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Water‐Stable Zirconium‐Based Metal–Organic Framework Material with High‐Surface Area and Gas‐Storage Capacities 下载免费PDF全文
Dr. Oleksii V. Gutov Dr. Wojciech Bury Dr. Diego A. Gomez‐Gualdron Dr. Vaiva Krungleviciute Dr. David Fairen‐Jimenez Dr. Joseph E. Mondloch Dr. Amy A. Sarjeant Salih S. Al‐Juaid Prof. Dr. Randall Q. Snurr Prof. Dr. Joseph T. Hupp Prof. Dr. Taner Yildirim Prof. Dr. Omar K. Farha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12389-12393
We designed, synthesized, and characterized a new Zr‐based metal–organic framework material, NU‐1100 , with a pore volume of 1.53 ccg?1 and Brunauer–Emmett–Teller (BET) surface area of 4020 m2g?1; to our knowledge, currently the highest published for Zr‐based MOFs. CH4/CO2/H2 adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 g g?1, which corresponds to 43 g L?1. The volumetric and gravimetric methane‐storage capacities at 65 bar and 298 K are approximately 180 vSTP/v and 0.27 g g?1, respectively. 相似文献
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Chiral Metal–Organic Framework Hollow Nanospheres for High‐Efficiency Enantiomer Separation 下载免费PDF全文
Xiaoshi Wang Yanan Zhu Jian Liu Chang Liu Prof. Changyan Cao Prof. Weiguo Song 《化学:亚洲杂志》2018,13(12):1535-1538
Chiral ZIF‐8 hollow nanospheres with d ‐histidine as part of chiral ligands (denoted as H‐d ‐his‐ZIF‐8) were prepared for separation of (±)‐amine acids. Compared to bulk d ‐his‐ZIF‐8 without a hollow cavity, the prepared H‐d ‐his‐ZIF‐8 showed 15 times higher separation capacity and higher ee values of 90.5 % for alanine, 95.2 % for glutamic acid and 92.6 % for lysine, respectively. 相似文献
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Flexible and Hierarchical Metal–Organic Framework Composites for High‐Performance Catalysis 下载免费PDF全文
Dr. Ning Huang Hannah Drake Jialuo Li Dr. Jiandong Pang Dr. Ying Wang Shuai Yuan Qi Wang Peiyu Cai Dr. Junsheng Qin Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2018,57(29):8916-8920
The development of porous composite materials is of great significance for their potentially improved performance over those of individual components and extensive applications in separation, energy storage, and heterogeneous catalysis. Now mesoporous metal–organic frameworks (MOFs) with macroporous melamine foam (MF) have been integrated using a one‐pot process, generating a series of MOF/MF composite materials with preserved crystallinity, hierarchical porosity, and increased stability over that of melamine foam. The MOF nanocrystals were threaded by the melamine foam networks, resembling a ball‐and‐stick model overall. The resulting MOF/MF composite materials were employed as an effective heterogeneous catalyst for the epoxidation of cholesteryl esters. Combining the advantages of interpenetrative mesoporous and macroporous structures, the MOF/melamine foam composite has higher dispersibility and more accessibility of catalytic sites, exhibiting excellent catalytic performance. 相似文献
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Thomas Wittmann Dr. Renée Siegel Nele Reimer Dr. Wolfgang Milius Prof. Dr. Norbert Stock Prof. Dr. Jürgen Senker 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):314-323
The resistance of metal–organic frameworks towards water is a very critical issue concerning their practical use. Recently, it was shown for microporous MOFs that the water stability could be increased by introducing hydrophobic pendant groups. Here, we demonstrate a remarkable stabilisation of the mesoporous MOF Al‐MIL‐101‐NH2 by postsynthetic modification with phenyl isocyanate. In this process 86 % of the amino groups were converted into phenylurea units. As a consequence, the long‐term stability of Al‐MIL‐101‐URPh in liquid water could be extended beyond a week. In water saturated atmospheres Al‐MIL‐101‐URPh decomposed at least 12‐times slower than the unfunctionalised analogue. To study the underlying processes both materials were characterised by Ar, N2 and H2O sorption measurements, powder X‐ray