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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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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Lydia
Briggs
,
Ruth
Newby
,
Xue
Han
,
Christopher
Morris
,
Mathew
Savage
,
Cristina
Perez
,
Timothy L.
Easun
,
Mark
Frogley
,
Gianfelice
Cinque
,
Claire A.
Murray
,
Chiu C.
Tang
,
Sihai
Yang
,
Junliang
Sun
,
Martin
Schroeder
Diamond Proposal Number(s):
[22137, 22138]
Open Access
Abstract: We report the adsorption of C2H2, CO2 and SO2 in a new, ultra-stable Cr(III)-based MOF, MFM-300(Cr), {[Cr2(OH)2(L)], H4L = biphenyl-3,3',5,5'-tetracarboxylic acid}. MFM-300(Cr) shows uptakes of 7.37, 7.73 and 8.59 mmol g-1 for CO2, C2H2 and SO2, respectively, at 273 K, 1.0 bar, and shows a higher selectivity for SO2/CO2 compared with the Al(III) analogue MFM-300(Al) (selectivity of 79 vs. 45). In order to monitor the effects of changing metal centre on gas uptake and to integrate the properties of the homometallic analogues, the mixed metal MFM-300(Al0.67Cr0.33), [Al1.34Cr0.66(OH)2L] has been synthesised. In situ synchrotron micro-FTIR spectroscopy has identified distinct CO2 binding environments on Al-O(H)-Al, Cr-O(H)-Cr and Al-O(H)-Cr bridges in MFM-300(Al0.67Cr0.33), and we have determined the binding domains for these gases by in situ synchrotron X-ray diffraction in both MFM-300(Cr) and MFM-300(Al0.67Cr0.33). The capability of these materials for gas separation has been confirmed by dynamic breakthrough experiments. The incorporation of Al(III) and Cr(III) within the same framework allows tuning of the host-guest and guest-guest interactions within these functional porous materials.
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Feb 2021
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I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
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Stephen P.
Argent
,
Ivan
Da Silva
,
Alex
Greenaway
,
Mathew
Savage
,
Jack
Humby
,
Andrew J.
Davies
,
Harriott
Nowell
,
William
Lewis
,
Pascal
Manuel
,
Chiu C.
Tang
,
Alexander J.
Blake
,
Michael W.
George
,
Alexander V.
Markevich
,
Elena
Besley
,
Sihai
Yang
,
Neil R.
Champness
,
Martin
Schroeder
Diamond Proposal Number(s):
[861, 11622, 15833, 9443]
Open Access
Abstract: Designing porous materials which can selectively adsorb CO2 or CH4 is an important environmental and industrial goal which requires an understanding of the host–guest interactions involved at the atomic scale. Metal–organic polyhedra (MOPs) showing permanent porosity upon desolvation are rarely observed. We report a family of MOPs (Cu-1a, Cu-1b, Cu-2), which derive their permanent porosity from cavities between packed cages rather than from within the polyhedra. Thus, for Cu-1a, the void fraction outside the cages totals 56% with only 2% within. The relative stabilities of these MOP structures are rationalized by considering their weak nondirectional packing interactions using Hirshfeld surface analyses. The exceptional stability of Cu-1a enables a detailed structural investigation into the adsorption of CO2 and CH4 using in situ X-ray and neutron diffraction, coupled with DFT calculations. The primary binding sites for adsorbed CO2 and CH4 in Cu-1a are found to be the open metal sites and pockets defined by the faces of phenyl rings. More importantly, the structural analysis of a hydrated sample of Cu-1a reveals a strong hydrogen bond between the adsorbed CO2 molecule and the Cu(II)-bound water molecule, shedding light on previous empirical and theoretical observations that partial hydration of metal−organic framework (MOF) materials containing open metal sites increases their uptake of CO2. The results of the crystallographic study on MOP–gas binding have been rationalized using DFT calculations, yielding individual binding energies for the various pore environments of Cu-1a.
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Oct 2020
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
I12-JEEP: Joint Engineering, Environmental and Processing
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Harry G. W.
Godfrey
,
Lydia
Briggs
,
Xue
Han
,
William J. F.
