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SMN,
Catalysis,
Energy
Publications
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Aunan, Erlend; Gerz, Isabelle; Lillerud, Karl Petter; DeBeer, Serena & Olsbye, Unni
(2025).
Histidine–Copper Site Variability in UiO-66: Monitoring Synthetic Intricacy with EPR Spectroscopy.
Chemistry of Materials.
ISSN 0897-4756.
37(19),
p. 7648–7655.
doi:
10.1021/acs.chemmater.5c01005.
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Bioinspired design of catalysts aims to harness natural motifs observed in enzymatic systems to develop more efficient catalysts for industrial applications. One particularly inspiring group of enzymes─monooxygenases─demonstrate the highly efficient partial oxidations of substrates, such as the conversion of methane to methanol, a process that is highly sought after in industrial chemistry. In this study, we explore the use of zirconium-based metal–organic framework UiO-66, synthesized with open zirconium sites, to support copper–histidine complexes of varying geometries and speciation. Through the application of EPR spectroscopy, we identified three distinct copper species within the framework. The mole fractions of these copper species varied depending on the histidine loading, suggesting a tunable system with potential implications for catalytic performance. Without histidine loading, copper was found to bind scarcely to the defective site. With histidine, however, copper retention was improved. Two different species formed, of which one resembles the pMMO CuB site. Our findings lay the groundwork for further exploration and development of advanced catalysts using bioinspired design and cutting-edge MOF-characterization techniques.
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Aunan, Erlend; Finelli, Valeria; Prodinger, Sebastian; Cao, Ning; Garetto, Beatrice & Deplano, Gabriele
[Show all 13 contributors for this article]
(2024).
Partial oxidation of cyclohexene over histidine-modified Cu-UiO-66 under aerobic conditions.
Journal of Catalysis.
ISSN 0021-9517.
438.
doi:
10.1016/j.jcat.2024.115722.
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Enzyme-inspired catalysis is an attractive approach for developing selective hydrocarbon partial oxidation processes. Here, histidine was introduced into defective UiO-66 metal–organic framework by ligand exchange, followed by Cu(II) ion insertion. Density functional theory modeling combined with X-ray Absorption spectroscopy revealed that Cu(II) has a higher affinity for open Zr-O node sites than for histidine, leading to a series of materials where Cu(II) ions are predominantly anchored to the Zr6O4(OH)4 nodes, while only minority fractions of Cu(II) are anchored to histidine. Catalytic testing for aerobic cyclohexene oxidation with tert-butyl hydroperoxide (t-BuOOH) in trifluorotoluene solution at 25 °C showed activity for cyclohexene oxidation to cyclohexenol and cyclohexenone, with high selectivity. Benchmark tests revealed that Cu and t-BuOOH are both essential for the reaction, yet t-BuOOH consumption was far inferior to product formation rates, suggesting a radical reaction pathway involving O2.
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Gerz, Isabelle; Aunan, Erlend; Finelli, Valeria; Rasheed, Mouhammad Abu; Deplano, Gabriele & Pupo, Rafael Cortez Sgroi
[Show all 15 contributors for this article]
(2024).
Enabling a bioinspired N,N,N-copper coordination motif through spatial control in UiO-67: synthesis and reactivity.
Dalton Transactions.
ISSN 1477-9226.
53,
p. 8141–8153.
doi:
10.1039/d3dt03096b.
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Metal–organic frameworks (MOFs) featuring zirconium-based clusters are widely used for the development of functionalized materials due to their exceptional stability. In this study, we report the synthesis of a novel N,N,N-ligand compatible with a biphenyl dicarboxylic acid-based MOF. However, the resulting copper(I) complex exhibited unexpected coordination behaviour, lacking the intended trifold coordination motif. Herein, we demonstrate the successful immobilization of a bioinspired ligand within the MOF, which preserved its crystalline and porous nature while generating a well-defined copper site. Comprehensive spectroscopic analyses, including X-ray absorption, UV/Vis, and infrared spectroscopy, were conducted to investigate the copper site and its thermal behaviour. The immobilized ligand exhibited the desired tridentate coordination to copper, providing access to a coordination motif otherwise unattainable. Notably, water molecules were also found to coordinate to copper. Upon heating, the copper centre within the MOF exhibited reversible dehydration, suggesting facile creation of open coordination sites. Furthermore, the copper site displayed reduction at elevated temperatures and subsequent susceptibility to oxidation by molecular oxygen. Lastly, both the molecular complexes and the MOF were evaluated as catalysts for the oxidation of cyclohexane using hydrogen peroxide. This work highlights the successful immobilization of a bioinspired ligand in a zirconium-based MOF, shedding light on the structural features, thermal behaviour, and catalytic potential of the resulting copper sites.
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Poschmann, Mirjam Patricia Margarete; Lillerud, Karl Petter & Stock, Norbert
(2023).
Acidic Properties of Known and New COOH-Functionalized M(IV) Metal-Organic Frameworks.
Chemistry - A European Journal.
ISSN 0947-6539.
29(48).
doi:
10.1002/chem.202301760.
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Abstract Herein, we report two new COOH‐functionalized metal‐organic frameworks (MOFs) of composition [M 6 O 4 (OH) 6 (PMA) 2 (H 2 PMA)]×H 2 O, M=Zr, Hf), denoted CAU‐61, synthesized by using pyromellitic acid (H 4 PMA), a tetracarboxylic acid, as the linker and acetic acid as the solvent. The structure was determined from powder X‐ray diffraction data and one‐dimensional inorganic building units are connected through tetracarboxylate as well as dicarboxylate linker molecules, resulting in highly stable microporous framework structures with limiting and maximum pore diameter of ∼3.6 and ∼5.0 Å, respectively, lined with −COOH groups. Thermal stabilities of up to 400 °C in air, chemical stability in water at pH 1 to 12 and water uptake of 17 mol/mol prompted us to study the proton exchange of the μ 2 ‐OH, μ 3 ‐OH of the IBU and −COOH groups of the linker by titration with LiOH. Comparison of the p K a values with three UiO‐66 derivatives confirms distinct p K a value ranges and trends for the different acidic protons. Furthermore, the preparation of Zr−CAU‐61 membranes and first results on permeation of dyes and ions in aqueous solutions are presented.
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Xie, Jingxiu; Firth, Daniel Sean; Lanzac, Tomas Cordero; Airi, Alessia; Negri, Chiara & Øien-Ødegaard, Sigurd
[Show all 9 contributors for this article]
(2022).
MAPO-18 Catalysts for the Methanol to Olefins Process: Influence of Catalyst Acidity in a High-Pressure Syngas (CO and H2) Environment.
ACS Catalysis.
12,
p. 1520–1531.
doi:
10.1021/acscatal.1c04694.
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The transition from integrated petrochemical complexes toward decentralized chemical plants utilizing distributed feedstocks calls for simpler downstream unit operations. Less separation steps are attractive for future scenarios and provide an opportunity to design the next-generation catalysts, which function efficiently with effluent reactant mixtures. The methanol to olefins (MTO) reaction constitutes the second step in the conversion of CO2, CO, and H2 to light olefins. We present a series of isomorphically substituted zeotype catalysts with the AEI topology (MAPO-18s, M = Si, Mg, Co, or Zn) and demonstrate the superior performance of the M(II)-substituted MAPO-18s in the conversion of MTO when tested at 350 °C and 20 bar with reactive feed mixtures consisting of CH3OH/CO/CO2/H2. Co-feeding high pressure H2 with methanol improved the catalyst activity over time, but simultaneously led to the hydrogenation of olefins (olefin/paraffin ratio < 0.5). Co-feeding H2/CO/CO2/N2 mixtures with methanol revealed an important, hitherto undisclosed effect of CO in hindering the hydrogenation of olefins over the Brønsted acid sites (BAS). This effect was confirmed by dedicated ethene hydrogenation studies in the absence and presence of CO co-feed. Assisted by spectroscopic investigations, we ascribe the favorable performance of M(II)APO-18 under co-feed conditions to the importance of the M(II) heteroatom in altering the polarity of the M–O bond, leading to stronger BAS. Comparing SAPO-18 and MgAPO-18 with BAS concentrations ranging between 0.2 and 0.4 mmol/gcat, the strength of the acidic site and not the density was found to be the main activity descriptor. MgAPO-18 yielded the highest activity and stability upon syngas co-feeding with methanol, demonstrating its potential to be a next-generation MTO catalyst.