diffraction, thermogravimetric and chemical analysis as well as solid‐state NMR and IR spectroscopy. Postsynthetic modification decreased the BET equivalent surface area from 3363 to 1555 m2 g?1 for Al‐MIL‐101‐URPh and reduced the mean diameters of the mesopores by 0.6 nm without degrading the structure significantly and reducing thermal stability. In spite of similar water uptake capacities, the relative humidity‐dependent uptake of Al‐MIL‐101‐URPh is slowed and occurs at higher relative humidity values. In combination with 1H‐27Al D ‐HMQC NMR spectroscopy experiments this favours a shielding mechanism of the Al clusters by the pendant phenyl groups and rules out pore blocking. 相似文献
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Dr. Maykel de Miguel Mrs. Florence Ragon Prof. Thomas Devic Prof. Christian Serre Prof. Patricia Horcajada Prof. Hermenegildo García 《Chemphyschem》2012,13(16):3651-3654
Herein, we describe the photochemical behavior of the porous metal–organic framework MIL‐125(Ti)‐NH2, built up from cyclic Ti8O8(OH)4 oxoclusters and 2‐aminoterephthalate ligands. While MIL‐125(Ti)‐NH2 does not emit upon excitation at 420 nm, laser flash photolyses of dry samples (diffuse reflectance) or aqueous suspensions (transmission) of the solid have allowed detecting a transient characterized by a continuous absorption from 390 to 820 nm decaying in the sub‐millisecond timescale, which is quenched by oxygen. This transient has been attributed to the charge‐separation state. Firm evidence for this assignment was obtained by lamp irradiation of aqueous suspensions of MIL‐125(Ti)‐NH2 in the presence of electron‐donor (N,N,N′N′‐tetramethyl‐p‐phenylenediamine) or electron‐acceptor (methylviologen) probe molecules, which has allowed the visual detection of the corresponding radical ions, in agreement with the occurrence of photoinduced charge separation in MIL‐125(Ti)‐NH2. 相似文献
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Fluorocarbon Separation in a Thermally Robust Zirconium Carboxylate Metal–Organic Framework 下载免费PDF全文
Fluorocarbons have important applications in industry, but are environmentally unfriendly, and can cause ozone depletion and contribute to the global warming with long atmospheric lifetimes and high global warming potential. In this work, the metal–organic framework UiO‐66(Zr) is demonstrated to have excellent performance characteristics to separate fluorocarbon mixtures at room temperature. Adsorption isotherm measurements of UiO‐66(Zr) display high fluorocarbon sorption uptakes of 5.0 mmol g?1 for R22 (CHClF2), 4.6 mmol g?1 for R125 (CHF2CF3), and 2.9 mmol g?1 for R32 (CH2F2) at 298 K and 1 bar. Breakthrough data obtained for binary (R22/R32 and R32/R125) and ternary (R32/R125/R134a) mixtures reveal high selectivities and capacities of UiO‐66(Zr) for the separation and recycling of these fluorocarbon mixtures. Furthermore, the UiO‐66(Zr) saturated with R22 and R125 can be regenerated at temperatures as low as 120 °C with excellent desorption–adsorption cycling stabilities. 相似文献
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Microporous metal–organic frameworks (MOFs) are comparatively new porous materials. Because the pores within such MOFs can be readily tuned through the interplay of both metal‐containing clusters and organic linkers to induce their size‐selective sieving effects, while the pore surfaces can be straightforwardly functionalized to enforce their different interactions with gas molecules, MOF materials are very promising for gas separation. Furthermore, the high porosities of such materials can enable microporous MOFs with optimized gas separation selectivity and capacity to be targeted. This Focus Review highlights recent significant advances in microporous MOFs for gas separation. 相似文献
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Ultrathin Chiral Metal–Organic‐Framework Nanosheets for Efficient Enantioselective Separation 下载免费PDF全文
Jun Guo Yin Zhang Yanfei Zhu Chang Long Dr. Meiting Zhao Prof. Meng He Xiaofei Zhang Jiawei Lv Prof. Bing Han Prof. Zhiyong Tang 《Angewandte Chemie (International ed. in English)》2018,57(23):6873-6877
