B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Yu
Han
,
Yinlin
Chen
,
Yujie
Ma
,
Jamie
Bailey
,
Zi
Wang
,
Daniel
Lee
,
Alena M.
Sheveleva
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Mark D.
Frogley
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Ben F.
Spencer
,
Marek
Nikiel
,
Pascal
Manuel
,
Danielle
Crawshaw
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[30398]
Open Access
Abstract: Benzene is an important air pollutant and a key chemical feedstock for the synthesis of cyclohexane. Because of the small difference of 0.6°C in their boiling points, the separation of benzene and cyclohexane is extremely challenging. Here, we report the high adsorption of benzene at low pressure and efficient separation of benzene/cyclohexane, achieved by the control of pore chemistry of two families of robust metal-organic frameworks, UiO-66 and MFM-300. At 298 K, UiO-66-CuII shows an exceptional adsorption of benzene of 3.92 mmol g−1 at 1.2 mbar and MFM-300(Sc) exhibits a high selectivity of 166 for the separation of benzene/cyclohexane (v/v = 1/1) mixture. In situ synchrotron X-ray diffraction and neutron powder diffraction, and multiple spectroscopic techniques reveal the binding mechanisms of benzene and cyclohexane in these materials. We also report the first example of direct visualization of reversible binding of benzene at an open Cu(II) site within metal-organic frameworks.
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Feb 2023
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I11-High Resolution Powder Diffraction
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Robert D.
Smyth
,
Jack N.
Blandy
,
Ziyu
Yu
,
Shuai
Liu
,
Craig V.
Topping
,
Simon J.
Cassidy
,
Catherine F.
Smura
,
Daniel N.
Woodruff
,
Pascal
Manuel
,
Craig L.
Bull
,
Nicholas P.
Funnell
,
Christopher J.
Ridley
,
John E.
Mcgrady
,
Simon J.
Clarke
Diamond Proposal Number(s):
[13284, 18786, 25166]
Open Access
Abstract: Sr2NiO2Cu2Se2, comprising alternating [Sr2NiO2]2+ and [Cu2Se2]2– layers, is reported. Powder neutron diffraction shows that the Ni2+ ions, which are in a highly elongated NiO4Se2 environment with D4h symmetry, adopt a high-spin configuration and carry localized magnetic moments which order antiferromagnetically below ∼160 K in a √2a × √2a × 2c expansion of the nuclear cell with an ordered moment of 1.31(2) μB per Ni2+ ion. The adoption of the high-spin configuration for this d8 cation in a pseudo-square-planar ligand field is supported by consideration of the experimental bond lengths and the results of density functional theory (DFT) calculations. This is in contrast to the sulfide analogue Sr2NiO2Cu2S2, which, according to both experiment and DFT calculations, has a much more elongated ligand field, more consistent with the low-spin configuration commonly found for square-planar Ni2+, and accordingly, there is no evidence for magnetic moment on the Ni2+ ions. Examination of the solid solution Sr2NiO2Cu2(Se1–xSx)2 shows direct evidence from the evolution of the crystal structure and the magnetic ordering for the transition from high-spin selenide-rich compounds to low-spin sulfide-rich compounds as a function of composition. Compression of Sr2NiO2Cu2Se2 up to 7.2 GPa does not show any structural signature of a change in the spin state. Consideration of the experimental and computed Ni2+ coordination environments and their subtle changes as a function of temperature, in addition to transitions evident in the transport properties and magnetic susceptibilities in the end members, Sr2NiO2Cu2Se2 and Sr2NiO2Cu2S2, suggest that simple high-spin and low-spin models for Ni2+ may not be entirely appropriate and point to further complexities in these compounds.
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Oct 2022
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[18786, 25166]
Open Access
Abstract: Two novel chromium oxide arsenide materials have been synthesized, Sr2CrO2Cr2OAs2 (i.e., Sr2Cr3As2O3) and Sr2CrO3CrAs (i.e., Sr2Cr2AsO3), both of which contain chromium ions in two distinct layers. Sr2CrO2Cr2OAs2 was targeted following electron microscopy measurements on a related phase. It crystallizes in the space group P4/mmm and accommodates distorted CrO4As2 octahedra containing Cr2+ and distorted CrO2As4 octahedra containing Cr3+. In contrast, Sr2CrO3CrAs incorporates Cr3+ in CrO5 square-pyramidal coordination in [Sr2CrO3]+ layers and Cr2+ ions in CrAs4 tetrahedra in [CrAs]− layers and crystallizes in the space group P4/nmm. Powder neutron diffraction data reveal antiferromagnetic ordering in both compounds. In Sr2CrO3CrAs the Cr2+ moments in the [CrAs]− layers exhibit long-range ordering, while the Cr3+ moments in the [Sr2CrO3]+ layers only exhibit short-range ordering. However, in Sr2CrO2Cr2OAs2, both the Cr2+ moments in the CrO4As2 environments and the Cr3+ moments in the CrO2As4 polyhedra are long-range-ordered below 530(10) K. Above this temperature, only the Cr3+ moments are ordered with a Néel temperature slightly in excess of 600 K. A subtle structural change is evident in Sr2CrO2Cr2OAs2 below the magnetic ordering transitions.
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Jul 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Jin
Chen
,
Qingqing
Mei
,
Yinlin
Chen
,
Christopher
Marsh
,
Bing
An
,
Xue
Han
,
Ian P.
Silverwood
,
Ming
Li
,
Yongqiang
Cheng
,
Meng
He
,
Xi
Chen
,
Weiyao
Li
,
Meredydd
Kippax-Jones
,
Danielle
Crawshaw
,
Mark D.
