Induction Decay (FID) of samples synthesized during controlled catalytic Polymerisation. The method is used to detect differences in dynamic behaviour of UHMWPE samples by mapping the crystalline/amorphous topology [3]. However, due to inhomogeneity in the magnetic field, obtaining detailed information about local chain diffusion is difficult with said experiment. Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence is designed to overcome this issue by refocusing the dephased magnetization in the transverse plane [4]. Thus, CPMG will be used for accurate measurement of the T2 distribution in UHMWPE samples at temperatures between 40-120 °C (below melting temperature).
References:
[1] A. Pawlak, "The Entanglements of Macromolecules and Their Influence on the Properties of Polymers," Macromolecular Chemistry and Physics, vol. 220, no. 10, p. 1900043, 2019.
[2] Y. Yao, S. Jiang, and S. Rastogi, "13C Solid State NMR Characterization of Structure and Orientation Development in the Narrow and Broad Molar Mass Disentangled UHMWPE," Macromolecules, vol. 47, no. 4, pp. 1371-1382, 2014.
[3] R. Bärenwald et al., "Local flips and chain motion in polyethylene crystallites: a comparison of melt-crystallized samples, reactor powders, and nanocrystals," Macromolecules, vol. 47, no. 15, pp. 5163-5173, 2014.
[4] A. K. Whittaker, T. Bremner, and F. O. Zelaya, "The effect of field inhomogeneities and molecular diffusion on the NMR transverse relaxation behaviour of polymer melts," Polymer, vol. 36, no. 11, pp. 2159-2164, 1995.
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Flatval, Jonas; Berg, Henriette Engen; Lillerud, Karl Petter; Olsbye, Unni; Nielsen, Claus Jørgen & Wilson, Steven Ray Haakon
[Vis alle 7 forfattere av denne artikkelen]
(2020).
Retention of nitramines on UiO-66 ZrMOF materials and silica-based reversed phase materials
.
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Andersen, Kari Anne; Flatval, Jonas; Mrša, Ago; Berg, Henriette Engen; Chavan, Sachin Maruti & Olsbye, Unni
[Vis alle 8 forfattere av denne artikkelen]
(2020).
Metal organic framework material UiO-66 as a stationary phase in liquid chromatography.
Vis sammendrag
Metal organic framework materials (MOFs) are interesting candidates for applications in multiple disciplines, where chromatography is one of the fields where possible applications might exist. The porous structure and large surface area are key features that make MOFs potential candidates for future stationary phases. In the present study, the MOF UiO-66 has been investigated as a stationary phase in a nano-liquid chromatography (LC) system.
UiO-66 is composed of zirconium oxide ion nodes and benzene dicarboxylate (BDC) linkers which form a face-centred cubic structure with octahedral pores (opening 6 Å, cavity 11 Å) and tetrahedral pores (opening 6 Å, cavity 7.5 Å) in a 1+2 ratio.
Figure adapted from Cliffe et al., Nature communications volume 5 (2014)1.
Columns with a 100 µm inner diameter have been packed in-house and tested in a simple LC-UV system for several test substances. The UiO-66 particles pack rapidly and yield columns with low back pressure. We observe reversed phase selectivity, but our experimental data also suggest other interaction mechanisms, phosphate group adsorption to zirconium oxide nodes among them.
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Redekop, Evgeniy; Johansson, Niclas; Kokkonen, Esko; Kalyva, Maria Evangelou; Urpelainen, Samuli & Diplas, Spyridon
[Vis alle 7 forfattere av denne artikkelen]
(2019).
Pt-Cu nanoparticles on 2D and 3D supports: an AP-XPS/TAP study.
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Gerz, Isabelle; Olsbye, Unni; Tilset, Mats & Amedjkouh, Mohamed
(2019).
Biomimetic Copper Complexes for Incorporation into MOFs.
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Ahoba-Sam, Christian & Olsbye, Unni
(2019).
On conversion of CO2 to value added products over a composite PdZn-ZSM-5 catalyst: a compromise or a penalty?
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Olsbye, Unni
(2019).
Catalytic conversion of gas phase molecules over UiO-67 Zr-MOFs - Two case studies.