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Samperisi, Laura; Jaworski, Aleksander; Kaur, Gurpreet; Lillerud, Karl Petter; Zou, Xiaodong & Huang, Zhehao
(2021).
Probing Molecular Motions in Metal-Organic Frameworks by Three-Dimensional Electron Diffraction.
Journal of the American Chemical Society.
ISSN 0002-7863.
143(43),
p. 17947–17952.
doi:
10.1021/jacs.1c08354.
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Flexible metal–organic frameworks (MOFs) are known for their vast functional diversities and variable pore architectures. Dynamic motions or perturbations are among the highly desired flexibilities, which are key to guest diffusion processes. Therefore, probing such motions, especially at an atomic level, is crucial for revealing the unique properties and identifying the applications of MOFs. Nuclear magnetic resonance (NMR) and single-crystal X-ray diffraction (SCXRD) are the most important techniques to characterize molecular motions but require pure samples or large single crystals (>5 × 5 × 5 μm3), which are often inaccessible for MOF synthesis. Recent developments of three-dimensional electron diffraction (3D ED) have pushed the limits of single-crystal structural analysis. Accurate atomic information can be obtained by 3D ED from nanometer- and submicrometer-sized crystals and samples containing multiple phases. Here, we report the study of molecular motions by using the 3D ED method in MIL-140C and UiO-67, which are obtained as nanosized crystals coexisting in a mixture. In addition to an ab initio determination of their framework structures, we discovered that motions of the linker molecules could be revealed by observing the thermal ellipsoid models and analyzing the atomic anisotropic displacement parameters (ADPs) at room temperature (298 K) and cryogenic temperature (98 K). Interestingly, despite the same type of linker molecule occupying two symmetry-independent positions in MIL-140C, we observed significantly larger motions for the isolated linkers in comparison to those reinforced by π–π stacking. With an accuracy comparable to that of SCXRD, we show for the first time that 3D ED can be a powerful tool to investigate dynamics at an atomic level, which is particularly beneficial for nanocrystalline materials and/or phase mixtures.
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Aunan, Erlend; Affolter, Chris W.; Olsbye, Unni & Lillerud, Karl Petter
(2021).
Modulation of the Thermochemical Stability and Adsorptive Properties of MOF-808 by the Selection of Non-structural Ligands.
Chemistry of Materials.
ISSN 0897-4756.
33(4),
p. 1471–1476.
doi:
10.1021/acs.chemmater.0c04823.
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Metal–organic frameworks (MOFs) have been heavily researched due to their porous and crystalline nature. Because of this, MOFs are enticing materials for fields as diverse as gas separation and purification, water harvesting, and heterogeneous catalysis. Within most potential applications, it is critical for the material to remain unchanged when operating over prolonged periods and/or at elevated temperatures. Therefore, thermal stability is crucial in order to utilize MOFs industrially. In this article, we present a method to thermally stabilize MOF-808 by employing post-synthetic functionalization to incorporate benzoate moieties into its framework. We further describe how this incorporation changes the MOFs’ physicochemical properties (i.e., surface area, gas-adsorptive behavior, and crystallographic structure). The materials described herein are well characterized and provide novel options for the design of stable catalysts and adsorbents for future technologies.
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Thoresen, Eirik Mydske; Øien-Ødegaard, Sigurd; Kaur, Gurpreet; Tilset, Mats; Lillerud, Karl Petter & Amedjkouh, Mohamed
(2020).
Strongly visible light-absorbing metal-organic frameworks functionalized by cyclometalated ruthenium(ii) complexes.
RSC Advances.
10(15),
p. 9052–9062.
doi:
10.1039/c9ra06984d.
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Four different ruthenium(II) complexes were incorporated into the metal–organic framework (MOF) UiO-67 using three different synthetic strategies: premade linker synthesis, postsynthetic functionalization, and postsynthetic linker exchange. One of these complexes was of the type (N–N)3Ru2+, and three of the complexes were of the type (N–N)2(N–C)Ru+, where N–N is a bipyridine-type ligand and N–C is a cyclometalated phenylpyridine-type ligand. The resulting materials were characterized by PXRD, SC-XRD (the postsynthetic functionalization MOFs), N2 sorption, TGA-DSC, SEM, EDS, and UV-Vis spectroscopy, and were digested in base for subsequent 1H NMR analysis. The absorption profiles of the MOFs that were functionalized with cyclometalated Ru(II) complexes extend significantly further into the visible region of the spectrum compared to the absorption profiles of the MOFs that were functionalized with the non-cyclometalated reference, (N–N)3Ru2+.
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Øien-Ødegaard, Sigurd & Lillerud, Karl Petter
(2020).
Twinning in Zr-Based Metal-Organic Framework Crystals.
Chemistry.
2(3),
p. 777–786.
doi:
10.3390/chemistry2030050.
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Ab initio structure determination of new metal-organic framework (MOF) compounds is generally done by single crystal X-ray diffraction, but this technique can yield incorrect crystal structures if crystal twinning is overlooked. Herein, the crystal structures of three Zirconium-based MOFs, that are especially prone to twinning, have been determined from twinned crystals. These twin laws (and others) could potentially occur in many MOFs or related network structures, and the methods and tools described herein to detect and treat twinning could be useful to resolve the structures of affected crystals. Our results highlight the prevalence (and sometimes inevitability) of twinning in certain Zr-MOFs. Of special importance are the works of Howard Flack which, in addition to fundamental advances in crystallography, provide accessible tools for inexperienced crystallographers to take twinning into account in structure elucidation.
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Øien-Ødegaard, Sigurd; Bazioti, Kalliopi; Redekop, Evgeniy; Prytz, Øystein; Lillerud, Karl Petter & Olsbye, Unni
(2020).
A toroidal Zr70 oxysulfate cluster and its diverse packing structures.
Angewandte Chemie International Edition.
ISSN 1433-7851.
59,
p. 21397–21402.
doi:
10.1002/anie.202010847.
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Herein, we report the discovery of a toroidal inorganic cluster of zirconium(IV) oxysulfate of unprecedented size with the formula Zr70(SO4)58(O/OH)146⋅x(H2O) (Zr70), which displays different packing of ring units and thus several polymorphic crystal structures. The ring measures over 3 nm across, has an inner cavity of 1 nm and displays a pseudo‐10‐fold rotational symmetry of Zr6 octahedra bridged by an additional Zr in the outer rim of the ring. Depending on the co‐crystallizing species, the rings form various crystalline phases in which the torus units are connected in extended chain and network structures. One phase, in which the ring units are arranged in layers and form one‐dimensional channels, displays high permanent porosity (BET surface area: 241 m2 g−1), and thus demonstrates a functional property for potential use in, for example, adsorption or heterogeneous catalysis.
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Kømurcu, Mustafa; Lazzarini, Andrea; Kaur, Gurpreet; Borfecchia, Elisa; Øien-Ødegaard, Sigurd & Gianolio, Diego
[Show all 9 contributors for this article]
(2020).
Co-catalyst free ethene dimerization over Zr-based metal-organic framework (UiO-67) functionalized with Ni and bipyridine.
Catalysis Today.
ISSN 0920-5861.
doi:
10.1016/j.cattod.2020.03.038.
