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
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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I11-High Resolution Powder Diffraction
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Xiangdi
Zeng
,
Zi
Wang
,
Meng
He
,
Wanpeng
Lu
,
Wenyuan
Huang
,
Bing
An
,
Jiangnan
Li
,
Mufan
Li
,
Ben F.
Spencer
,
Sarah J.
Day
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[37155]
Open Access
Abstract: Phenylacetylene is a detrimental impurity in the polymerisation of styrene, capable of poisoning catalysts even at ppm levels and significantly degrading the quality of polystyrene. The semi-hydrogenation of phenylacetylene to styrene instead of ethylbenzene is, therefore, an important industrial process. We report a novel cerium(IV)-based metal-organic framework (denoted as Ce-bptc), which is comprised of {Ce6} clusters bridged by biphenyl-3,3’,5,5’-tetracarboxylate linkers. Ce-bptc serves as an ideal support for palladium nanoparticles and the Pd@Ce-bptc catalyst demonstrates an excellent catalytic performance for semi-hydrogenation of phenylacetylene, achieving a selectivity of 93% to styrene on full conversion under ambient conditions with excellent reusability. In situ synchrotron X-ray powder diffraction and electron paramagnetic resonance spectroscopy revealed the binding domain of phenylacetylene within Ce-bptc and details of the reaction mechanism.
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Oct 2024
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B22-Multimode InfraRed imaging And Microspectroscopy
I15-1-X-ray Pair Distribution Function (XPDF)
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Wanpeng
Lu
,
Yinlin
Chen
,
Zi
Wang
,
Jin
Chen
,
Yujie
Ma
,
Weiyao
Li
,
Jiangnan
Li
,
Meng
He
,
Mengtian
Fan
,
Alena M.
Sheveleva
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Mark D.
Frogley
,
Philip A.
Chater
,
Catherine
Dejoie
,
Martin
Schroder
,
Sihai
Yang
,
Lixia
Guo
Open Access
Abstract: The development of materials for ammonia (NH3) storage is an important and challenging task. Here, we report the high NH3 uptake in a series of copper-carboxylate materials, namely MFM-100, MFM-101, MFM-102, MFM-126, MFM-127, MFM-190(F), MFM-170, and Cu-MOP-1a. At 273 K and 1 bar, MFM-101 shows an exceptional uptake of 21.9 mmol g−1. X-ray pair distribution function analysis reveals an unusual crystalline-amorphous-crystalline phase transition for the isoreticular MFM-100, MFM-101 and MFM-102 upon adsorption and desorption of NH3 followed by regeneration in water. In situ X-ray diffraction, synchrotron infrared micro-spectroscopy, and electron paramagnetic resonance spectroscopy are employed to elucidate the presence of strong Cu(II)⋯NH3 interactions and changes in coordination at the [Cu2(O2CR)4] (R = di-, tri-, and tetra-phenyl ligands) paddlewheel.
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Sep 2024
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Lutong
Shan
,
Yujie
Ma
,
Shaojun
Xu
,
Meng
Zhou
,
Meng
He
,
Alena M.
Sheveleva
,
Rongsheng
Cai
,
Daniel
Lee
,
Yongqiang
Chen
,
Boya
Tang
,
Bing
Han
,
Yinlin
Chen
,
Lan
An
,
Tianze
Zhou
,
Martin
Wilding
,
Alexander S.
Eggeman
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sarah J.
Day
,
Stephen P.
Thompson
,
Sarah J.
Haigh
,
Xinchen
Kang
,
Buxing
Han
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[33115, 31729]
Open Access
Abstract: The design and preparation of efficient catalysts for ammonia production under mild conditions is a desirable but highly challenging target. Here, we report a series of single-atom catalysts [M-SACs, M = Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Mo(II)] derived from UiO-66 containing structural defects and their application to electrochemical reduction of nitrate (NO3-) to ammonia (NH3). Cu-SAC and Fe-SAC exhibit remarkable yield rates for NH3 production of 30.0 and 29.0 mg h−1 cm−2, respectively, with a high Faradaic efficiency (FENH3) of over 96% at −1.0 V versus the reversible hydrogen electrode. Importantly, their catalytic performance can be retained in various simulated wastewaters. Complementary experiments confirmed the nature of single-atom sites within these catalysts and the binding domains of NO3- in UiO-66-Cu. In situ spectroscopic techniques, coupled with density functional theory calculations confirm the strong binding of NO3- and the formation of reaction intermediates, thus facilitating the catalytic conversion to NH3.