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Redekop, Evgeniy; Johansson, Niclas; Kokkonen, Esko; Urpelainen, Samuli; Kalyva, Maria Evangelou & Affolter, Christopher
[Vis alle 8 forfattere av denne artikkelen]
(2019).
X-Ray spectroscopies and time-resolved kinetics for
advanced characterization of heterogeneous catalysts
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Redekop, Evgeniy; Johansson, Niclas; Urpelainen, Samuli; Kalyva, Maria Evangelou; Affolter, Christopher & Kokkonen, Esko
[Vis alle 10 forfattere av denne artikkelen]
(2019).
Combining transient kinetics with surface characterization to better
understand complex catalytic materials.
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Kalyva, Maria Evangelou; Redekop, Evgeniy; Johansson, Niclas; Urpelainen, Samuli; Gunnæs, Anette Eleonora & Diplas, Spyridon
[Vis alle 7 forfattere av denne artikkelen]
(2019).
AP-XPS study of bimetallic PtCu nanoparticles supported on SiO2 films.
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Johansson, Niclas; Redekop, Evgeniy; Olsbye, Unni & Urpelainen, Samuli
(2019).
TAPXPS: A novel approach to APXPS methodology.
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Sunding, Martin Fleissner; Jensen, Ingvild Julie Thue; Svenum, Ingeborg-Helene; Ivashenko, Oleksii; Redekop, Evgeniy & Wells, Justin
[Vis alle 11 forfattere av denne artikkelen]
(2019).
National Surface and Interface Analysis Laboratory (NICE II): From (near) in-situ to operando XPS analysis.
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Redekop, Evgeniy; Johansson, Niclas; Kalyva, Maria Evangelou; Urpelainen, Samuli; Diplas, Spyridon & Olsbye, Unni
(2019).
Is Temporal Analysis of Products (TAP) an operando technique? –
– Challenges and opportunities of coupling TAP with surface spectroscopies
.
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Gutterød, Emil Sebastian & Olsbye, Unni
(2019).
CO2 Hydrogenation over Pt-Functionalized UiO-67 Zr-MOFs.
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Kømurcu, Mustafa; Lazzarini, Andrea; Kaur, Gurpreet; Borfecchia, Elisa; Øien-Ødegaard, Sigurd & Gianolio, Diego
[Vis alle 9 forfattere av denne artikkelen]
(2019).
Co-catalyst free ethene dimerization over Zr-based metal-organic framework (UiO-67) functionalized with Ni and bipyridine.
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Olsbye, Unni
(2019).
Natural Gas Conversion in Microporous Catalysts, Zeotypes and Metal Organic Frameworks.
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Olsbye, Unni
(2019).
Zeolite catalysis - what can we learn from Temporal Analysis of Products (TAP) experiments?
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Kømurcu, Mustafa; Olsbye, Unni & Lillerud, Karl Petter
(2021).
Tailoring solid catalysts for the ethene oligomerization reaction.
Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet.
ISSN 1501-7710.
2021(2392).
Vis sammendrag
The selective oligomerization of ethene to linear alpha olefins is an attractive method for production of a wide range of key intermediates for the chemical industry. Current industrial processes are predominantly utilizing homogenous metal catalysts with a cocatalyst in organic solvents. Heterogeneous catalysts potentially offer a more environmentally friendly alternative and significant effort, both in academia and industry, has been put into the development of heterogeneous catalysts for the ethene oligomerization reaction.
In this thesis, nickel functionalized zeolites, silica, and metal-organic framework (MOF) catalysts have been investigated for the cocatalyst free ethene oligomerization reaction. Zeolites and MOFs are porous materials with a wide range of potential use and have numerous applications in catalysis. Different zeolites and MOFs have been investigated to understand the nature of the active site, reaction mechanism and the role of the support in the reaction. This thesis provides insights into role of the zeolites in the reaction and the dynamic nature of the nickel active site during the reaction. Kinetic, spectroscopic, and theoretical methods elucidate the nature of active and spectator nickel species in Ni-MOFs and opens new research opportunities to develop cocatalyst free MOF catalyst.
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Flatval, Jonas; Lundanes, Elsa; Wilson, Steven Ray Haakon; Olsbye, Unni; Nielsen, Claus Jørgen & Berg, Henriette Engen
(2020).
