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
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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B07-B1-Versatile Soft X-ray beamline: High Throughput ES1
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Ziyu
Cen
,
Xue
Han
,
Longfei
Lin
,
Sihai
Yang
,
Wanying
Han
,
Weilong
Wen
,
Wenli
Yuan
,
Minghua
Dong
,
Zhiye
Ma
,
Fang
Li
,
Yubin
Ke
,
Juncai
Dong
,
Jin
Zhang
,
Shuhu
Liu
,
Jialiang
Li
,
Qian
Li
,
Ningning
Wu
,
Junfeng
Xiang
,
Hao
Wu
,
Lile
Cai
,
Yanbo
Hou
,
Yongqiang
Chen
,
Luke L.
Daemen
,
Anibal J.
Ramirez-Cuesta
,
Pilar
Ferrer
,
David C.
Grinter
,
Georg
Held
,
Yueming
Liu
,
Buxing
Han
Diamond Proposal Number(s):
[33962]
Open Access
Abstract: Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable to commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling experiments reveal that the activation of polyethylene is promoted by the open framework tri-coordinated Al sites of the zeolite, followed by β-scission and isomerization on Brönsted acids sites, accompanied by hydride transfer over open framework tri-coordinated Al sites through a self-supplied hydrogen pathway to yield selectivity to branched alkanes. This study shows the potential of layered zeolite materials in enabling the upcycling of plastic wastes.
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Apr 2024
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I11-High Resolution Powder Diffraction
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Martin
Schroeder
,
Christopher
Marsh
,
Xue
Han
,
Zhenzhong
Lu
,
Ivan
Da Silva
,
Yongqiang
Chen
,
Luke L.
Daemen
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Anibal Javier
Ramirez-Cuesta
,
Sihai
Yang
Open Access
Abstract: The functionalisation of organic linkers in metal-organic frameworks (MOFs) to improve gas uptake is well-documented. Although the positive role of free carboxylic acid sites in MOFs for binding gas molecules has been proposed in computational studies, relatively little experimental evidence has been reported in support of this. Primarily this is because of the inherent synthetic difficulty to prepare MOF materials bearing free, accessible –COOH moieties which would normally bind to metal ions within the framework structure. Here, we describe the direct binding of CO2 and C2H2 molecules to the free -COOH sites within the pores of MFM-303(Al). MFM-303(Al) exhibits highly selective adsorption of CO2 and C2H2 with a high selectivity for C2H2 over C2H4. In situ synchrotron X-ray diffraction and inelastic neutron scattering, coupled with modelling, highlight the cooperative interactions of adsorbed CO2 and C2H2 molecules with free -COOH and -OH sites within MFM-303(Al), thus rationalising the observed high selectivity for gas separation.
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Apr 2024
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B18-Core EXAFS
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Yujie
Ma
,
Xue
Han
,
Shaojun
Xu
,
Zhe
Li
,
Wanpeng
Lu
,
Bing
An
,
Daniel
Lee
,
Sarayute
Chansai
,
Alena M.
Sheveleva
,
Zi
Wang
,
Yinlin
Chen
,
Jiangnan
Li
,
Weiyao
Li
,
Rongsheng
Cai
,
Ivan
Da Silva
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Lewis
Hughes
,
Pascal
Manuel
,
Anibal J.
Ramirez-Cuesta
,
Sarah J.
Haigh
,
Christopher
Hardacre
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[19850]
Open Access
Abstract: Conversion of methane (CH4) to ethylene (C2H4) and/or acetylene (C2H2) enables routes to a wide range of products directly from natural gas. However, high reaction temperatures and pressures are often required to activate and convert CH4 controllably, and separating C2+ products from unreacted CH4 can be challenging. Here, we report the direct conversion of CH4 to C2H4 and C2H2 driven by non-thermal plasma under ambient (25 °C and 1 atm) and flow conditions over a metal–organic framework material, MFM-300(Fe). The selectivity for the formation of C2H4 and C2H2 reaches 96% with a high time yield of 334 μmol gcat–1 h–1. At a conversion of 10%, the selectivity to C2+ hydrocarbons and time yield exceed 98% and 2056 μmol gcat–1 h–1, respectively, representing a new benchmark for conversion of CH4. In situ neutron powder diffraction, inelastic neutron scattering and solid-state nuclear magnetic resonance, electron paramagnetic resonance (EPR), and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modeling studies, reveal the crucial role of Fe–O(H)–Fe sites in activating CH4 and stabilizing reaction intermediates via the formation of an Fe–O(CH3)–Fe adduct. In addition, a cascade fixed-bed system has been developed to achieve online separation of C2H4 and C2H2 from unreacted CH4 for direct use. Integrating the processes of CH4 activation, conversion, and product separation within one system opens a new avenue for natural gas utility, bridging the gap between fundamental studies and practical applications in this area.