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Ni functionalized metal organic frameworks (MOF) are promising heterogeneous ethene dimerization catalysts. Activities comparable to or higher than Ni-aluminosilicates have been reported in literature. However, unlike the Ni-aluminosilicates, those Ni-MOFs require a large excess of co-catalyst to initiate the dimerization process and some catalysts generate polymers which lead to catalyst deactivation. Herein, we report a series of Ni(II) and 2,2′-bipyridine-5,5′-dicarboxylate (bpy) functionalized UiO-67 MOF that catalyze the ethene dimerization reaction co-catalyst free. The catalysts were active for ethene dimerization (up to 850 mg butene gcat−1 h−1) after activation at 300 °C in 10 % O2 for 360 min and subsequent exposure to flowing ethene (P(ethene) =26 bar, 250 °C) for 240 min. The catalysts yielded up to 6 % conversion with 99 % selectivity to linear 1- and 2-butenes, which formed in non-equilibrated ratios. Overall, the test data indicate that all three linear butenes are formed on a single active site, in accordance with the Cossee-Arlman mechanism. Ex situ XAS and CO FT-IR spectroscopy studies point towards Ni monomers or, plausibly, low-nuclearity Ni-multimers, docked at bpy linkers with Ni-Ni distances > 4 Å, as the main active site for the ethene dimerization reaction.
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Molino, Andrea; Holzinger, J.; Lukaszuk, Katarzyna Anna; Rojo-Gama, Daniel; Gunnæs, Anette Eleonora & Skibsted, J.
[Show all 11 contributors for this article]
(2019).
Synthesis of ZSM-23 (MTT) zeolites with differentcrystal morphology and intergrowths: effects onthe catalytic performance in the conversion ofmethanol to hydrocarbons.
Catalysis Science & Technology.
ISSN 2044-4753.
9(23),
p. 6782–6792.
doi:
10.1039/c9cy01068h.
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A series of zeolite ZSM-23 samples prepared with different organic structure-directing agents, gave rise to crystalline phases, which show a large variety of particle dimensions. A detailed analysis of the structure of these materials revealed the presence of different levels of stacking fault defects when using different recipes. The effect of crystal size and morphology was investigated in the methanol to hydrocarbon reaction at 400 °C, showing a predominant production of hydrocarbons in the range C3–C6+ and negligible amount of aromatics (<3%) in all cases. More importantly, we show that methanol conversion and catalytic lifetime are strongly influenced by small differences in crystal size and morphology due to a preferential crystal growth along the microchannel direction.
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Gutterød, Emil Sebastian; Lazzarini, Andrea; Fjermestad, Torstein; Kaur, Gurpreet; Manzoli, Maela & Bordiga, Silvia
[Show all 12 contributors for this article]
(2019).
Hydrogenation of CO2 to Methanol by Pt Nanoparticles
Encapsulated in UiO-67: Deciphering the Role of the Metal−Organic
Framework.
Journal of the American Chemical Society.
ISSN 0002-7863.
142(2),
p. 999–999.
doi:
10.1021/jacs.9b10873.
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Metal-organic frameworks (MOFs) show great prospect as catalysts and catalyst support materials. Yet, studies that address their dynamic, kinetic and mechanistic role in target reactions are scarce. In this study, an exceptionally stable MOF catalyst consisting of Pt nanoparticles (NPs) embedded in a Zr-based UiO-67 MOF was subject to steady-state and transient kinetic studies involving H/D and 13C /12C exchange, coupled with operando infrared spectroscopy and density functional theory (DFT) modeling, targeting methanol formation from CO2/H2 feeds at 170 C and 1-8 bar pressure. The study revealed that methanol is formed at the interface between the Pt NPs and defect Zr nodes, via formate species attached to the Zr nodes. Methanol formation is mechanistically separated from the formation of co-products CO and methane, except for hydrogen activation on the Pt NPs. Careful analysis of transient data revealed that the number of intermediates was higher than the number of open Zr sites in the MOF lattice around each Pt NP. Hence, additional Zr sites must be available to formate formation. DFT modelling revealed that Pt NP growth is sufficiently energetically favored to enable displacement of linkers and creation of open Zr sites during pretreatment. However, linker displacement during formate formation is energetically disfavored, in line with the excellent catalyst stability observed experimentally. Overall, the study provides firm evidence that methanol is formed at the interface of Pt NPs and linker-deficient Zr6O8 nodes resting on the Pt NP surface.
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Bugaev, Aram L.; Skorynina, Alina A.; Braglia, Luca; Lomachenko, Kirill A.; Guda, Alexander & Lazzarini, Andrea
[Show all 11 contributors for this article]
(2019).
Evolution of Pt and Pd species in functionalized UiO-67 metal-organic frameworks.
Catalysis Today.
ISSN 0920-5861.
336,
p. 33–39.
doi:
10.1016/j.cattod.2019.03.054.
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Functionalization of metal-organic frameworks (MOFs) with noble metals is a promising way for producing new versatile catalysts that will combine the outstanding porosity and specific surface area of MOFs with high catalytic activity of metals. Here, we present a comparative study of two metal-organic frameworks with UiO-67 topology, functionalized with palladium and platinum moieties. The initial structure of all studied samples contained palladium or platinum atoms grafted into MCl2bpydc (M = Pd, Pt) linkers of MOFs. The materials were further activated by heating in inert and H2-containing atmospheres. Both Pd- and Pt- functionalized materials exhibited high thermal stability upon heating in these atmospheres. The evolution of Pt and Pd species during the activation procedure was monitored by in situ time-resolved X-ray absorption near-edge structure (XANES) spectroscopy. We applied multivariate curve resolution alternating least squares (MCR-ALS) approach to XANES to unravel the intermediates which can be formed during the activation procedure. For UiO-67-Pd, only simple one-step transformation from PdCl2bpydc to Pd nanoparticles (NPs) was observed. For UiO-67-Pt, two additional intermediate states were observed, which behave differently depending on the activation procedure. Theoretical calculation of XANES spectra allowed us to suggest the 3D-atomic structures corresponding to each of the pure spectra determined by MCR-ALS. In addition, reaction enthalpies for different possible reaction routes were calculated within a density functional theory approach. Based on the experimental and theoretical results showed that Pd nanoparticles (NPs) tend to be formed in UiO-67-Pd samples irrespective of the activation procedure, while either Pt NPs or isolated PtII active sites, grafted in the MOF framework may be formed in UiO-67-Pt samples depending on the activation temperature and atmosphere.
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Velthoven, Niels Van; Waitschat, Steve; Chavan, Sachin Maruti; Liu, Pei; Smolders, Simon & Vercammen, Jannick
[Show all 11 contributors for this article]
(2019).
Single-site metal-organic framework catalysts for the oxidative coupling of arenes: Via C-H/C-H activation.
Chemical Science.
ISSN 2041-6520.
10(12),
p. 3616–3622.
doi:
10.1039/c8sc05510f.
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C–H activation reactions are generally associated with relatively low turnover numbers (TONs) and high catalyst concentrations due to a combination of low catalyst stability and activity, highlighting the need for recyclable heterogeneous catalysts with stable single-atom active sites. In this work, several palladium loaded metal–organic frameworks (MOFs) were tested as single-site catalysts for the oxidative coupling of arenes (e.g. o-xylene) via C–H/C–H activation. Isolation of the palladium active sites on the MOF supports reduced Pd(0) aggregate formation and thus catalyst deactivation, resulting in higher turnover numbers (TONs) compared to the homogeneous benchmark reaction. Notably, a threefold higher TON could be achieved for palladium loaded MOF-808 due to increased catalyst stability and the heterogeneous catalyst could efficiently be reused, resulting in a cumulative TON of 1218 after three runs. Additionally, the palladium single-atom active sites on MOF-808 were successfully identified by Fourier transform infrared (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy.
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Butova, Vera V.; Budnyk, Andriy P.; Charykov, Konstantin M.; Vetlitsyna-Novikova, Kristina S.; Bugaev, Aram L. & Guda, Alexander A.
[Show all 12 contributors for this article]
(2019).