Chiral metal–organic framework (CMOF) nanosheets only a few layers thick remain a virgin land waiting for exploration. Herein, the first examples of ultrathin CMOF nanosheets are prepared by the confinement growth of two‐dimensional (2D) chiral layers, which are assembled by helical metal–organic chains within microemulsion. This convenient and easily scaled up inverse microemulsion method gives a series of 2D CMOF nanosheets composed of variable metal nodes or chiral ligands. More significantly, thanks to the exceptionally large number of chiral sites exposed on surfaces, the as‐obtained CMOF nanosheets exhibit much higher enantioselectivity in chiral separation compared with their bulk counterparts. 相似文献
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High‐Flux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchange 下载免费PDF全文
Moon Joo Lee Dr. Hyuk Taek Kwon Prof. Dr. Hae‐Kwon Jeong 《Angewandte Chemie (International ed. in English)》2018,57(1):156-161
While zeolitic imidazolate framework, ZIF‐8, membranes show impressive propylene/propane separation, their throughput needs to be greatly improved for practical applications. A method is described that drastically reduces the effective thickness of ZIF‐8 membranes, thereby substantially improving their propylene permeance (that is, flux). The new strategy is based on a controlled single‐crystal to single‐crystal linker exchange of 2‐methylimidazole in ZIF‐8 membrane grains with 2‐imidazolecarboxaldehyde (ZIF‐90 linker), thereby enlarging the effective aperture size of ZIF‐8. The linker‐exchanged ZIF‐8 membranes showed a drastic increase in propylene permeance by about four times, with a negligible loss in propylene/propane separation factor when compared to as‐prepared membranes. The linker‐exchange effect depends on the membrane synthesis method. 相似文献
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Eleftheria Neofotistou Christos D. Malliakas Dr. Pantelis N. Trikalitis Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(18):4523-4527
Gas storage : A new, sulfone‐functionalized dicarboxylate‐based ligand (see figure) is capable of directing the formation of novel metal–organic frameworks with unprecedented organic and inorganic secondary building units. A high CO2 uptake with remarkable selectivity over CH4, N2, and H2 was observed at near‐ambient temperature.
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Template‐based Synthesis of a Formate Metal–Organic Framework/Activated Carbon Fiber Composite for High‐performance Methane Adsorptive Separation 下载免费PDF全文
Xiao‐Wei Liu Jiang‐Liang Hu Dr. Tian‐Jun Sun Ya Guo Dr. Thomas D. Bennett Xin‐Yu Ren Prof. Dr. Shu‐Dong Wang 《化学:亚洲杂志》2016,11(21):3014-3017
Simultaneous improvement in adsorption selectivity and capacity for single adsorbents is challenging but counting for much in adsorptive separations. To this end, a formate metal–organic framework and activated carbon fiber composite was synthesized in our work by a simple two‐step process, involving homogeneous precipitation of a MOF precursor on an activated carbon fiber and subsequent template replication. The resultant core–shell composite, ACF@[Ni3(HCOO)6], exhibited optimized adsorption performance both in selectivity and capacity for the separation of CH4/N2 to most of state‐of‐the‐art adsorbents. 相似文献
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Effect of Functionalized Groups on Gas‐Adsorption Properties: Syntheses of Functionalized Microporous Metal–Organic Frameworks and Their High Gas‐Storage Capacity 下载免费PDF全文
Yanlong Wang Chunhong Tan Zhihao Sun Zhenzhen Xue Dr. Qilong Zhu Dr. Chaojun Shen Dr. Yuehong Wen Dr. Shengmin Hu Yong Wang Prof. Tianlu Sheng Prof. Xintao Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1341-1348