Trenholme
,
Christopher
Morris
,
Mathew
Savage
,
Louis
Kimberley
,
Oxana
Magdysyuk
,
Michael
Drakopoulos
,
Claire A.
Murray
,
Chiu C.
Tang
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[11278]
Open Access
Abstract: Understanding the mechanism of assembly and function of metal-organic frameworks (MOFs) is important for the development of practical materials. Herein, we report a time-resolved diffraction analysis of the kinetics of formation of a robust MOF, MFM-300(Fe), which shows high adsorption capacity for CO2 (9.55 mmol g−1 at 293 K and 20 bar). Applying the Avrami-Erofe’ev and the two-step kinetic Finke-Watzky models to in situ high-energy synchrotron X-ray powder diffraction data obtained during the synthesis of MFM-300(Fe) enables determination of the overall activation energy of formation (50.9 kJ mol−1), the average energy of nucleation (56.7 kJ mol−1), and the average energy of autocatalytic growth (50.7 kJ mol−1). The synthesis of MFM-300(Fe) has been scaled up 1000-fold, enabling the successful breakthrough separations of the CO2/N2 mixture in a packed-bed with a selectivity for CO2/N2 of 21.6. This study gives an overall understanding for the intrinsic behaviors of this MOF system, and we have determined directly the binding domains and dynamics for adsorbed CO2 molecules within the pores of MFM-300(Fe).
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Nov 2019
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Martin
Schroder
,
Harry
Godfrey
,
Ivan
Da Silva
,
Lydia
Briggs
,
Joe
Carter
,
Christopher
Morris
,
Mathew
Savage
,
Timothy
Easun
,
Pascal
Manuel
,
Claire
Murray
,
Chiu
Tang
,
Mark
Frogley
,
Gianfelice
Cinque
,
Sihai
Yang
Diamond Proposal Number(s):
[15972, 13666]
Open Access
Abstract: MFM‐300(Al) shows reversible uptake of NH3 (15.7 mmol g‐1 at 273 K and 1.0 bar) over 50 cycles with an exceptional packing density of 0.62 g cm‐3 at 293 K. In situ neutron powder diffraction and synchrotron FTIR micro‐spectroscopy on ND3@MFM‐300(Al) confirms reversible H/D site exchange between the adsorbent and adsorbate, representing a new type of adsorption interaction.
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Aug 2018
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B22-Multimode InfraRed imaging And Microspectroscopy
|
Nicholas M.
Jacques
,
Peter R. E.
Rought
,
Detlev
Fritsch
,
Mathew
Savage
,
Harry G. W.
Godfrey
,
Lei
Li
,
Tamoghna
Mitra
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sihai
Yang
,
Martin
Schroder
Diamond Proposal Number(s):
[17709]
Abstract: The binding domains within a mixed matrix membrane (MMM) that is selective for CO2 comprising MFM-300(Al) and the polymer 6FDA-Durene-DABA have been established via in situ synchrotron IR microspectroscopy. The MOF crystals are fully accessible and play a critical role in the binding of CO2, creating a selective pathway to promote permeation of CO2 within and through the MMM. This study reveals directly the molecular mechanism for the overall enhanced performance of this MMM in terms of permeability, solubility and selectivity for CO2.
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Mar 2018
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I19-Small Molecule Single Crystal Diffraction
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Iñigo J.
Vitórica-Yrezábal
,
Daniel Florin
Sava
,
Grigore A.
Timco
,
Martyn S.
Brown
,
Mathew
Savage
,
Harry G. W.
Godfrey
,
Florian
Moreau
,
Martin
Schroeder
,
Flor
Siperstein
,
Lee
Brammer
,
Sihai
Yang
,
Martin P.
Attfield
,
Joseph J. W.
Mcdouall
,
Richard E. P.
Winpenny
Abstract: The {Cr8} metallacrown [CrF(O2CtBu)2]8, containing a F-lined internal cavity, shows high selectivity for CO2 over N2. DFT calculations and absorption studies support the multiple binding of F-groups to the C-center of CO2 (C⋅⋅⋅F 3.190(9)–3.389(9) Å), as confirmed by single-crystal X-ray diffraction.