Retention of nitramines on silica-based reversed phase materials and UiO-66 MOF materials.
Universitetet i Oslo.
Vis sammendrag
Capturing and storing of CO2 can reduce the emissions of CO2 in the atmosphere. However, such facilities may emit amines that can be transformed into the potentially carcinogenic nitramines dimethylnitramine (DMA-NO2), monoethanolnitramine (MEA-NO2) and monomethylnitramine (MMA-NO2) which may be released into the environment. Presently, methods for trace determination of these compounds are lacking. The goal of the study was to find a material that can give sufficient retention to provide an enrichment of the nitramines before liquid chromatography electrospray ionization-mass spectrometry determination. The retention of the nitramines was examined on various C18 materials and the metal-organic frameworks UiO-66 and UiO-66 1,4-benzenedicarboxylate-NH2 (UiO-66-NH2), which were packed in 100 µm inner diameter columns. Of the tested materials, UiO-66-NH2 showed the highest retention factors for the nitramines. UiO-66-NH2 with 0.1% formic acid adjusted to pH 7 as mobile phase gave the best compromise of retention factors for DMA-NO2 and MEA-NO2, as the intended liquid chromatography-mass spectrometry method was evaluated for DMA-NO2 and MEA-NO2 only. MMA-NO2 had the highest retention factor on UiO-66-NH2 with 0.05% dibutylamine in the mobile phase. In conclusion, the retention factors achieved were in general higher on the UiO-66 materials than on the C18 materials. However, the retention obtained is probably not large enough to give limit of quantification down to 4 ng/L, albeit, not tested, due to extraordinary circumstances.
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Andersen, Kari Anne; Lundanes, Elsa; Berg, Henriette Engen; Wilson, Steven Ray Haakon; Chavan, Sachin Maruti & Lillerud, Karl Petter
[Vis alle 7 forfattere av denne artikkelen]
(2020).
UiO-66 metal-organic framework materials as stationary phases in liquid chromatography.
Universitetet i Oslo.
Vis sammendrag
The metal-organic frameworks (MOFs) UiO-66 and UiO-66-NH2 are composed of zirconium oxide nodes (Zr6O4(OH)4(CO2)12)and benzene-1,4-dicarboxylate (BDC) linkers for UiO-66, and the amino-functionalised linker 2-amino-benzene-1,4-dicarboxylate (ABDC) for UiO-66-NH2. UiO-66 and UiO-66-NH2 have large surface areas and a defined pore size and are thus attractive materials for chromatographic separations. The structure of these MOFs also meansseveral retention mechanisms could influence the separation simultaneously, making the retention of functionalised organic molecules on these materials challenging to predict. Hence, the aim of this thesiswas to investigate the chromatography of selected compounds on UiO-66 and UiO-66-NH2 in liquid chromatography (LC), to learn more about the potential applications of these UiO materials.UiO-66 and UiO-66-NH2 particles were packed into 100 μm inner diameter (ID) capillaries, and a simple LC-UV system was used for testing. Both materials rapidly (<30 min) packed into columns of circa 10 cm and provided pressures < 300 bar when used in LC systems. The efficiency (plate height) of the UiO-66-and UiO-66-NH2-columnswerefound to be 18 μm and 199 μm, respectively, using uracil asa modelanalyte. However, phosphate-containing analytes were found to have severe tailing. With an aqueous mobile phase, the retention of a selection of small hydrophilic molecules was found to increase with decreasing organic component in the mobile phase. The flow rate was also found to affect retention factors, with larger retention factors for lower flowrates. The effect of temperature in the range 25–55°C appeared to follow the expected trend of decreasing retention with increasing temperature for the chosen model substances, benzene, ethylbenzene and butylbenzene.Pore volume accessibility studies wereinconclusive. However, observations made strongly suggest that benzene, ethylbenzene, propylbenzene, butylbenzene, naphthalene and phenanthrene were able to access the pores of UiO-66.In conclusion, the UiO-66 MOF materials have chromatographic properties different from thoseof the more common LC separation materials, notably in the ability to retain small polar molecules. However, more research is needed to better understand the retention mechanisms of the materials and to single out application areas for these materials in LC.