Partial and complete substitution of the 1,4-benzenedicarboxylate linker in UiO-66 with 1,4-naphthalenedicarboxylate: Synthesis, characterization, and H2-adsorption properties.
Inorganic Chemistry.
ISSN 0020-1669.
58(2),
p. 1607–1620.
doi:
10.1021/acs.inorgchem.8b03087.
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Kaur, Gurpreet; Øien-Ødegaard, Sigurd; Lazzarini, Andrea; Chavan, Sachin Maruti; Bordiga, Silvia & Lillerud, Karl Petter
[Show all 7 contributors for this article]
(2019).
Controlling the Synthesis of Metal−Organic Framework UiO-67 by Tuning Its Kinetic Driving Force.
Crystal Growth & Design.
ISSN 1528-7483.
19(8),
p. 4246–4251.
doi:
10.1021/acs.cgd.9b00916.
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The successful synthesis of metal−organic framework (MOF) compounds relies on an intricate interplay between the components of the synthesis liquor at the given synthesis conditions. Herein, we explore the interdependence of modulator, linker, and solvent amounts in the synthesis of the Zr-based MOF, UiO-67. Our study suggests that control of linker vacancy defects in UiO-67 is feasible by tuning the ratios of these components, and that such control derives from recognizing the kinetic driving forces during MOF crystal growth. Importantly, we show that linker vacancy defects (and modulator molecules occupying linker sites) can be reduced by limiting the solvent amount to maintain a saturated concentration of linker throughout the synthesis. The method enables formation of UiO-67 with an ideal 1:1 ratio between Zr and the 4,4′-biphenyldicarboxylic acid linker, without surplus linker in the mother liquor or additional postsynthetic steps, and reduces the amount of dimethylformamide (DMF) solvent to less than 20% the amount in previously reported procedures.
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Rhauderwiek, Timo; Wolkersdorfer, Konrad; Øien-Ødegaard, Sigurd; Lillerud, Karl Petter; Wark, Michael & Stock, Norbert
(2018).
Crystalline and permanently porous porphyrin-based metal tetraphosphonates.
Chemical Communications.
ISSN 1359-7345.
54(4),
p. 389–392.
doi:
10.1039/c7cc07766a.
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Campo, Pablo Del; Beato, Pablo; Rey, Fernando; Navarro, Maria Teresa; Olsbye, Unni & Lillerud, Karl Petter
[Show all 7 contributors for this article]
(2018).
Influence of post-synthetic modifications on the composition, acidity and textural properties of ZSM-22 zeolite.
Catalysis Today.
ISSN 0920-5861.
299,
p. 120–134.
doi:
10.1016/j.cattod.2017.04.042.
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In this work, an extensive investigation of the preparation of a large body of desilicated ZSM-22 zeolites and their basic characterization is presented. We investigate the effects of the properties of the starting zeolite, and we employ mixtures of NaOH with CTAB or TBAOH as well as subsequent acid washings to create mesoporous zeolites. Scanning and transmission electron microscopy and nitrogen adsorption revealed that the crystal morphology of the starting zeolite appears to be the dominant parameter which influences the mesopore generation. Mesopores were effectively created within the rod-like commercial crystallites, whereas the thinner dimensions of the needle-shaped particles of the lab-made zeolite represent an obstacle for an intra-mesopore creation. The alkaline, surfactant-assisted or combined NaOH/TBAOH desilication methods resulted in mesopores with different shape and size from the commercial zeolite. The sequential acid washing generally resulted in increased micropore volume with respect to the desilicated samples. Elemental analysis showed that extra-framework Al species were generated upon the desilication treatments, which are eventually removed by the acid treatment. The acidity studied by FTIR demonstrated that this occurs without a marked modification of the Brønsted acidity, whereas the concentration of surface silanol hydroxyl groups is increased. The comparison between the total Al concentration and the amount of Al in acidic sites quantified by pyridine adsorption shows that the acidity was recovered after the acid washing and suggests that original non-acidic Al species in the starting materials may have a role in the formation of both Lewis and extra-framework species upon desilication.
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Campo, Pablo Del; Olsbye, Unni; Lillerud, Karl Petter; Svelle, Stian & Beato, Pablo
(2018).
Impact of post-synthetic treatments on unidirectional H-ZSM-22 zeolite catalyst: Towards improved clean MTG catalytic process.
Catalysis Today.
ISSN 0920-5861.
299,
p. 135–145.
doi:
10.1016/j.cattod.2017.05.011.
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In the present study, a series of H-ZSM-22 mesoporous catalysts resulting from three different desilication treatments (NaOH treatment, treatment using mixtures of NaOH/CTAB and using mixtures of NaOH/TBAOH) and sequential acid leaching over two different (commercial and lab-made) microporous ZSM-22, were tested in the conversion of methanol to hydrocarbons. The influence of the post-synthetic treatments on the catalytic lifetime and product distribution was examined. The influence of the starting catalysts on the change in the catalyst properties was also reflected in the catalytic behaviour. An increase of about 10 times in total methanol conversion capacity with respect to the untreated catalyst was reached after the CTAB/NaOH and acid treatment over the commercial material, whereas a 17-fold increase in conversion capacity was achieved for the lab-made catalysts treated with NaOH and acid. The yield towards the aromatic-free C5+ alkene fraction was slightly increased after the post-synthetic treatments, up to 58% of clean gasoline product precursors. The correlations between porosity, acidity and total conversion capacity suggested a more efficient use of the hierarchical catalyst particle as a result of a synergetic effect of mesopore formation, enhanced accessibility to the micropores and acid sites, and increased adsorption and transport properties. Mechanistic information extracted from the analysis of the C3/C2 and ethene/2M2B ratios, suggested that the improved catalyst properties allow a longer propagation of the olefin cycle with reaction time.
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Dyballa, Michael Martin; Pappas, Dimitrios; Borfecchia, Elisa; Beato, Pablo; Olsbye, Unni & Lillerud, Karl Petter
[Show all 8 contributors for this article]
(2018).
Tuning the material and catalytic properties of SUZ-4 zeolites for the conversion of methanol or methane.
Microporous and Mesoporous Materials.
ISSN 1387-1811.
265,
p. 112–122.
doi:
10.1016/j.micromeso.2018.02.004.
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This work describes the synthesis and investigation of improved SUZ-4 catalysts (SZR framework) and their application in methanol-to-olefins and methane-to-methanol conversion. We report boron containing, dealuminated and desilicated SUZ-4 catalysts. Ammonia and pyridine probe molecules enabled the assignment of acid site densities to the 10-MR and 8-MR pores, respectively. The difference in between the theoretically expected and the for the probes accessible acid site density is a good descriptor for the accessibility of pores and acid sites. The access to the 8-MR SUZ-4 pores is sterically hindered by counter ions as well as extra framework aluminum (EFAl) species that account for up to 15% of the aluminum. Dealumination and desilication were successfully applied to optimize the diffusion properties and resulted in outstandingly high BET surface area, nSi/nAl-ratios and potassium exchange degrees. The improved accessibility led to an up to 2-fold increased MTO conversion capacity of the catalysts. Cu-exchanged SUZ-4 was applied in the selective oxidation of methane to methanol. By operando X-ray absorption spectroscopy (XAS) we showed that CuII ions are mainly coordinated in 2Al sites of 6-MR motifs and inhibited for redox-reactions.
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Rojo-Gama, Daniel; Mentel, Lukasz; Kalantzopoulos, Georgios N.; Pappas, Dimitrios; Dovgaliuk, Iurii & Olsbye, Unni
[Show all 11 contributors for this article]
(2018).
Deactivation of Zeolite Catalyst H-ZSM-5 during Conversion of Methanol to Gasoline: Operando Time- and Space-Resolved X-ray Diffraction.
The Journal of Physical Chemistry Letters.
9(6),
p. 1324–1328.
doi:
10.1021/acs.jpclett.8b00094.
