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Qi
Xue
,
Ching Kit Tommy
Wun
,
Tianxiang
Chen
,
Shogo
Kawaguchi
,
Sarah
Day
,
Chiu C.
Tang
,
Tai-Sing
Wu
,
Yun-Liang
Soo
,
Cong
Lin
,
Yung-Kang
Peng
,
Jun
Yin
,
Tsz Woon Benedict
Lo
Abstract: Supported bimetallic dual-atom catalysts (DACs) have been regarded as a promising class of materials for small molecule activation, but their syntheses remain challenging. Here, we report the controlled synthesis of supported Cu,Fe DACs on the ZrO6O4 secondary building units of UiO-66-NH2 which allows the efficient activation of O2. Remarkably high product selectivity (>92%) towards benzaldehyde over our model photocatalytic styrene oxidation reaction has been achieved. The superior reactivity has been attributed to the well-balanced synergy between the electronic and steric characteristics, which enables efficient O2 activation by the sterically restrained Cu and Fe sites in proximity for the formation of the bridging peroxy group. This bridging peroxy group facilitates the selective oxidation of styrene akin to many peroxide-based oxidants. The confined microporous environment allows the control of the electronic and geometric properties of the DACs, which subsequently sheds light towards more precise atomistic engineering that approaches the conventional inorganic metal(s)-complex counterparts.
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May 2023
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Tianxiang
Chen
,
Wenhua
Yu
,
Ching Kit Tommy
Wun
,
Tai-Sing
Wu
,
Mingzi
Sun
,
Sarah J.
Day
,
Zehao
Li
,
Bo
Yuan
,
Yong
Wang
,
Mingjie
Li
,
Zi
Wang
,
Yung-Kang
Peng
,
Wing-Yiu
Yu
,
Kwok-Yin
Wong
,
Bolong
Huang
,
Taoyuan
Liang
,
Tsz Woon Benedict
Lo
Abstract: A cross-coupling reaction via the dehydrogenative route over heterogeneous solid atomic catalysts offers practical solutions toward an economical and sustainable elaboration of simple organic substrates. The current utilization of this technology is, however, hampered by limited molecular definition of many solid catalysts. Here, we report the development of Cu–M dual-atom catalysts (where M = Co, Ni, Cu, and Zn) supported on a hierarchical USY zeolite to mediate efficient dehydrogenative cross-coupling of unprotected phenols with amine partners. Over 80% isolated yields have been attained over Cu–Co–USY, which shows much superior reactivity when compared with our Cu1 and other Cu–M analogues. This amination reaction has hence involved simple and non-forceful reaction condition requirements. The superior reactivity can be attributed to (1) the specifically designed bimetallic Cu–Co active sites within the micropore for “co-adsorption–co-activation” of the reaction substrates and (2) the facile intracrystalline (meso/micropore) diffusion of the heterocyclic organic substrates. This study offers critical insights into the engineering of next-generation solid atomic catalysts with complex reaction steps.
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Apr 2023
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I11-High Resolution Powder Diffraction
|
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
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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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
|
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
|
Bixian
Ying
,
Jack R.
Fitzpatrick
,
Zhenjie
Teng
,
Tianxiang
Chen
,
Tsz Woon Benedict
Lo
,
Vassilios
Siozios
,
Claire A.
Murray
,
Helen E. A.
Brand
,
Sarah
Day
,
Chiu C.
Tang
,
Robert S.
Weatherup
,
Peter
Nagel
,
Stefan
Schuppler
,
Martin
Winter
,
Karin
Kleiner
,
Michael
Merz
Diamond Proposal Number(s):
[19772]
Open Access
Abstract: The syntheses of Ni-poor (NCM111, LiNi1/3Co1/3Mn1/3O2) and Ni-rich (NCM811 LiNi0.8Co0.1Mn0.1O2) lithium transition-metal oxides (space group R3̅m) from hydroxide precursors (Ni1/3Co1/3Mn1/3(OH)2, Ni0.8Co0.1Mn0.1(OH)2) are investigated using in situ synchrotron powder diffraction and near-edge X-ray absorption fine structure spectroscopy. The development of the layered structure of these two cathode materials proceeds via two utterly different reaction mechanisms. While the synthesis of NCM811 involves a rock salt-type intermediate phase, NCM111 reveals a layered structure throughout the entire synthesis. Moreover, the necessity and the impact of a preannealing step and a high-temperature holding step are discussed.
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Jan 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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|
I11-High Resolution Powder Diffraction
|
Ching Kit Tommy
Wun
,
Ho Kit
Mok
,
Tianxiang
Chen
,
Tai-Sing
Wu
,
Keita
Taniya
,
Keizo
Nakagawa
,
Sarah
Day
,
Chiu C.
Tang
,
Ziru
Huang
,
Haibin
Su
,
Wing-Yiu
Yu
,
Terence Kin Wah
Lee
,
Tsz Woon Benedict
Lo
Diamond Proposal Number(s):
[24677, 28907]
Abstract: Solid atomic catalysts with well-defined and complex structures are believed to effectively bridge homogeneous and heterogeneous catalysis. Nonetheless, the current limited capacity of “precise engineering” in solid atomic catalysts has led to structural heterogeneity and thus unsatisfactory catalytic selectivity. Here, we show that late 3d metal cations, such as Co2+, Ni2+, Cu2+, and Zn2+, can be assembled to afford combinations of “dual atoms” within zeolitic micropores, and this clearly avoids issues like uncontrolled metal aggregation during synthesis. In this work, by the quantitative evaluation of the structural descriptors over a probe superoxide dismutation reaction, we demonstrate the unique synergistic advantage between (i) neighboring bimetallic active motifs, (ii) tertiary structure around the zeolitic support, and (iii) the local coordination environment. The identification and tunability of the structural descriptors shown in this work unravel a reliable approach to the precise engineering of next-generation solid dual-atom catalysts.
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Aug 2022
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B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
|
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
I11-High Resolution Powder Diffraction
|
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
|
|
I11-High Resolution Powder Diffraction
|
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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