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Jun 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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B22-Multimode InfraRed imaging And Microspectroscopy
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Diamond Proposal Number(s):
[22137, 30398]
Open Access
Abstract: Metal–organic framework (MOF) materials are attracting increasing interest in the field of electronics due to their structural diversity, intrinsic porosity, and designable host–guest interactions. Here, we report the dielectric properties of a series of robust materials, MFM-300(M) (M = Al, Sc, Cr, Fe, Ga, In), when exposed to different guest molecules. MFM-300(Fe) exhibits the most notable increase in dielectric constant to 35.3 ± 0.3 at 10 kHz upon adsorption of NH3. Structural analysis suggests that the electron delocalization induced by host–guest interactions between NH3 and the MOF host, as confirmed by neutron powder diffraction studies, leads to structural polarization, resulting in a high dielectric constant for NH3@MFM-300(Fe). This is further supported by ligand-to-metal charge-transfer transitions observed by solid-state UV/vis spectroscopy. The high detection sensitivity and stability to NH3 suggest that MFM-300(Fe) may act as a powerful dielectric-based sensor for NH3.
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Oct 2023
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Wenyaun
Huang
,
Qingqing
Mei
,
Shaojun
Xu
,
Bing
An
,
Meng
He
,
Jiangnan
Li
,
Yinlin
Chen
,
Xue
Han
,
Tian
Luo
,
Lixia
Guo
,
Joseph
Hurd
,
Daniel
Lee
,
Evan
Tillotson
,
Sarah
Haigh
,
Alex
Walton
,
Sarah
Day
,
Louise S.
Natrjan
,
Martin
Schroeder
,
Sihai
Yang
Open Access
Abstract: Formamides are important feedstocks for the manufacture of many fine chemicals. State-of-the-art synthesis of formamides relies on the use of an excess amount of reagents, giving copious waste and thus poor atom-economy. Here, we report the first example of direct synthesis of N-formamides by coupling two challenging reactions, namely reductive amination of carbonyl compounds, particularly biomass-derived aldehydes and ketones, and fixation of CO2 in the presence of H2 over a metal-organic framework supported ruthenium catalyst, Ru/MFM-300(Cr). Highly selective production of N-formamides has been observed for a wide range of carbonyl compounds. Synchrotron X-ray powder diffraction reveals the presence of strong host-guest binding interactions via hydrogen bonding and parallel-displaced π···π interactions between the catalyst and adsorbed substrates facilitating the activation of substrates and promoting selectivity to formamides. The use of multifunctional porous catalysts to integrate CO2 utilisation in the synthesis of formamide products will have a significant impact in the sustainable synthesis of feedstock chemicals.
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Oct 2023
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I19-Small Molecule Single Crystal Diffraction
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Mei-Yan
Gao
,
Andrey A.
Bezrukov
,
Bai-Qiao
Song
,
Meng
He
,
Sousa Javan
Nikkhah
,
Shi-Qiang
Wang
,
Naveen
Kumar
,
Shaza
Darwish
,
Debobroto
Sensharma
,
Chenghua
Deng
,
Jiangnan
Li
,
Lunjie
Liu
,
Rajamani
Krishna
,
Matthias
Vandichel
,
Sihai
Yang
,
Michael J.
Zaworotko
Open Access
Abstract: Ultramicroporous materials can be highly effective at trace gas separations when they offer a high density of selective binding sites. Herein, we report that sql-NbOFFIVE-bpe-Cu, a new variant of a previously reported ultramicroporous square lattice, sql, topology material, sql-SIFSIX-bpe-Zn, can exist in two polymorphs. These polymorphs, sql-NbOFFIVE-bpe-Cu-AA (AA) and sql-NbOFFIVE-bpe-Cu-AB (AB), exhibit AAAA and ABAB packing of the sql layers, respectively. Whereas NbOFFIVE-bpe-Cu-AA (AA) is isostructural with sql-SIFSIX-bpe-Zn, each exhibiting intrinsic 1D channels, sql-NbOFFIVE-bpe-Cu-AB (AB) has two types of channels, the intrinsic channels and extrinsic channels between the sql networks. Gas and temperature induced transformations of the two polymorphs of sql-NbOFFIVE-bpe-Cu were investigated by pure gas sorption, single-crystal X-ray diffraction (SCXRD), variable temperature powder X-ray diffraction (VT-PXRD), and synchrotron PXRD. We observed that the extrinsic pore structure of AB resulted in properties with potential for selective C3H4/C3H6 separation. Subsequent dynamic gas breakthrough measurements revealed exceptional experimental C3H4/C3H6 selectivity (270) and a new benchmark for productivity (118 mmol g–1) of polymer grade C3H6 (purity >99.99%) from a 1:99 C3H4/C3H6 mixture. Structural analysis, gas sorption studies, and gas adsorption kinetics enabled us to determine that a binding “sweet spot” for C3H4 in the extrinsic pores is behind the benchmark separation performance. Density-functional theory (DFT) calculations and Canonical Monte Carlo (CMC) simulations provided further insight into the binding sites of C3H4 and C3H6 molecules within these two hybrid ultramicroporous materials, HUMs. These results highlight, to our knowledge for the first time, how pore engineering through the study of packing polymorphism in layered materials can dramatically change the separation performance of a physisorbent.
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May 2023
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