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May 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
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Zhenzhong
Lu
,
Harry G. W.
Godfrey
,
Ivan
Da Silva
,
Yongqiang
Cheng
,
Mathew
Savage
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Simon J.
Teat
,
Kevin J.
Gagnon
,
Mark D.
Frogley
,
Pascal
Manuel
,
Svemir
Rudic
,
Anibal J.
Ramirez-Cuesta
,
Timothy L.
Easun
,
Sihai
Yang
,
Martin
Schröder
Diamond Proposal Number(s):
[13666]
Open Access
Abstract: Hydrogen bonds dominate many chemical and biological processes, and chemical modification enables control and modulation of host–guest systems. Here we report a targeted modification of hydrogen bonding and its effect on guest binding in redox-active materials. MFM-300(VIII) {[VIII2(OH)2(L)], LH4=biphenyl-3,3′,5,5′-tetracarboxylic acid} can be oxidized to isostructural MFM-300(VIV), [VIV2O2(L)], in which deprotonation of the bridging hydroxyl groups occurs. MFM-300(VIII) shows the second highest CO2 uptake capacity in metal-organic framework materials at 298 K and 1 bar (6.0 mmol g−1) and involves hydrogen bonding between the OH group of the host and the O-donor of CO2, which binds in an end-on manner, =1.863(1) Å. In contrast, CO2-loaded MFM-300(VIV) shows CO2 bound side-on to the oxy group and sandwiched between two phenyl groups involving a unique ···c.g.phenyl interaction [3.069(2), 3.146(3) Å]. The macroscopic packing of CO2 in the pores is directly influenced by these primary binding sites.
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Jan 2017
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
I19-Small Molecule Single Crystal Diffraction
|
Mathew
Savage
,
Yongqiang
Cheng
,
Timothy L.
Easun
,
Jennifer E.
Eyley
,
Stephen P.
Argent
,
Mark
Warren
,
William
Lewis
,
Claire
Murray
,
Chiu C.
Tang
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Junliang
Sun
,
Svemir
Rudić
,
Richard T.
Murden
,
Michael J.
Benham
,
Andrew N.
Fitch
,
Alexander J.
Blake
,
Anibal J.
Ramirez-Cuesta
,
Sihai
Yang
,
Martin
Schröder
Diamond Proposal Number(s):
[9444, 5839, 12516]
Open Access
Abstract: Selective adsorption of SO2 is realized in a porous metal–organic framework material, and in-depth structural and spectroscopic investigations using X-rays, infrared, and neutrons define the underlying interactions that cause SO2 to bind more strongly than CO2 and N2.
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Aug 2016
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I11-High Resolution Powder Diffraction
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Mathew
Savage
,
Ivan
Da Silva
,
Mark
Johnson
,
Joseph H.
Carter
,
Ruth
Newby
,
Mikhail
Suyetin
,
Elena
Besley
,
Pascal
Manuel
,
Svemir
Rudić
,
Andrew N.
Fitch
,
Claire
Murray
,
William
David
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[5839]
Abstract: The key requirement for a portable store of natural gas is to maximize the amount of gas within the smallest possible space. The packing of methane (CH4) in a given storage medium at the highest possible density is, therefore, a highly desirable but challenging target. We report a microporous hydroxyl-decorated material, MFM-300(In) (MFM = Manchester Framework Material, replacing the NOTT designation), which displays a high volumetric uptake of 202 v/v at 298 K and 35 bar for CH4 and 488 v/v at 77 K and 20 bar for H2. Direct observation and quantification of the location, binding, and rotational modes of adsorbed CH4 and H2 molecules within this host have been achieved, using neutron diffraction and inelastic neutron scattering experiments, coupled with density functional theory (DFT) modeling. These complementary techniques reveal a very efficient packing of H2 and CH4 molecules within MFM-300(In), reminiscent of the condensed gas in pure component crystalline solids. We also report here, for the first time, the experimental observation of a direct binding interaction between adsorbed CH4 molecules and the hydroxyl groups within the pore of a material. This is different from the arrangement found in CH4/water clathrates, the CH4 store of nature.
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Jul 2016
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