B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Zhaodong
Zhu
,
Mengtian
Fan
,
Meng
He
,
Bing
An
,
Yinlin
Chen
,
Shaojun
Xu
,
Tianze
Zhou
,
Alena M.
Sheveleva
,
Meredydd
Kippax-Jones
,
Lutong
Shan
,
Yongqiang
Chen
,
Hamish
Cavaye
,
Jeff
Armstrong
,
Svemir
Rudic
,
Stewart F.
Parker
,
William
Thornley
,
Evan
Tillotson
,
Matthew
Lindley
,
Shenglong
Tian
,
Daniel
Lee
,
Shiyu
Fu
,
Mark D.
Frogley
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sarah J.
Haigh
,
Sihai
Yang
Abstract: The methanol-to-olefins (MTO) process has the potential to bridge future gaps in the supply of sustainable lower olefins. Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions. Here, we report a novel heteroatomic silicoaluminophosphate (SAPO) zeolite, SAPO-34-Ta, which incorporates active tantalum(V) sites within the framework to afford an optimal distribution of acidity. SAPO-34-Ta exhibits a remarkable total selectivity of 85.8% for propylene and ethylene with a high selectivity of 54.9% for propylene on full conversion of methanol at 400 oC. In situ and operando synchrotron powder X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering, coupled with theoretical calculations, reveal trimethyloxonium as the key reaction intermediate, promoting the formation of first carbon-carbon bonds in olefins. The tacit cooperation between tantalum(V) and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.
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Jan 2025
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Yu
Han
,
Wenyuan
Huang
,
Meng
He
,
Bing
An
,
Yinlin
Chen
,
Xue
Han
,
Lan
An
,
Meredydd
Kippax-Jones
,
Jiangnan
Li
,
Yuhang
Yang
,
Mark D.
Frogley
,
Cheng
Li
,
Danielle
Crawshaw
,
Pascal
Manuel
,
Svemir
Rudic
,
Yongqiang
Chen
,
Ian
Silverwood
,
Luke L.
Daemen
,
Anibal J.
Ramirez-Cuesta
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Ben F.
Spencer
,
Marek
Nikiel
,
Daniel
Lee
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[37155, 36474]
Open Access
Abstract: Capture of trace benzene is an important and challenging task. Metal–organic framework materials are promising sorbents for a variety of gases, but their limited capacity towards benzene at low concentration remains unresolved. Here we report the adsorption of trace benzene by decorating a structural defect in MIL-125-defect with single-atom metal centres to afford MIL-125-X (X = Mn, Fe, Co, Ni, Cu, Zn; MIL-125, Ti8O8(OH)4(BDC)6 where H2BDC is 1,4-benzenedicarboxylic acid). At 298 K, MIL-125-Zn exhibits a benzene uptake of 7.63 mmol g−1 at 1.2 mbar and 5.33 mmol g−1 at 0.12 mbar, and breakthrough experiments confirm the removal of trace benzene (from 5 to <0.5 ppm) from air (up to 111,000 min g−1 of metal–organic framework), even after exposure to moisture. The binding of benzene to the defect and open Zn(II) sites at low pressure has been visualized by diffraction, scattering and spectroscopy. This work highlights the importance of fine-tuning pore chemistry for designing adsorbents for the removal of air pollutants.
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Nov 2024
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B22-Multimode InfraRed imaging And Microspectroscopy
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Dukula
De Alwis Jayasinghe
,
Yinlin
Chen
,
Jiangnan
Li
,
Justyna M.
Rogacka
,
Meredydd
Kippax-Jones
,
Wanpeng
Lu
,
Sergey
Sapchenko
,
Jinyue
Yang
,
Sarayute
Chansai
,
Tianze
Zhou
,
Lixia
Guo
,
Yujie
Ma
,
Longzhang
Dong
,
Daniil
Polyukhov
,
Lutong
Shan
,
Yu
Han
,
Danielle
Crawshaw
,
Xiangdi
Zeng
,
Zhaodong
Zhu
,
Lewis
Hughes
,
Mark D.
Frogley
,
Pascal
Manuel
,
Svemir
Rudic
,
Yongqiang
Chen
,
Christopher
Hardacre
,
Martin
Schroeder
,
Sihai
Yang
Open Access
Abstract: Ammonia (NH3) production in 2023 reached 150 million tons and is associated with potential concomitant production of up to 500 million tons of CO2 each year. Efforts to produce green NH3 are compromised since it is difficult to separate using conventional condensation chillers, but in situ separation with minimal cooling is challenging. While metal–organic framework materials offer some potential, they are often unstable and decompose in the presence of caustic and corrosive NH3. Here, we address these challenges by developing a pore-expansion strategy utilizing the flexible phosphonate framework, STA-12(Ni), which shows exceptional stability and capture of NH3 at ppm levels at elevated temperatures (100–220 °C) even under humid conditions. A remarkable NH3 uptake of 4.76 mmol g–1 at 100 μbar (equivalent to 100 ppm) is observed, and in situ neutron powder diffraction, inelastic neutron scattering, and infrared microspectroscopy, coupled with modeling, reveal a pore expansion from triclinic to a rhombohedral structure on cooperative binding of NH3 to unsaturated Ni(II) sites and phosphonate groups. STA-12(Ni) can be readily engineered into pellets or monoliths without losing adsorption capacity, underscoring its practical potential.