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The deactivation of zeolite catalyst H-ZSM-5 by coking during the conversion of methanol to hydrocarbons was monitored by high-energy space- and time-resolved operando X-ray diffraction (XRD) . Space resolution was achieved by continuous scanning along the axial length of a capillary fixed bed reactor with a time resolution of 10 s per scan. Using real structural parameters obtained from XRD, we can track the development of coke at different points in the reactor and link this to a kinetic model to correlate catalyst deactivation with structural changes occurring in the material. The “burning cigar” model of catalyst bed deactivation is directly observed in real time.
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Atzori, Cesare; Shearer, Greig Charles; Maschio, Lorenzo; Civalleri, Bartolomeo; Bonino, Francesca & Lamberti, Carlo
[Show all 9 contributors for this article]
(2017).
Effect of Benzoic Acid as a Modulator in the Structure of UiO-66: An Experimental and Computational Study.
Journal of Physical Chemistry C.
ISSN 1932-7447.
121(17),
p. 9312–9324.
doi:
10.1021/acs.jpcc.7b00483.
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The identification and quantification of defects are undoubtedly thorough challenges in the characterization of “defect-engineered” metal–organic frameworks (MOFs). UiO-66, known for its exceptional stability and defect tolerance, has been a popular target for defect-engineering studies. Herein, we show that synthesizing UiO-66 in the presence of an excess of benzoic acid is a reliable method for obtaining UiO-66 samples with a very high concentration of missing-cluster defects, allowing one to modulate specific properties (i.e., surface area and hydrophobicity). This was elucidated by a multitechnique marriage of experimental and computational methods: a combination of PXRD, dissolution/1H NMR spectroscopy, and N2 sorption measurements was used to quantify the defect loading, while vibrational spectroscopies (FTIR and Raman) allowed us to unequivocally identify the defect structure by comparison with DFT-simulated spectra and visual analysis of the computed vibrational modes. © 2017 American Chemical Society
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Rojo-Gama, Daniel; Nielsen, Malte; Wragg, David; Dyballa, Michael Martin; Holzinger, Julian & Falsig, Hanne
[Show all 12 contributors for this article]
(2017).
A Straightforward Descriptor for the Deactivation of Zeolite Catalyst H-ZSM-5.
ACS Catalysis.
7(12),
p. 8235–8246.
doi:
10.1021/acscatal.7b02193.
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ZSM-5 is a widely used zeolite catalyst and is employed industrially for the methanol to gasoline (MTG) process. Even so, deactivation of ZSM-5 by coke formation constitutes a major technical and also fundamental challenge. We investigate the deactivation of a range of ZSM-5 catalysts through catalytic testing, physicochemical characterization, and powder X-ray diffraction (XRD). It is demonstrated that the unit cell changes upon deactivation. Periodic density functional theory is used to show that the change is induced by certain methyl substituted benzenes in the channel intersection in ZSM-5. This finding is corroborated by Rietveld refinement of XRD data obtained for deactivated catalysts. We are able to establish a direct correlation between the difference in the length of the a- and b-unit cell vectors and the total amount of coke, the remaining acidity, and the remaining surface area of the catalysts. This a- minus b-parameter is a straightforward descriptor that carries the essential information regarding the degree of deactivation of a ZSM-5 catalyst, and a routine measurement of a diffractogram of the catalyst can be used to quantitatively assess the degree of deactivation.
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Rojo-Gama, Daniel; Signorile, Matteo; Bonino, Francesca; Bordiga, Silvia; Olsbye, Unni & Lillerud, Karl Petter
[Show all 8 contributors for this article]
(2017).
Structure-deactivation relationships in zeolites during the methanol–to-hydrocarbons reaction: Complementary assessments of the coke content.
Journal of Catalysis.
ISSN 0021-9517.
351,
p. 33–48.
doi:
10.1016/j.jcat.2017.04.015.
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Catalyst deactivation during the methanol-to-hydrocarbons (MTH) reaction was investigated using five different commercially prepared microporous catalysts, including Mordenite, ZSM-22, ZSM-5, zeolite Beta and SAPO-34. The reaction was carried out in a fixed bed reactor at a constant feed rate per gram of catalyst. Deactivated and partially deactivated catalysts were obtained at increasing reaction times. The whole of the catalyst beds was characterized using nitrogen adsorption, thermogravimetric analysis, a dissolution-extraction protocol, and UV-Raman spectroscopy, focusing primarily on methods suitable for the quantification of the coke. The results illustrate that topology is the dominant parameter that influences not only catalyst lifetime and product distribution, but also the nature of the species causing the deactivation. For all catalyst topologies, when the entire catalyst bed is examined together, the micropore volume and BET surface area decrease more rapidly than total coke from TGA increases at short reaction times. In the materials with the more restricted access to the internal voids, such as ZSM-22 and SAPO-34, the loss of activity is to a large extent due to species which are soluble in dichloromethane and give rise to distinct features in the Raman spectra. For the Mordenite and Beta catalysts, which have larger pores comprising three dimensional networks, and to some extent for the ZSM-5 catalyst employed, the accumulation of more coke species which are insoluble in dichloromethane, presumably on the external surface of the zeolite crystals, is observed. This is linked to the appearance of more pronounced D and G bands in the Raman spectra, indicative of extended carbon species.
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Lukaszuk, Katarzyna Anna; Rojo-Gama, Daniel; Øien-Ødegaard, Sigurd; Lazzarini, Andrea; Berlier, Gloria & Bordiga, Silvia
[Show all 11 contributors for this article]
(2017).
Zeolite morphology and catalyst performance: Conversion of methanol to hydrocarbons over offretite.
Catalysis Science & Technology.
ISSN 2044-4753.
7(22),
p. 5435–5447.
doi:
10.1039/c7cy00996h.
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The synthesis, characterization and catalytic performance of offretite with four distinct crystal morphologies (oval, hexagonal, broccoli-like, and spherical) are presented. As a member of the ABC-6 family of zeolite structures, offretite is likely to form intergrowths which can affect its shape-selective properties. Herein, a combination of experiments (SC-XRD, PXRD, benzene uptake and the methanol-to-hydrocarbon conversion) allows the determination of the mechanism and fraction of twinning. It is demonstrated that the catalysts with the same crystal aspect ratio (AR = 3) yield product spectra dominated by C2–C4 aliphatics. Such product selectivity is associated with zeolites with an 8-ring channel system. Interestingly, a significant production of bulky aromatics is seen for the catalyst with the spherical morphology (AS = 1.1) which is a manifestation of the 12-ring pore system of the OFF framework topology. This constitutes the first report of this behavior. The particular display of product shape selectivity can be ascribed to the catalyst particle morphology.
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Rojo-Gama, Daniel; Etemadi, Samaneh; Kirby, Eliot; Lillerud, Karl Petter; Beato, Pablo & Svelle, Stian
[Show all 7 contributors for this article]
(2017).
Time- and space-resolved study of the Methanol to Hydrocarbons (MTH) reaction - influence of zeolite topology on deactivation patterns.
Faraday discussions.
ISSN 1359-6640.
197,
p. 421–446.
doi:
10.1039/c6fd00187d.
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Zeolites representing seven different topologies were subjected to life-time assessment studies as methanol to hydrocarbons (MTH) catalysts at 400 °C, P(MeOH) = 13 kPa and P(tot) = 100 kPa. The following topologies were studied: ZSM-22 (TON), ZSM-23 (MTT), IM-5 (IMF), ITQ-13 (ITH), ZSM-5 (MFI), mordenite (MOR) and beta (BEA). Two experimental approaches were used. In the first approach, each catalyst was tested at three different contact times, all giving 100% initial conversion. The life-time before conversion decreased to 50% at each contact time was measured and used to calculate critical contact times (i.e. the contact time needed to launch the autocatalytic MTH reaction) and deactivation rates. It was found that the critical contact time is strongly correlated with pore size: the smaller the pore size, the longer the critical contact time. The second experimental approach consisted of testing the catalysts in a double tube reactor with 100% initial conversion, and quenching the reaction after 4 consecutive times on stream, representing full, partial, and zero conversion. After quenching, the catalyst bed was divided into four segments, which were individually characterised for coke content (temperature-programmed oxidation) and specific surface area (N2 adsorption). The axial deactivation pattern was found to depend on pore size. With increasing pore size, the main source of coke formation changed from methanol conversion (1D 10-ring structures), to partly methanol, partly product conversion (3D 10-ring structures) and finally mainly product conversion (3D 12-ring structure). As a result, the methanol conversion capacity changed little with contact time for ZSM-5, while it increased with increasing contact time for the catalysts with smaller pore sizes, and decreased with increasing contact time for pore sizes larger than ZSM-5.
