I15-1-X-ray Pair Distribution Function (XPDF)
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Emily V.
Shaw
,
Javier
Pérez-Carvajal
,
Elena
López-Elvira
,
Shaoliang
Guan
,
Timothy
Lambden
,
Georgina P.
Robertson
,
Arad
Lang
,
Joonatan E. M.
Laulainen
,
Celia
Chen
,
Chumei
Ye
,
Anna
Herlihy
,
Catherine
Dejoie
,
David A.
Keen
,
Paul
Midgley
,
Thomas D.
Bennett
,
Celia
Castillo-Blas
Diamond Proposal Number(s):
[31401, 39316]
Open Access
Abstract: We report a scalable, water-based methodology for the direct room-temperature synthesis of porous amorphous UiO-66-type metal–organic frameworks (aMOFs), enabling the incorporation of a range of functionalised terepthalate linkers without organic solvents during framework formation. Powder X-ray diffraction and scanning electron diffraction confirm the formation of truly topologically amorphous UiO-66 derivatives, while pair distribution function (PDF) analysis shows that the amorphous frameworks retain the local structural motifs of their crystalline analogues despite the loss of long-range order. Relative to crystalline UiO-66, the directly synthesised amorphous UiO-66 exhibits a reduced but permanent porosity (BET surface area 286 vs. 997 m2 g−1 CO2-accessible pore volume 0.196 vs. 0.519 cm3 g−1), together with a high concentration of defects, consistent with a cluster[thin space (1/6-em)]:[thin space (1/6-em)]linker ratio of 1[thin space (1/6-em)]:[thin space (1/6-em)]5.3 compared with 1[thin space (1/6-em)]:[thin space (1/6-em)]6 for the ideal crystalline framework. In the esterification of levulinic acid, amorphous UiO-66 reaches 87.7% conversion to methyl levulinate after 3 h, compared with 75.5% for crystalline UiO-66, and retains 95% of its initial activity after five catalytic cycles (vs. 86% for the crystalline analogue). These results demonstrate that direct, water-based synthesis provides access to functional, porous, and highly defective amorphous UiO-66 materials with catalytic performance comparable to or exceeding that of their crystalline counterparts under the conditions studied.
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Mar 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
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Georgina P.
Robertson
,
Emily V.
Shaw
,
Florencia A.
Son
,
Celia
Castillo-Blas
,
Bethan
Turner
,
James M. A.
Steele
,
Christopher A.
O'Keefe
,
Kirill A.
Lomachenko
,
Angelika D.
Rosa
,
Daniel J. M.
Irving
,
Michael F.
Thorne
,
Alice M.
Bumstead
,
Omar K.
Farha
,
Lauren N.
Mchugh
,
David A.
Keen
,
Philip A.
Chater
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038, 29957]
Abstract: Defect engineering of metal–organic frameworks (MOFs) has been shown to impact many properties of these porous structures, including affecting the accessible pore volume as well as introducing additional active sites to modify the catalytic activity of the frameworks. However, this defect engineering has previously primarily been carried out through synthesis-based methods. Ball-milling of the frameworks presents an alternative method for the introduction of defects, which has not been largely investigated for its effects on catalysis. The complex pressure states experienced during milling result in property changes, both enhancing and diminishing defect accessibility, necessitating a detailed investigation. This work characterizes three Zirconium-based MOFs (UiO-66, MOF-808, and NU-1000), using total scattering X-ray diffraction, infrared spectroscopy, and thermal analysis to investigate their collapse and defect introduction during all stages of ball-milling. It then assesses the utility of ball-milling UiO-66 to different extents as a method for improving catalytic abilities within two reactions, the formation of propargylamine, and the conversion of glucose to fructose. The mechanical amorphization of UiO-66 led to either an increase or a decrease in catalytic ability depending on the milling time and the reaction investigated.