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Nov 2024
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Yu
Han
,
David
Brooks
,
Meng
He
,
Yinlin
Chen
,
Wenyuan
Huang
,
Boya
Tang
,
Bing
An
,
Xue
Han
,
Meredydd
Kippax-Jones
,
Mark D.
Frogley
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Svemir
Rudic
,
Yongqiang
Chen
,
Luke L.
Daemen
,
Anibal J.
Ramirez-Cuesta
,
Catherine
Dejoie
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[33115, 30398]
Open Access
Abstract: The functionalization of metal–organic frameworks (MOFs) to enhance the adsorption of benzene at trace levels remains a significant challenge. Here, we report the exceptional adsorption of trace benzene in a series of zirconium-based MOFs functionalized with chloro groups. Notably, MFM-68-Cl2, constructed from an anthracene linker incorporating chloro groups, exhibits a remarkable benzene uptake of 4.62 mmol g–1 at 298 K and 0.12 mbar, superior to benchmark materials. In situ synchrotron X-ray diffraction, Fourier transform infrared microspectroscopy, and inelastic neutron scattering, coupled with density functional theory modeling, reveal the mechanism of binding of benzene in these materials. Overall, the excellent adsorption performance is promoted by an unprecedented cooperation between chloro-groups, the optimized pore size, aromatic functionality, and the flexibility of the linkers in response to benzene uptake in MFM-68-Cl2. This study represents the first example of enhanced adsorption of trace benzene promoted by −CH···Cl and Cl···π interactions in porous materials.
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Oct 2024
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B22-Multimode InfraRed imaging And Microspectroscopy
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Xiangbing
Zeng
,
Jiangnan
Li
,
Meng
He
,
Wanpeng
Lu
,
Danielle
Crawshaw
,
Lixia
Guo
,
Yujie
Ma
,
Meredydd
Kippax-Jones
,
Yongqiang
Cheng
,
Pascal
Manuel
,
Svemir
Rudic
,
Mark D.
Frogley
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[30398]
Open Access
Abstract: We report the high adsorption of NH3 in the titanium-based metal-organic framework, MFM-300(Ti), comprising extended [TiO6]∞ chains linked by biphenyl-3,3’,5,5’-tetracarboxylate ligands. At 273 K and 1 bar, MFM-300(Ti) shows an exceptional NH3 uptake of 23.4 mmol g–1 with a record-high packing density of 0.84 g cm–3. Dynamic breakthrough experiments confirm the excellent uptake and separation of NH3 at low concentration (1000 ppm). The combination of in situ neutron powder diffraction and spectroscopic studies reveal strong, yet reversible binding interactions of NH3 to the framework oxygen sites.
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Apr 2024
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I12-JEEP: Joint Engineering, Environmental and Processing
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Open Access
Abstract: Despite being one of the most thoroughly characterised molecular crystals, hexamethylenetetramine (HMT) and its deuterated counterpart (DHMT), are still not fully understood, especially regarding anharmonic and nuclear quantum effects. In this work, an unprecedented combination of experimental techniques, including neutron and X-ray diffraction, inelastic neutron scattering, neutron transmission, and Compton scattering, all augmented ab initio by harmonic lattice dynamics calculations, was applied. The main question that motivated the presented work was the interplay between the phonon anharmonicity and isotope and nuclear quantum effects related to the zero-point energies of proton and deuteron. Signatures of the combined effects of isotopic substitution, temperature, anharmonicity and nuclear quantum effects were found in data from all experimental methods. In the case of neutron and X-ray diffraction, these signatures manifested as systematic discrepancies between the structural and atomic displacement parameters and thermal diffuse scattering obtained from harmonic lattice calculations and their experimental counterparts. To this end, an important effect was found that could not have been explained by the harmonic lattice modelling; the reverse Ubbelohde effect, i.e. the observation that deuteration decreases hydrogen bond length in HMT. In the case of neutron transmission, further discrepancies between theoretical predictions and experimental data were found at cryogenic temperatures. Finally, applying the diabatic theory of the local potential of the intermolecular hydrogen bond in HMT, it was possible to elucidate the degree of anharmonicity of the C–H···N bonds by relating it to the magnitude of the vibrational isotope effect for the C–H bond stretching observed in inelastic and neutron Compton scattering experiments. It was found that the combined nuclear quantum and anharmonic effects of the protons (deuterons) in hydrogen bonds in HMT (DHMT) manifest as systematic discrepancies between the ab initio predictions for the widths of nuclear momentum distributions and the experimental values.