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Gutterød, Emil Sebastian; Øien-Ødegaard, Sigurd; Bossers, Koen; Nieuwelink, Anne-Eva; Manzoli, Maela & Braglia, Luca
[Show all 17 contributors for this article]
(2017).
CO2 Hydrogenation over Pt-Containing UiO-67 Zr-MOFs—The Base Case.
Industrial & Engineering Chemistry Research.
ISSN 0888-5885.
56(45),
p. 13206–13218.
doi:
10.1021/acs.iecr.7b01457.
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CO2 hydrogenation was carried out over Pt-containing
UiO-67 Zr-MOFs at T = 220−280 °C and ambient pressure, with H2/
CO2 = 0.2−9 and contact times, τ = 0.004−0.01 gcat·min·mL−1
. The
catalysts were characterized by XRD, N2 adsorption, FESEM, TEM and
HRTEM, Pt L3-edge XANES and EXAFS, dissolution-NMR, CO
chemisorption, IR spectroscopy, and TGA. A positive correlation was
observed between the degree of Pt reduction and CO2 conversion.
Contact time variation experiments showed that CO is a primary product
of reaction, while CH4 is a secondary product. Testing of catalyst crystals
with 0.15 and 2.0 μm crystal size, respectively, revealed no influence of
diffusion on the reaction rate. Comparison to a conventional Pt/SiO2
catalyst showed very similar activation energy, with Eapp = 50 ± 3 kJ·
mol−1
. However, the turnover frequency over Pt/SiO2 was significantly lower, and Pt/SiO2 did not yield methane as a product.
The Pt-containing UiO-67 Zr-MOF catalyst showed stable activity during 60 h of testing.
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Pappas, Dimitrios; Borfecchia, Elisa; Dyballa, Michael Martin; Pankin, Ilia A.; Lomachenko, Kirill A. & Martini, Andrea
[Show all 16 contributors for this article]
(2017).
Methane to methanol: structure-activity relationships for Cu-CHA.
Journal of the American Chemical Society.
ISSN 0002-7863.
139(42),
p. 14961–14975.
doi:
10.1021/jacs.7b06472.
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Cu-exchanged zeolites possess active sites that are able to cleave the C–H bond of methane at temperatures ≤200 °C, enabling its selective partial oxidation to methanol. Herein we explore this process over Cu-SSZ-13 materials. We combine activity tests and X-ray absorption spectroscopy (XAS) to thoroughly investigate the influence of reaction parameters and material elemental composition on the productivity and Cu speciation during the key process steps. We find that the CuII moieties responsible for the conversion are formed in the presence of O2 and that high temperature together with prolonged activation time increases the population of such active sites. We evidence a linear correlation between the reducibility of the materials and their methanol productivity. By optimizing the process conditions and material composition, we are able to reach a methanol productivity as high as 0.2 mol CH3OH/mol Cu (125 μmol/g), the highest value reported to date for Cu-SSZ-13. Our results clearly demonstrate that high populations of 2Al Z2CuII sites in 6r, favored at low values of both Si:Al and Cu:Al ratios, inhibit the material performance by being inactive for the conversion. Z[CuIIOH] complexes, although shown to be inactive, are identified as the precursors to the methane-converting active sites. By critical examination of the reported catalytic and spectroscopic evidence, we propose different possible routes for active-site formation.
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Øien-Ødegaard, Sigurd; Shearer, Greig Charles; Wragg, David & Lillerud, Karl Petter
(2017).
Pitfalls in metal-organic framework crystallography: Towards more accurate crystal structures.
Chemical Society Reviews.
ISSN 0306-0012.
46(16),
p. 4867–4876.
doi:
10.1039/c6cs00533k.
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Molino, Andrea; Lukaszuk, Katarzyna Anna; Rojo-Gama, Daniel; Lillerud, Karl Petter; Olsbye, Unni & Bordiga, Silvia
[Show all 8 contributors for this article]
(2017).
Conversion of methanol to hydrocarbons over zeolite ZSM-23 (MTT): Exceptional effects of particle size on catalyst lifetime.
Chemical Communications.
ISSN 1359-7345.
53,
p. 6816–6819.
doi:
10.1039/c6cc10118f.
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A variety of synthetic procedures have been used to obtain zeolite ZSM-23 (MTT) catalysts with crystallite sizes ranging from the micrometer to nanometer scale. When the acidic zeolite is used as catalyst for the Methanol to hydrocarbons (MTH) reaction, the catalytic lifetime is dramatically influenced by the crystallite shape and size.
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Shearer, Greig Charles; Vitillo, Jenny G.; Bordiga, Silvia; Svelle, Stian; Olsbye, Unni & Lillerud, Karl Petter
(2016).
Functionalizing the Defects: Post Synthetic Ligand Exchange in the Metal Organic Framework UiO-66.
Chemistry of Materials.
ISSN 0897-4756.
28(20),
p. 7190–7193.
doi:
10.1021/acs.chemmater.6b02749.
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Reinsch, Helge; Waitschat, Steve; Chavan, Sachin Maruti; Lillerud, Karl Petter & Stock, Norbert
(2016).
A Facile “Green” Route for Scalable Batch Production and Continuous Synthesis of Zirconium MOFs.
European Journal of Inorganic Chemistry (EurJIC).
ISSN 1434-1948.
2016(27),
p. 4490–4498.
doi:
10.1002/ejic.201600295.
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Øien-Ødegaard, Sigurd; Bouchevreau, Boris; Hylland, Knut Tormodssønn; Wu, Lianpao; Blom, Richard & Grande, Carlos Adolfo
[Show all 9 contributors for this article]
(2016).
UiO-67-type Metal-Organic Frameworks with Enhanced Water Stability and Methane Adsorption Capacity.
Inorganic Chemistry.
ISSN 0020-1669.
55(5),
p. 1986–1991.
doi:
10.1021/acs.inorgchem.5b02257.
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The structure and properties of two new UiO-67-type metal–organic frameworks, along with their linker synthesis and powder and single crystal synthesis, are presented. The new MOFs, UiO-67-Me and UiO-67-BN, are based on 3,3′-dimethylbiphenyl and 1,1′-binaphthyl linker scaffolds, and show a much higher stability to water than the thoroughly investigated UiO-67, which is based on the biphenyl scaffold. On the basis of structure models obtained from single crystal X-ray diffraction, it is seen that these linkers are partly shielding the Zr cluster. The new materials have higher density than UiO-67, but show a higher volumetric adsorption capacity for methane. UiO-67-BN exhibits excellent reversible water sorption properties, and enhanced stability to aqueous solutions over a wide pH range; it is to the best of our knowledge the most stable Zr-MOF that is isostructural to UiO-67 in aqueous solutions.
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Shearer, Greig Charles; Chavan, Sachin Maruti; Bordiga, Silvia; Svelle, Stian; Olsbye, Unni & Lillerud, Karl Petter
(2016).
Defect Engineering: Tuning the Porosity and Composition of the Metal-Organic Framework UiO-66 via Modulated Synthesis.
Chemistry of Materials.
ISSN 0897-4756.
28(11),
p. 3749–3761.
doi:
10.1021/acs.chemmater.6b00602.