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Sep 2023
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I11-High Resolution Powder Diffraction
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Zi
Wang
,
Alena M.
Sheveleva
,
Daniel
Lee
,
Yinlin
Chen
,
Dinu
Iuga
,
W. Trent
Franks
,
Yujie
Ma
,
Jiangnan
Li
,
Lei
Li
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Sarah J.
Day
,
Anibal J.
Ramirez-Cuesta
,
Bing
Han
,
Alexander S.
Eggeman
,
Eric J. L.
Mcinnes
,
Floriana
Tuna
,
Sihai
Yang
,
Martin
Schroeder
Open Access
Abstract: We report the modulation of reactivity of nitrogen dioxide (NO2) in a charged metal-organic framework (MOF) material, MFM-305-CH3 in which unbound N-centres are methylated and the cationic charge counter-balanced by Cl− ions in the pores. Uptake of NO2 into MFM-305-CH3 leads to reaction between NO2 and Cl– to give nitrosyl chloride (NOCl) and NO3− anions. A high dynamic uptake of 6.58 mmol g−1 at 298 K is observed for MFM-305-CH3 as measured using a flow of 500 ppm NO2 in He. In contrast, the analogous neutral material, MFM-305, shows a much lower uptake of 2.38 mmol g−1. The binding domains and reactivity of adsorbed NO2 molecules within MFM-305-CH3 and MFM-305 have been probed using in situ synchrotron X-ray diffraction, inelastic neutron scattering and by electron paramagnetic resonance, high-field solid-state nuclear magnetic resonance and UV-vis spectroscopies. The design of charged porous sorbents provides a new platform to control the reactivity of corrosive air pollutants.
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Apr 2023
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I11-High Resolution Powder Diffraction
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Jiangnan
Li
,
Zi
Wang
,
Yinlin
Chen
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sarah J.
Day
,
Anibal J.
Ramirez-Cuesta
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[31365]
Open Access
Abstract: Increasing levels of air pollution are driving the need for the development of new processes that take “waste-to-chemicals”. Herein, we report the capture and conversion under ambient conditions of a major air pollutant, NO2, using a robust metal-organic framework (MOF) material, Zr-bptc (H4bptc = 3,3′,5,5′-biphenyltetracarboxylic acid), comprising {Zr6(μ3-O)4(μ3-OH)4(COO)12} clusters linked by 4-connected bptc4– ligands in an ftw topology. At 298 K, Zr-bptc shows exceptional stability and adsorption of NO2 at both low (4.9 mmol g–1 at 10 mbar) and high pressures (13.8 mmol g–1 at 1.0 bar), as measured by isotherm experiments. Dynamic breakthrough experiments have confirmed the selective retention of NO2 by Zr-bptc at low concentrations under both dry and wet conditions. The immobilized NO2 can be readily transformed into valuable nitro compounds relevant to construction, agrochemical, and pharmaceutical industries. In situ crystallographic and spectroscopic studies reveal strong binding interactions of NO2 to the {Zr6(μ3-O)4(μ3-OH)4(COO)12} cluster node. This study paves a circular pathway to enable the integration of nitrogen-based air pollutants into the production of fine chemicals.
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Oct 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
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Bing
An
,
Zhe
Li
,
Zi
Wang
,
Xiangdi
Zeng
,
Xue
Han
,
Yongqiang
Chen
,
Alena M.
Sheveleva
,
Zhongyue
Zhang
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Mark D.
Frogley
,
Anibal J.
Ramirez-Cuesta
,
Louise S.
Natrajan
,
Cheng
Wang
,
Wenbin
Li
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[23782]
Abstract: Natural gas, consisting mainly of methane (CH4), has a relatively low energy density at ambient conditions (~36 kJ l−1). Partial oxidation of CH4 to methanol (CH3OH) lifts the energy density to ~17 MJ l−1 and drives the production of numerous chemicals. In nature, this is achieved by methane monooxygenase with di-iron sites, which is extremely challenging to mimic in artificial systems due to the high dissociation energy of the C–H bond in CH4 (439 kJ mol−1) and facile over-oxidation of CH3OH to CO and CO2. Here we report the direct photo-oxidation of CH4 over mono-iron hydroxyl sites immobilized within a metal–organic framework, PMOF-RuFe(OH). Under ambient and flow conditions in the presence of H2O and O2, CH4 is converted to CH3OH with 100% selectivity and a time yield of 8.81 ± 0.34 mmol gcat−1 h−1 (versus 5.05 mmol gcat−1 h−1 for methane monooxygenase). By using operando spectroscopic and modelling techniques, we find that confined mono-iron hydroxyl sites bind CH4 by forming an [Fe–OH···CH4] intermediate, thus lowering the barrier for C–H bond activation. The confinement of mono-iron hydroxyl sites in a porous matrix demonstrates a strategy for C–H bond activation in CH4 to drive the direct photosynthesis of CH3OH.
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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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