Frogley
,
Sarah J.
Day
,
Victoria
García-Sakai
,
Pascal
Manuel
,
Anibal J.
Ramirez-Cuesta
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[29649]
Open Access
Abstract: The development of materials showing rapid proton conduction with a low activation energy and stable performance over a wide temperature range is an important and challenging line of research. Here, we report confinement of sulfuric acid within porous MFM-300(Cr) to give MFM-300(Cr)·SO4(H3O)2, which exhibits a record-low activation energy of 0.04 eV, resulting in stable proton conductivity between 25 and 80 °C of >10–2 S cm–1. In situ synchrotron X-ray powder diffraction (SXPD), neutron powder diffraction (NPD), quasielastic neutron scattering (QENS), and molecular dynamics (MD) simulation reveal the pathways of proton transport and the molecular mechanism of proton diffusion within the pores. Confined sulfuric acid species together with adsorbed water molecules play a critical role in promoting the proton transfer through this robust network to afford a material in which proton conductivity is almost temperature-independent.
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Jul 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
I19-Small Molecule Single Crystal Diffraction
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Weiyao
Li
,
Jiangnan
Li
,
Thien D.
Duong
,
Sergey A.
Sapchenko
,
Xue
Han
,
Jack D.
Humby
,
George F. S.
Whitehead
,
Inigo J.
Vitórica-Yrezábal
,
Ivan
Da Silva
,
Pascal
Manuel
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[28479, 23480]
Open Access
Abstract: The development of efficient sorbent materials for sulfur dioxide (SO2) is of key industrial interest. However, due to the corrosive nature of SO2, conventional porous materials often exhibit poor reversibility and limited uptake toward SO2 sorption. Here, we report high adsorption of SO2 in a series of Cu(II)-carboxylate-based metal–organic framework materials. We describe the impact of ligand functionalization and open metal sites on the uptake and reversibility of SO2 adsorption. Specifically, MFM-101 and MFM-190(F) show fully reversible SO2 adsorption with remarkable capacities of 18.7 and 18.3 mmol g–1, respectively, at 298 K and 1 bar; the former represents the highest reversible uptake of SO2 under ambient conditions among all porous solids reported to date. In situ neutron powder diffraction and synchrotron infrared microspectroscopy enable the direct visualization of binding domains of adsorbed SO2 molecules as well as host–guest binding dynamics. We have found that the combination of open Cu(II) sites and ligand functionalization, together with the size and geometry of metal–ligand cages, plays an integral role in the enhancement of SO2 binding.
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Jul 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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I11-High Resolution Powder Diffraction
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Shanshan
Liu
,
Yinlin
Chen
,
Bin
Yue
,
Chang
Wang
,
Bin
Qin
,
Yuchao
Chai
,
Guangjun
Wu
,
Jiangnan
Li
,
Xue
Han
,
Ivan
Da Silva
,
Pascal
Manuel
,
Sarah J.
Day
,
Naijia
Guan
,
Stephen P.
Thompson
,
Sihai
Yang
,
Landong
Li
Diamond Proposal Number(s):
[29649]
Abstract: The development of cost-effective sorbents for direct capture of trace CO 2 (<1%) from the atmosphere is an important and challenging task. Natural or commercial zeolites are promising sorbents, but their performance in adsorption of trace CO 2 has been poorly explored to date. Herein, we report a systematic study on capture of trace CO 2 by commercial faujasite zeolites, where we found that the extra-framework cations played a key role on their performance. Under dry conditions, Ba-X displays high dynamic uptake of 1.79 and 0.69 mmol g -1 at CO 2 concentrations of 10000 and 1000 ppm, respectively, and shows excellent recyclability in the temperature-swing adsorption processes. K-X exhibits perfect moisture resistance, and >95 % dry CO 2 uptake can be preserved under relative humidity of 74%. In situ solid-state NMR spectroscopy, synchrotron X-ray diffraction and neutron diffraction reveal two binding sites for CO 2 in these zeolites, namely the basic framework oxygen atoms and the divalent alkaline earth metal ions. This study unlocks the potential of low-cost natural zeolites for applications in direct air capture.
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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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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[18786, 25166]
Abstract: The layered oxide chalcogenides Ba3-xSrxFe2O5Cu2Ch2 (x = 0, 1, 2; Ch = S, Se) and BaCa2Fe2O5Cu2S2 are reported here for the first time. They are isostructural with the previously reported Sr3Fe2O5Cu2Ch2, crystallising in the I4/mmm space group. This structure is related to the n = 2 Ruddlesden-Popper type structure which is common for oxides and contains Sr3Fe2O5 perovskite-related slabs intergrown with Cu2Ch2 layers which resemble fragments of the antifluorite structure. In the oxide slabs, a double layer of FeO5 pyramids is formed by the sharing of apical oxide ions. Structural analysis shows a clear partial ordering of the alkaline earth cations of different sizes over the available 12 and 8-coordinate sites which correlates with the size variation of the alkaline earth cations. Long range magnetic ordering on a √2a × √2a × c expansion of the nuclear cell reveals nearest neighbour Fe3+ moments coupling antiferromagnetically via all the Fe–O–Fe linkages. In Ba3Fe2O5Cu2Se2, the moments are oriented in the ab-plane, whereas in Ba3-xSrxFe2O5Cu2Ch2 (x = 2; Ch = S, Se), the Fe3+ moments are tilted towards the c-axis, reflecting that high spin d5 ions with no orbital angular momentum have only a weak preference for a particular spin direction.
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Dec 2021
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