B18-Core EXAFS
B22-Multimode InfraRed imaging And Microspectroscopy
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Wanpeng
Lu
,
Claudia E.
Tait
,
Gokay
Avci
,
Xian'E
Li
,
Agamemnon E.
Crumpton
,
Paul
Shao
,
Catherine M.
Aitchison
,
Fabien
Ceugniet
,
Yuyun
Yao
,
Mark D.
Frogley
,
Donato
Decarolis
,
Nan
Yao
,
Kim E.
Jelfs
,
Iain
Mcculloch
Open Access
Abstract: With the pressing urgency to reduce carbon footprint, photocatalytic carbon dioxide reduction has attracted growing attention as a sustainable mitigating option. Considering the important role of catalytic active sites (CASs) in the catalytic processes, control and design of the density and environment of CASs could enhance the catalyst performance. Herein, we report a novel metal–covalent organic framework (MCOF), MCOF-Co-315, featuring earth-abundant Co cocatalysts and conjugation through a covalently bonded backbone. MCOF-Co-315 showed a CO production rate of 1616 μmol g–1 h–1 utilizing Ru(bpy)3Cl2 as photosensitizer and triethanolamine (TEOA) as sacrificial electron donor with a 1.5 AM filter, vis mirror module (390–740 nm), and irradiation intensity adjusted to 1 sun and an especially outstanding apparent quantum yield (AQY) of 9.13% at 450 nm. The photocatalytic reaction was studied with electron paramagnetic resonance (EPR) spectroscopy, X-ray absorption near-edge structure (XANES), and in situ synchrotron Fourier Transform Infrared (FT-IR) spectroscopy, and an underlying mechanism is proposed.
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Mar 2025
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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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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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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
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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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B22-Multimode InfraRed imaging And Microspectroscopy
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Lixia
Guo
,
Joseph
Hurd
,
Meng
He
,
Wanpeng
Lu
,
Jiangnan
Li
,
Danielle
Crawshaw
,
Mengtian
Fan
,
Sergey A.
Sapchenko
,
Yinlin
Chen
,
Xiangdi
Zeng
,
Meredydd
Kippax-Jones
,
Wenyuan
Huang
,
Zhaodong
Zhu
,
Pascal
Manuel
,
Mark D.
Frogley
,
Daniel
Lee
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[30398]
Open Access
Abstract: The development of stable sorbent materials to deliver reversible adsorption of ammonia (NH3) is a challenging task. Here, we report the efficient capture and storage of NH3 in a series of robust microporous aluminium-based metal-organic framework materials, namely MIL-160, CAU-10-H, Al-fum, and MIL-53(Al). In particular, MIL-160 shows high uptakes of NH3 of 4.8 and 12.8 mmol g−1 at both low and high pressure (0.001 and 1.0 bar, respectively) at 298 K. The combination of in situ neutron powder diffraction, synchrotron infrared micro-spectroscopy and solid-state nuclear magnetic resonance spectroscopy reveals the preferred adsorption domains of NH3 molecules in MIL-160, with H/D site-exchange between the host and guest and an unusual distortion of the local structure of [AlO6] moieties being observed. Dynamic breakthrough experiments confirm the excellent ability of MIL-160 to capture of NH3 with a dynamic uptake of 4.2 mmol g−1 at 1000 ppm. The combination of high porosity, pore aperture size and multiple binding sites promotes the significant binding affinity and capacity for NH3, which makes it a promising candidate for practical applications.
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Mar 2023
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
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Jiangnan
Li
,
Gemma L.
Smith
,
Yinlin
Chen
,
Yujie
Ma
,
Meredydd
Kippax-Jones
,
Mengtian
Fan
,
Wanpeng
Lu
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Sarah
Day
,
Stephen P.
Thompson
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Anibal J.
Ramirez-Cuetos
,
Martin
Schroeder
,
Sihai
Yang
Diamond Proposal Number(s):
[28497, 29649]
Open Access
Abstract: We report reversible high capacity adsorption of SO2 in robust Zr-based metal-organic frameworks (MOFs). Zr-bptc (H4bptc = biphenyl-3,3’,5,5’-tetracarboxylic acid) shows a high SO2 uptake of 6.2 mmol g-1 at 0.1 bar and 298 K, reflecting excellent capture capability and removal of SO2 at low concentration (2500 ppm). Dynamic breakthrough experiments confirm that the introduction of amine, atomically-dispersed Cu(II) or heteroatomic sulphur sites into the pores enhance the capture of SO2 at low concentrations. The captured SO2 can be converted quantitatively to a pharmaceutical intermediate, aryl N-aminosulfonamide, thus converting waste to chemical values. In situ X-ray diffraction, infrared micro-spectroscopic and inelastic neutron scattering enable the visualisation of the binding domains of adsorbed SO2 molecules and host-guest binding dynamics in these materials at the atomic level. The refinement of pore environment plays a critical role in designing efficient sorbent materials.
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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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