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Feb 2026
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I15-1-X-ray Pair Distribution Function (XPDF)
I20-EDE-Energy Dispersive EXAFS (EDE)
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Diamond Proposal Number(s):
[30676, 30178]
Abstract: Zeolitic imidazolate frameworks (ZIFs), a subclass of metal–organic frameworks (MOFs), combine high porosity and chemical tunability with a resistance to harsh conditions. Understanding their response to extreme pressure and heat is critical for application development due to the conditions under which they may be required to work or for predicting their response to any processing before use. In this study, we characterize long- and short-range order in ZIF-8 and ZIF-62 under compression using Bragg X-ray diffraction and pair distribution function (PDF) analysis for a large pressure range (up to ∼5 GPa) previously attempted in very few works. X-ray absorption fine structure analysis was carried out under high-pressure-temperature conditions to probe the medium-range order, a novelty in MOFs. ZIF-8 demonstrated a crystalline–crystalline phase transition above 0.36 GPa but no full amorphization. In ZIF-62, pore intrusion of the silicone oil pressure-transmitting medium (PTM) was observed through negative compressibility and by retention of its open-pore configuration. Full amorphization was achieved, with heating lowering the amorphization threshold. Finally, a unique distortion in both MOFs was suggested by the spectroscopic data. These results provide insight into the thermomechanical stability of crystalline ZIFs and the mechanism underlying their amorphization.
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Dec 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Chumei
Ye
,
Lauren N.
Mchugh
,
Pierre
Florian
,
Ruohan
Yu
,
Celia
Castillo-Blas
,
Celia
Chen
,
Arad
Lang
,
Yuhang
Dai
,
Jingwei
Hou
,
David A.
Keen
,
Sian E.
Dutton
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[35405]
Open Access
Abstract: Hybrid organic-inorganic perovskites (HOIPs) have garnered significant attention for their crystalline properties, yet recent findings reveal that they can also form liquid and glassy phases, offering an alternative platform for understanding non-crystalline materials. In this study, we present a detailed investigation into the structural dynamics of the melting and glass formation process of a two-dimensional (2D) HOIP, (S−(−)−1-(1−naphthyl)ethylammonium)2PbBr4. Compared to its crystalline counterpart, the glass exhibits superior mechanical properties, including higher Young’s modulus and hardness. Our structural studies reveal that the liquid and glass formed from the 2D HOIP exhibit network-forming behaviour, featuring limited short-range order within individual octahedra, partial retention of metal-halide-metal connectivity between neighbouring octahedra, and residual structural correlations mediated by organic cations. We then combine in situ variable-temperature X-ray total scattering experiments, terahertz far-infrared absorption spectroscopy and solid-state nuclear magnetic resonance techniques to study the melting mechanism and the nature of the HOIP liquid obtained. Our results deepen the understanding of the structural evolution and property relationships in HOIP glasses, providing a foundation for their potential applications in advanced phase-change material technologies.
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Aug 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[34797]
Open Access
Abstract: MOF@COF composites have emerged as a promising class of engineered materials with unique functionalities, combining the high porosity and tunability of metal-organic frameworks (MOFs) with the chemical and mechanical stability of covalent-organic frameworks (COFs). While their advantageous properties are well-recognized, their structural intricacies and the nature of the interfacial interactions remain insufficiently explored. In this study, a Fe-MOF@COF composite is presented, exhibiting dual functionalities for the efficient removal of organic pollutants from water. The enhanced performance is attributed to the unique properties of the MOF-COF interface, where synergistic interactions between the two porous materials play a critical role. Advanced synchrotron techniques were employed to probe interfacial interactions at the atomic and molecular levels. These findings underscore the potential of Fe-MOF@COF composite as a highly effective material for water remediation, providing deeper insights into their structural behavior and interfacial properties.
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Aug 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[29957]
Open Access
Abstract: The development of metal-organic framework (MOF) crystal-glass composites (CGCs) has been hindered by the scarcity of MOF glass matrices with low glass transition temperatures (Tgs). Here, we investigate a CGC consisting of a low-Tg MOF glass, (agZIF-UC-7) and UiO-66. Powder X-ray diffraction and stability tests in phosphate buffer saline solution showed UiO-66 was stabilised in the glass matrix. Additionally, the composite exhibited enhanced dye uptake and gas adsorption relative to agZIF-UC-7.
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Jul 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Celia
Castillo-Blas
,
Montaña J.
García
,
Ashleigh M.
Chester
,
Matjaž
Mazaj
,
Shaoliang
Guan
,
Georgina P.
Robertson
,
Ayano
Kono
,
James M. A.
Steele
,
Luis
León-Alcaide
,
Bruno
Poletto-Rodrigues
,
Philip A.
Chater
,
Silvia
Cabrera
,
Andraž
Krajnc
,
Lothar
Wondraczek
,
David A.