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Solemsli, Bjørn Gading; Olsbye, Unni; Gunnæs, Anette Eleonora & Gutterød, Emil Sebastian
(2020).
A Study of Catalytic Pt Nanoparticles inside a Nano-porous Functionalized UiO MOF-matrix for CO2-Hydrogenation
.
Universitetet i Oslo.
Vis sammendrag
Hydrogenation of carbon dioxide hasreceivedincreasingattentionin catalytic research the last decade as a sustainable alternativeforproducing high value chemicals thattodayare produced fromfossil fuels. The aim of this thesis has been two-fold: First, to study Pt nanoparticles formed in various UiO-66 and -67 metal-organic frameworks (MOFs) by Transmission Electron Microscopy (TEM), and second, to study the Pt-containing MOFs as catalysts for the CO2hydrogenation reaction.Three Zr-based UiO-66 MOF and nineUiO-67 MOF samples containing different amountsof functionalized linkers were impregnated withdifferent amounts ofK2PtCl4and reduced in H2at 350 ̊C for 4 hours to form Pt nanoparticles embedded in the MOF matrix.The samples were then testedin a H2/CO2feed at 8 bar and 170 ̊Cfor the hydrogenation reaction. After testing,TEMwas used to investigate the formation of Pt nanoparticles andtheir relationship with the surrounding MOF structure.
The study revealed that, despite variable the linkers in the MOF,the conversion of CO2isdominated bythe reverse water-gas shift reaction,suggestingthat the linkers donot partakethe reactions mechanisms. Analysis usingTEMrevealedthat the Pt nanoparticles grow independently of its surroundings inside the MOFs with no observable growth relationshipwith the MOF. The nanoparticles are seen to grow into octahedral crystals that are larger than the pores in the framework. Samples with different amountsof missing linker type defects show that the presence of open Zr-node sitesenhances the selectivity towards methanol. A sample of Pt-functionalized UiO-67 with 10% [2,2’-bipyridine]5,5’-dicaboxylicacidlinker was oxidised toinduce missing linkerdefects post synthetically. After reduction in H2at 350 ̊C for 4 hours, the sample was oxidized in situin synthetic air for three different time spans. Careful analysis with N2-adsroption and TEM revealedthat the structure of the MOF deteriorates and loses accessible surface area with increasing timeon steam, while keeping the dispersion of the Pt nanoparticles. PXRD analysis revealedthe formation of tetragonal ZrO2. Extensive testsfrom 1-30 bar and 170-375 ̊C reveal a lower conversion and higher selectivity towards methanol for a fully calcined sample, indicating that the Zr-nodes behave similarlyto non-MOF ZrO2supports. Transient kinetic studies of the parent UiO-67 sample revealedthat the sample behaves similarlytopreviously studied systemsby Gutterød et al., and showed the presence of an inverse kinetic isotope effect for methane and methanolformation upon H2/D2exchange.
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Sannes, Johnny Andreas; Olsbye, Unni; Kalantzopoulos, Georgios N. & Arstad, Bjørnar
(2020).
CO2 adsorption and characterization of tailor-made metal-organic frameworks.
Universitetet i Oslo.
Vis sammendrag
In this work, the 𝐶𝑂2adsorption capacityof chemically interesting metal-organic frameworks (MOFs) have been investigated. The MOFs have been characterized using standard inorganic/organic characterization tools such as pXRD, TGA, liquidand solid state NMR, SEM-EDS, static anddynamic gas adsorption.Potentially strong adsorption sites on the Pt–Zr interface was investigated by the use of TAP. The isosteric heat of adsorption have been estimated for UiO –67 as a function of pretreatment.A comparison of the isosteric heat of adsorption determined by the use of static and dynamic gas adsorption studies have been made.A two-step adsorption mechanismin the N2adsorption isotherm was observed for UiO –67 in the low pressure regime (𝑝𝑝0<0.005). The observed adsorption isothermshow resemblance to that of MOF –808, however occurring at a much lower pressure.UiO –67 and UiO –67 type MOFs have been investigated by the use of ss –NMR. A major effort was made towards the assignment of the peaks in therecorded1H and 13C spectrum of UiO –67. The work was leading to the hopeful elucidation of adsorption sites and adsorption orientations, however due to time constraint only the groundworkhave been performed.