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Braglia, L; Borfecchia, E; Lomachenko, KA; Øien-Ødegaard, Sigurd; Lillerud, Karl Petter & Lamberti, C
(2016).
XAS on Rh and Ir metal sites in post synthetically functionalized UiO-67 Zirconium MOFs.
Journal of Physics: Conference Series (JPCS).
ISSN 1742-6588.
712(1).
doi:
10.1088/1742-6596/712/1/012053.
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Reinsch, Helge; Bueken, Bart; Vermoortele, Frederik; Stassen, Ivo; Lieb, Alexandra & Lillerud, Karl Petter
[Show all 7 contributors for this article]
(2015).
Green synthesis of zirconium-MOFs.
CrysteEngComm.
17(22),
p. 4070–4074.
doi:
10.1039/c5ce00618j.
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The synthesis of Zr-MOFs under green, industrially feasible conditions was investigated. Two new compounds with bcu-topology and the fluorinated analogue of UiO-66 exhibiting fcu-topology were obtained and characterised. All products exhibit permanent porosity. In the bcu-frameworks the interaction with sulfate anions apparently induces an unusual eightfold connectivity of the Zr cluster.
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Teketel, Shewangizaw; Lundegaard, Lars Fahl; Skistad, Wegard; Chavan, Sachin Maruti; Olsbye, Unni & Lillerud, Karl Petter
[Show all 8 contributors for this article]
(2015).
Morphology-induced shape selectivity in zeolite catalysis.
Journal of Catalysis.
ISSN 0021-9517.
327,
p. 22–32.
doi:
10.1016/j.jcat.2015.03.013.
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Zeolites are crystalline aluminosilicates that are widely used as shape-selective catalysts in the refinery and petrochemical industries. By synthesizing a series of structurally related zeolite catalyst and applying them in the industrially relevant conversion of methanol to hydrocarbons, new and extended understanding of the concept of shape selectivity has been reached. We have analyzed the relationship between particle morphology and pore system for catalysts having both small- and medium-sized pores using microscopy and diffraction, as well as performing extensive standard characterization. Two instances of preferential exposure of certain crystal facets, favoring access to one pore system over the other, have been found. Zeolites ZSM-57 (MFS) and SUZ-4 (SZR) both have both 8- and 10-ring channels. MFS prefers a plate-like or nanosheet-type morphology, where the 10-ring channels are perpendicular to the plates/sheets. This leads to favorable diffusion properties and a pronounced deactivation resistance. For SZR, needle-like crystals with high aspect ratio are preferred. In this instance, the sides of the needles are covered by the 8-ring pore openings, whereas the 10-ring pore openings are only exposed at the ends of the needles. This leads to unexpected product selectivity, as the material behaves essentially as an 8-ring catalyst. We argue that it should be possible to tune the shape selectivity of zeolite catalysts having pore systems of different dimensions by controlling the crystal morphology.
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Hylland, Knut Tormodssønn; Øien-Ødegaard, Sigurd; Lillerud, Karl Petter & Tilset, Mats
(2015).
Efficient, Scalable Syntheses of Linker Molecules for Metal-Organic Frameworks.
Synlett : Accounts and Rapid Communications in Synthetic Organic Chemistry.
ISSN 0936-5214.
26(11),
p. 1480–1485.
doi:
10.1055/s-0034-1381039.
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Aunan, Erlend Solbakken; Affolter, Christopher & Lillerud, Karl Petter
(2019).
Post-synthetic functionalization of MOF-808.
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Research of zirconium-based metal-organic frameworks has for the past ten years steadily increased in popularity, and new methods for synthesis, modification and functionalization are published regularly. In the leading front of the research is the UiO-series[1] (UiO-66, UiO-67 and UiO-68). The series has have shown great thermal, chemical and physical stability, which partly is due to having each cluster fully coordinated to linkers (12 linkers per cluster, 6:1 ratio). Although the full coordination sphere increases their resistant properties, it leaves little room for functionalizing, leading to a necessity of introducing either missing linker defects in order to introduce new functionality to the MOF, or even direct chemical functionalization of the linkers themselves.
MOF-808[2] is a MOF consisting of zirconium and trimesic acid (benzene-1,3,5-tricarboxcylic acid), and while having the same cluster as the UiO-series (Zr6O4(OH)4), only six linkers are coordinated per cluster (2:1 ratio), leaving another six coordination sites in an equatorial belt around the cluster uncoordinated. These six sites are often occupied by remnant anionic species from the synthesis (chloride, formate, acetate etc.), but these species can be exchanged for others in order to increase the functionalization of the MOF. In this work, an overview of the introduction of different functionalities into MOF-808 is shown.
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Øien-Ødegaard, Sigurd; Shearer, Greig Charles; Lillerud, Karl Petter & Bordiga, Silvia
(2019).
Metal-organic Framework Sponges.
In Trotta, Francesco (Eds.),
Nanosponges: Synthesis and Applications.
Wiley-VCH.
ISSN 9783527340996.
p. 59–122.
Full text in Research Archive
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Kaur, Gurpreet; Øien-Odegaard, Sigurd; Olsbye, Unni & Lillerud, Karl Petter
(2018).
Designing and developing MOFs for catalysis.
Full text in Research Archive
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Olsbye, Unni & Lillerud, Karl Petter
(2016).
Nanoporous catalysts - from zeolites and zeotypes to metal-organic frameworks.
Full text in Research Archive
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Øien-Ødegaard, Sigurd; Hylland, Knut Tormodssønn; Tilset, Mats & Lillerud, Karl Petter
(2016).
Linker Design and Synthesis for Improved Stability and Performance of Zr-MOFs.
Full text in Research Archive
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Thoresen, Eirik Mydske; Amedjkouh, Mohamed; Tilset, Mats; Lillerud, Karl Petter; Øien-Ødegaard, Sigurd & Balcells, David
(2016).
Novel Ruthenium Functionalized Linkers for Photosensitization of Metal-Organic Frameworks.
Full text in Research Archive
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Lillerud, Karl Petter; Shearer, Greig Charles; Øien-Ødegaard, Sigurd; Chavan, Sachin Maruti & Hylland, Knut Tormodssønn
(2016).
Order and Chaos in Zr-MOFs.
Full text in Research Archive
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Øien-Ødegaard, Sigurd; Braglia, Luca; Lamberti, Carlo & Lillerud, Karl Petter
(2016).
Direct Probing of Postsynthetic Modifications in Zr-MOF Single Crystals.
Full text in Research Archive
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Thoresen, Eirik Mydske; Tilset, Mats; Lillerud, Karl Petter & Amedjkouh, Mohamed
(2015).
Functionalized linkers as photosensitizers in UiO-67 MOFs
for photocatalytic CO2 reduction.
Full text in Research Archive
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Thoresen, Eirik Mydske; Tilset, Mats; Lillerud, Karl Petter & Amedjkouh, Mohamed
(2015).
Metal organic frameworks (MOFs) with functionalized linkers
as photosensitizers for photocatalytic CO2 reduction.
Full text in Research Archive
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Olsbye, Unni & Lillerud, Karl Petter
(2015).
Catalysis in confined space - from zeolites and zeotypes to functionalized metal organic frameworks.
Full text in Research Archive
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Hylland, Knut Tormodssønn; Øien-Ødegaard, Sigurd; Tilset, Mats & Lillerud, Karl Petter
(2015).
Synthesis of new linker molecules for Metal-Organic Frameworks.
Full text in Research Archive
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Hylland, Knut Tormodssønn; Øien-Ødegaard, Sigurd; Tilset, Mats & Lillerud, Karl Petter
(2015).
Synthesis of new linker molecules for Metal-Organic Frameworks.
Full text in Research Archive
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Hylland, Knut Tormodssønn; Øien-Ødegaard, Sigurd; Tilset, Mats & Lillerud, Karl Petter
(2015).
From synthesis of small organic molecules to material assembly and characterization: Synthesis of linker molecules for Metal-Organic Frameworks.