Keen
,
Jose
Alemán
,
Thomas
Bennett
Diamond Proposal Number(s):
[29957]
Open Access
Abstract: Metal–organic framework (MOF) composites are proposed as solutions to the mechanical instability of pure MOF materials. Here, we present a new compositional series of recently discovered MOF–crystalline inorganic glass composites. In this case, formed by the combination of a photocatalytic titanium MOF (MIL-125-NH2) and a phosphate-based glass (20%Na2O–10%Na2SO4–70%P2O5). This new family of composites has been synthesized and characterized using powder X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X-ray total scattering. Through analysis of the pair distribution function extracted from X-ray total scattering data, the atom–atom interactions at the MOF–glass interface are described. Nitrogen and carbon dioxide isotherms demonstrate good surface area values despite the pelletization and mixing of the MOF with a dense inorganic glass. The catalytic activity of these materials was investigated in the photooxidation of amines to imines, showing the retention of the photocatalytic effectiveness of the parent pristine MOF.
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Mar 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[29957]
Open Access
Abstract: We report the solvent-free synthesis of a crystalline heterometallic imidazolate derivative with formula [Fe1Zn2(im)6(Him)2], designated MUV-25, incorporating both iron and zinc. The structure imposes strict positional constraints on the metal centres due to the lattice containing distinct geometric coordination sites, tetrahedral and octahedral. As a consequence, each metal is exclusively directed to its specific coordination site, ensuring precise spatial organization within the lattice. Atom locations were meticulously monitored utilizing X-ray diffraction (single crystal and total scattering) and XAS techniques, demonstrating that the tetrahedral sites are occupied exclusively by zinc, and the octahedral sites are occupied by iron. This combination of metal centres results, upon heating, in a structural phase transformation to the zni topology at a very low temperature. Further heating causes the melting of the solid, yielding a heterometallic MOF-derived glass. The methodology lays the groundwork for tailoring crystalline structures to advance the development of novel materials capable of melting and forming glasses upon cooling.
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Mar 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Shichun
Li
,
Chao
Ma
,
Jingwei
Hou
,
Shuwen
Yu
,
Aibing
Chen
,
Juan
Du
,
Philip A.
Chater
,
Dean S.
Keeble
,
Zhihua
Qiao
,
Chongli
Zhong
,
David A.
Keen
,
Yu
Liu
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038]
Open Access
Abstract: Crystalline metal-organic frameworks (MOFs) exhibit enormous potential application in gas separation, thanks to their highly porous structures and precise pore size distributions. Nevertheless, the inherent limitations in mechanical stability of crystalline MOFs cause challenges in processing MOF powders into bulky structures, particularly for membrane filtrations. Melt-quenched MOF glasses boast excellent processability due to liquid-like properties. However, the melting process diminishes the inherent porosity, leading to reduced gas adsorption capacities and lower gas diffusion coefficients. In this work, we demonstrated that enhancing the porosity of MOF glasses is achievable through topological engineering on the crystalline precursors. Crystalline zeolitic imidazolate frameworks (ZIFs) with large 12-membered rings pores, including AFI and CAN topology, were synthesized by using both structure-directing agents and mixed organic ligands. The large pores are partially preserved in the melt-quenched glass as evidenced by high-pressure CO2 absorption at 3000 kPa. The agAFI-[Zn(Im)1.68(bIm)0.32] glass was then fabricated into self-supported membranes, which shows high gas separation performance, for example, CO2 permeance of 3.7 × 104 GPU with a CO2/N2 selectivity of 14.8.
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Feb 2025
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Emily V.
Shaw
,
Celia
Castillo Blas
,
Timothy
Lambden
,
Beatriz
De Santos
,
Bethan
Turner
,
Giulio I.
Lampronti
,
Joonatan E. M.
Laulainen
,
Georgina
Robertson
,
Ashleigh M.
Chester
,
Chumei
Ye
,
Shaoliang
Guan
,
Joshua
Karlsson
,
Valentina
Martinez
,
Ivana
Brekalo
,
Bahar
Karadeniz
,
Silvia
Cabrera
,
Lauren N.
Mchugh
,
Krunoslav
Užarević
,
Jose
Aleman
,
Alberto
Fraile
,
Rachel C
Evans
,
Paul
Midgley
,
David A.
Keen
,
Xavier
Moya
,
Thomas D.
Bennett
Open Access
Abstract: In this work, we investigated the response of the metal-organic framework MIL-125-NH2 to ball-milling. Both localised and bulk analyses revealed that prolongued ball-milling results in a complete loss of long-range structural order. Investigation of this disorder revealed partial retention of the local bonding of the secondary building unit, suggesting structure collapse progressed primarily through metal-linker bond breakage. We explored the photocatalytic performance of the materials, and examined the materials’ band gap using UV-Vis reflectance spectroscopy.
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Feb 2025
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