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Jan 2023
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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[14902, 25407]
Open Access
Abstract: Owing to their unique functionalities and tailorable properties that are unattainable in conventional materials, metal-organic frameworks (MOFs) have emerged as candidate materials for next-generation chemical sensors and optoelectronics. For instance, the ZnQ@OX-1 composite material, comprising a light-emitting guest encapsulated in the pores of the OX-1 framework, affords excellent sensing performance: a visible color change upon exposure to volatile acetone. In this work, a multimodal study on the exceptional vapochromism of this composite material using high-resolution spectroscopy techniques based on inelastic neutron scattering and synchrotron radiation is presented, supported by density functional theory calculations. While FTIR spectroscopy in the far-IR and mid-IR regions reveals the underlying interactions between ZnQ, OX-1, and acetone, the limit of detection at 50 ppm is determined through in situ gas dosing experiments using fluorescence spectroscopy. In addition, in situ gas dosing on the single crystal level is achieved with near-field infrared nanospectroscopy.
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Dec 2022
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Open Access
Abstract: The purification of light olefins is one of the most important chemical separations globally and consumes large amounts of energy. Porous materials have the capability to improve the efficiency of this process by acting as solid, regenerable adsorbents. However, to develop translational systems, the underlying mechanisms of adsorption in porous materials must be fully understood. Herein, we report the adsorption and dynamic separation of C2 and C3 hydrocarbons in the metal–organic framework MFM-300(In), which exhibits excellent performance in the separation of mixtures of ethane/ethylene and propyne/propylene. Unusually selective adsorption of ethane over ethylene at low pressure is observed, resulting in selective retention of ethane from a mixture of ethylene/ethane, thus demonstrating its potential for a one-step purification of ethylene (purity > 99.9%). In situ neutron powder diffraction and inelastic neutron scattering reveal the preferred adsorption domains and host–guest binding dynamics of adsorption of C2 and C3 hydrocarbons in MFM-300(In).
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Jun 2022
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B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
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Yujie
Ma
,
Wanpeng
Lu
,
Xue
Han
,
Yinlin
Chen
,
Ivan
Da Silva
,
Daniel
Lee
,
Alena M.
Sheveleva
,
Zi
Wang
,
Jiangnan
Li
,
Weiyao
Li
,
Mengtian
Fan
,
Shaojun
Xu
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Yongqiang
Cheng
,
Svemir
Rudic
,
Pascal
Manuel
,
Mark D.
Frogley
,
Anibal J.
Ramirez-Cuesta
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[19850]
Open Access
Abstract: The presence of active sites in metal–organic framework (MOF) materials can control and affect their performance significantly in adsorption and catalysis. However, revealing the interactions between the substrate and active sites in MOFs at atomic precision remains a challenging task. Here, we report the direct observation of binding of NH3 in a series of UiO-66 materials containing atomically dispersed defects and open Cu(I) and Cu(II) sites. While all MOFs in this series exhibit similar surface areas (1111–1135 m2 g–1), decoration of the −OH site in UiO-66-defect with Cu(II) results in a 43% enhancement of the isothermal uptake of NH3 at 273 K and 1.0 bar from 11.8 in UiO-66-defect to 16.9 mmol g–1 in UiO-66-CuII. A 100% enhancement of dynamic adsorption of NH3 at a concentration level of 630 ppm from 2.07 mmol g–1 in UiO-66-defect to 4.15 mmol g–1 in UiO-66-CuII at 298 K is observed. In situ neutron powder diffraction, inelastic neutron scattering, and electron paramagnetic resonance, solid-state nuclear magnetic resonance, and infrared spectroscopies, coupled with modeling reveal that the enhanced NH3 uptake in UiO-66-CuII originates from a {Cu(II)···NH3} interaction, with a reversible change in geometry at Cu(II) from near-linear to trigonal coordination. This work represents the first example of structural elucidation of NH3 binding in MOFs containing open metal sites and will inform the design of new efficient MOF sorbents by targeted control of active sites for NH3 capture and storage.
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May 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
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Lixia
Guo
,
Xue
Han
,
Yujie
Ma
,
Jiangnan
Li
,
Wanpeng
Lu
,
Weiyao
Li
,
Daniel
Lee
,
Ivan
Da Silva
,
Yongqiang
Cheng
,
Svemir
Rudic
,
Pascal
Manuel
,
Mark D.
Frogley
,
Anibal Javier
Ramirez-Cuesta
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[30398]
Open Access
Abstract: To understand the exceptional adsorption of ammonia (NH3) in MFM-300(Sc) (19.5 mmol g−1 at 273 K and 1 bar without hysteresis), we report a systematic investigation of the mechanism of adsorption by a combination of in situ neutron powder diffraction, inelastic neutron scattering, synchrotron infrared microspectroscopy, and solid-state 45Sc NMR spectroscopy. These complementary techniques reveal the formation of reversible host-guest supramolecular interactions, which explains directly the observed excellent reversibility of this material over 90 adsorption-desorption cycles.
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Apr 2022
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