Full text in Research Archive
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Thoresen, Eirik Mydske; Tilset, Mats; Lillerud, Karl Petter & Amedjkouh, Mohamed
(2015).
Metal organic frameworks (MOFs) with functionalized linkers as photosensitizers for photocatalytic CO2 reduction.
Full text in Research Archive
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Kømurcu, Mustafa; Olsbye, Unni & Lillerud, Karl Petter
(2021).
Tailoring solid catalysts for the ethene oligomerization reaction.
Universitetet i Oslo.
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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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Kaur, Gurpreet; Lillerud, Karl Petter & Øien-Ødegaard, Sigurd
(2020).
Optimization of UiO-67 type Metal-Organic Frameworks for Catalysis.
Universitetet i Oslo.
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Materials with pores of controlled size and connectivity are of fundamental importance in chemical industry and research. The pores in microporous materials, which have the same dimensions as individual molecules, can be used for the immobilisation of active sites to develop these materials into catalysts. Zeolites and metal-organic frameworks (MOFs) are two such widely studied materials in this aspect. The main objective of my work has been to synthesize MOFs with specific catalytically active sites. As basis of the study, the Zr-biphenyl MOF UiO-67 was chosen, due to its high stability and demonstrated abilities to harbor a wide range of catalytic sites. UiO MOFs (Universitetet i Oslo) were discovered at the Department of Chemistry in 2008 and is now prominent in the MOF literature but its synthesis and fundamental properties has been poorly understood. Therefore, it is necessary to develop a deep understanding to control the properties of the materials by atomic scale manipulation. In this thesis a thorough study is done to refine, understand the synthesis and its effects for a stable, reproducible and reliable development of a desired material. Furthermore, the optimized protocols were implemented to develop UiO-67 type catalysts by anchoring different metals in the pores to serve as active sites. This work has helped to have a better understanding of MOF catalysts for important reactions such as CO2 hydrogenation and ethene oligomerization.
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Hylland, Knut Tormodssønn; Tilset, Mats & Lillerud, Karl Petter
(2020).
Synthesis and Reactivity of Zn Schiff Base Complexes Derived from 2, 2’-diaminobiphenyls.
Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo.
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Kumar, Sushant; Svelle, Stian & Lillerud, Karl Petter
(2020).
Potentiometric acid-base titration as a tool to characterize porous solid acids.
Universitetet i Oslo.
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Potentiometric acid-base titration was introduced to measure pKa values (Brønsted acidity) of protons in Zr_6-based metal-organic frameworks (MOFs), including UiO-type MOFs and MOF-808. The pKa values of three typical types of proton present in these MOFs, μ_3-OH, Zr - OH_2, and Zr – OH were evaluated. The two latter protons are assumed to mainly originate from missing linker. From structural characterization using techniques such as TGA, NMR, and EDS, it seemed to not entirely be the case, since standard UiO-66-BDC was observed to not have any defects from the linkers, and the small amount of chloride detected may originate from the pores of the material rather than being part of the structure. Also, one of the two standard UiO-67s (UiO-67-400) which was amorphous, could seemingly detect protons similar to the other crystalline UiO-67-PM MOF and literature. This weakens the hypothesis that potentiometric acid-base titration is a good method to characterize MOFs. All materials were characterized by PXRD, SEM/EDS, TGA, and N2-adsorption. Additionally, the acidic properties of the titrated samples were compared with MP-AES, EDS, and TPD for zeolites and FT-IR for MOFs. FT-IR was applied to discover the same Brønsted acids that were detected by potentiometric acid-base titration. The μ_3-OH proton could be found with both techniques, but the others could not be detected by the preliminary FT-IR measurements that were carried out. Potentiometric acid-base titration was also used to find the available acid site density for commercial zeolites, involving H-USY (FAU), H-BEA-25 (*BEA), and H – β (*BEA), and H-ZSM-5 (MFI). MP-AES and EDS revealed a higher Si/Al ratio (lower Al content) in all the zeolites compared with the value that was provided by the suppliers. This would predict that fewer amount of acid sites would be detected when using potentiometric titration and TPD, which appeared to be the case. The results indicated good agreement between potentiometric acid-base titration and TPD since the measured density acid sites (μmol/g) showed values comparable to each other. This was especially the case for zeolites with low Al content.
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Campo, Pablo Del; Olsbye, Unni; Lillerud, Karl Petter; Beato, Pablo & Svelle, Stian
(2017).
Improvement of the methanol-to-hydrocarbons catalytic performance for one-dimensional zeolites obtained by post-synthetic modifications.
Universitetet i Oslo.
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Mykland, Maria; Lillerud, Karl Petter & Mortén, Magnus
(2017).
Syntese og karakterisering av zeotype-materialer med AFI-type struktur.
Universitetet i Oslo.
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Denne oppgaven har hatt flere mål. Det første var å syntetisere AlPO-5 krystaller med varierende lengde samt undersøke effekten synteseparameterne konsentrasjon og aldring av syntese-gel kan ha på morfologi og størrelse. Dette ble videre brukt i forsøk på inkorporer kobber i strukturen til AlPO-5. Et mål for oppgaven har vært å lage AlPO-5 krystaller med kontrollert form, slik at det er mulig å kontrollere lengden på kanalene i strukturen. Kanalene i AlPO-5 er 1-dimensjonale. Disse er ofte parallelle med lengderetningen til krystallene. For å unngå diffusjonsbegrensinger bør derfor en AlPO-5 ha en morfologi som minimerer diffusjonsveien langs kanalene, eksempelvis plater. Det ble også gjort forsøk på å substituere Al3+ med Cu2+ for å gi materialet andre egenskaper. Vanninnholdet i syntese-gel har vist seg å påvirke forholdet mellom nukleering og krystallvekst. Lavt vanninnhold ga korte og brede krystaller, mens høyt vanninnhold fremmet krystallvekst og gav lange og tynne krystaller. Dette kom tydelig frem ved å gjøre synteser hvor vanninnholdet gradvis ble øket. Forskjellen i krystallform var målbar, selv når forskjellen i vanninnhold var liten. Det ble også sett på samspillet mellom vanninnholdet og aldring av syntese-gelen. Aldring av gelen er en lite undersøkt syntese-parameter. Det er her vist at aldring er en parameter som kan brukes for å oppnå forskjellige krystall-morfologier. Aldring av syntese-gelen fremmer nukleering, og effekten endres ved ulike konsentrasjoner. Ved høy konsentrasjon førte økende aldring til lengre krystaller. Når konsentrasjonen var middels lav minket krystallene i lengde ved økende aldring. Ved veldig lav konsentrasjon var aldring nødvendig for å få dannet et krystallint produkt. Diffusjonsstudier i TAP-reaktor viste at diffusjon av tre forskjellige probemolekyler ikke ble påvirket av lengden til krystallene. Det har i dette prosjektet ikke lyktes å inkorporere kobber i gitteret til AlPO-5. Men det funnet at tilstedeværelsen av kobberioner i syntese-gelen påvirket morfologien til krystallene.
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Wu, Lianpao; Tilset, Mats & Lillerud, Karl Petter
(2015).
Synthesis and characterization of UiO-67-BNDC MOF.
Universitetet i Oslo.
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In this study, the 1,1'-binaphthyl-4,4'-dicarboxylic acid (BNDC) linker has been synthesized by six-step synthesis route in five gram level. Meanwhile, a four-step synthesis route was also explored in a milligram scale. Then a new Zr-MOF with the BNDC linker was prepared by the conventional method. The synthesis of this MOF single crystal was also tested.This new Zr-MOF was characterized by a various methods including powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), N2 adsorption, CO2 and methane adsorption, optical microscope and nuclear magnetic resonance (NMR) spectroscopy, water stability test, pH stability test, and scanning electron microscope (SEM).
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Published
Nov. 11, 2010 9:00 AM
- Last modified
Oct. 25, 2021 4:52 PM