The microporous metal–organic framework (MMOF) Zn4O(L1)2 ? 9 DMF ? 9 H2O ( 1‐H ) and its functionalized derivatives Zn4O(L1‐CH3)2 ? 9 DMF ? 9 H2O ( 2‐CH3 ) and Zn4O(L1‐Cl)2 ? 9 DMF ? 9 H2O ( 3‐Cl ) have been synthesized and characterized (H3L1=4‐[N,N‐bis(4‐methylbenzoic acid)amino]benzoic acid, H3L1‐CH3=4‐[N,N‐bis(4‐methylbenzoic acid)amino]‐2‐methylbenzoic acid, H3L1‐Cl=4‐[N,N‐bis(4‐methylbenzoic acid)amino]‐2‐chlorobenzoic acid). Single‐crystal X‐ray diffraction analyses confirmed that the two functionalized MMOFs are isostructural to their parent MMOF, and are twofold interpenetrated three‐dimensional (3D) microporous frameworks. All of the samples possess enduring porosity with Langmuir surface areas over 1950 cm2 g?1. Their pore volumes and surface areas decrease in the order 1‐H > 2‐CH3 > 3‐Cl . Gas‐adsorption studies show that the H2 uptakes of these samples are among the highest of the MMOFs (2.37 wt % for 3‐Cl at 77 K and 1 bar), although their structures are interpenetrating. Furthermore, this work reveals that the adsorbate–adsorbent interaction plays a more important role in the gas‐adsorption properties of these samples at low pressure, whereas the effects of the pore volumes and surface areas dominate the gas‐adsorption properties at high pressure. 相似文献
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Konrad Hindelang Alexander Kronast Dr. Sergei I. Vagin Prof. Bernhard Rieger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8244-8252
For the first time, the adaptability of the C?C double bond as a versatile precursor for the postsynthetic modification (PSM) of microporous materials was extensively investigated and evaluated. Therefore, an olefin‐tagged 4,4′‐bipyridine linker was synthesized and successfully introduced as pillar linker within a 9,10‐triptycenedicarboxylate (TDC) zinc paddle‐wheel metal–organic framework (MOF) through microwave‐assisted synthesis. Different reactions, predominately used in organic chemistry, were tested, leading to the development of new postsynthetic reactions for the functionalization of solid materials. The postsynthetic oxidation of the olefin side groups applying osmium tetroxide (OsO4) as a catalyst led to the formation of a microporous material with free vicinal diol functionalities. The epoxidation with dimethyldioxirane (DMDO) enabled the synthesis of epoxy‐functionalized MOFs. In addition to that, reaction procedures for a postsynthetic hydroboration with borane dimethyl sulfide as well as a photoinduced thiol–ene click reaction with ethyl mercaptan were developed. For all of these PSMs, yields of more than 90 % were obtained, entirely maintaining the crystallinity of the MOFs. Since the direct introduction of the corresponding groups by means of pre‐synthetic approaches is hardly possible, these new PSMs are useful tools for the functionalization of porous solids towards applications such as selective adsorption, separation, and catalysis. 相似文献
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A Robust Metal–Organic Framework for Dynamic Light‐Induced Swing Adsorption of Carbon Dioxide 下载免费PDF全文
Dr. Haiqing Li Dr. Marta Rubio Martinez Zachary Perry Prof. Hong‐Cai Zhou Prof. Paolo Falcaro Dr. Christian Doblin Dr. Seng Lim Dr. Anita J. Hill Dr. Barry Halstead Dr. Matthew R. Hill 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11176-11179
Adsorbents for CO2 capture need to demonstrate efficient release. Light‐induced swing adsorption (LISA) is an attractive new method to release captured CO2 that utilizes solar energy rather than electricity. MOFs, which can be tailored for use in LISA owing to their chemical functionality, are often unstable in moist atmospheres, precluding their use. A MOF is used that can release large quantities of CO2 via LISA and is resistant to moisture across a large pH range. PCN‐250 undergoes LISA, with UV flux regulating the CO2 desorption capacity. Furthermore, under UV light, the azo residues within PCN‐250 have constrained, local, structural flexibility. This is dynamic, rapidly switching back to the native state. Reusability tests demonstrate a 7.3 % and 4.9 % loss in both adsorption and LISA capacity after exposure to water for five cycles. These minimal changes confirm the structural robustness of PCN‐250 and its great potential for triggered release applications. 相似文献