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1.
Qihao Yang Chun‐Chuen Yang Chia‐Her Lin Hai‐Long Jiang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3549-3553
The development of efficient and low energy‐consumption catalysts for CO2 conversion is desired, yet remains a great challenge. Herein, a class of novel hollow porous carbons (HPC), featuring well dispersed dopants of nitrogen and single Zn atoms, have been fabricated, based on the templated growth of a hollow metal–organic framework precursor, followed by pyrolysis. The optimized HPC‐800 achieves efficient catalytic CO2 cycloaddition with epoxides, under light irradiation, at ambient temperature, by taking advantage of an ultrahigh loading of (11.3 wt %) single‐atom Zn and uniform N active sites, high‐efficiency photothermal conversion as well as the hierarchical pores in the carbon shell. As far as we know, this is the first report on the integration of the photothermal effect of carbon‐based materials with single metal atoms for catalytic CO2 fixation. 相似文献
2.
《Angewandte Chemie (International ed. in English)》2017,56(20):5512-5516
Hollow metal–organic frameworks (MOFs) are promising materials with sophisticated structures, such as multiple shells, that cannot only enhance the properties of MOFs but also endow them with new functions. Herein, we show a rational strategy to fabricate multi‐shelled hollow chromium (III) terephthalate MOFs (MIL‐101) with single‐crystalline shells through step‐by‐step crystal growth and subsequent etching processes. This strategy relies on the creation of inhomogeneous MOF crystals in which the outer layer is chemically more robust than the inner layer and can be selectively etched by acetic acid. The regulation of MOF nucleation and crystallization allows the tailoring of the cavity size and shell thickness of each layer. The resultant multi‐shelled hollow MIL‐101 crystals show significantly enhanced catalytic activity during styrene oxidation. The insight gained from this systematic study will aid in the rational design and synthesis of other multi‐shelled hollow structures and the further expansion of their applications. 相似文献
3.
Zhicheng Zhang Yifeng Chen Xiaobin Xu Jingchao Zhang Guolei Xiang Wei He Prof. Xun Wang 《Angewandte Chemie (International ed. in English)》2014,53(2):429-433
Metal–organic frameworks (MOFs) have demonstrated great potentials in a variety of important applications. To enhance the inherent properties and endow materials with multifunctionality, the rational design and synthesis of MOFs with nanoscale porosity and hollow feature is highly desired and remains a great challenge. In this work, the formation of a series of well‐defined MOF (MOF‐5, FeII‐MOF‐5, FeIII‐MOF‐5) hollow nanocages by a facile solvothermal method, without any additional supporting template is reported. A surface‐energy‐driven mechanism may be responsible for the formation of hollow nanocages. The addition of pre‐synthesized poly(vinylpyrrolidone)‐ (PVP) capped noble‐metal nanoparticles into the synthetic system of MOF hollow nanocages yields the yolk–shell noble metal@MOF nanostructures. The present strategy to fabricate hollow and yolk–shell nanostructures is expected to open up exciting opportunities for developing a novel class of inorganic–organic hybrid functional nanomaterials. 相似文献
4.
Efficient Visible‐Light‐Driven Carbon Dioxide Reduction by a Single‐Atom Implanted Metal–Organic Framework 下载免费PDF全文
Dr. Huabin Zhang Dr. Jing Wei Dr. Juncai Dong Dr. Guigao Liu Li Shi Dr. Pengfei An Dr. Guixia Zhao Dr. Jintao Kong Dr. Xiaojun Wang Dr. Xianguang Meng Prof. Jing Zhang Prof. Jinhua Ye 《Angewandte Chemie (International ed. in English)》2016,55(46):14310-14314
Modular optimization of metal–organic frameworks (MOFs) was realized by incorporation of coordinatively unsaturated single atoms in a MOF matrix. The newly developed MOF can selectively capture and photoreduce CO2 with high efficiency under visible‐light irradiation. Mechanistic investigation reveals that the presence of single Co atoms in the MOF can greatly boost the electron–hole separation efficiency in porphyrin units. Directional migration of photogenerated excitons from porphyrin to catalytic Co centers was witnessed, thereby achieving supply of long‐lived electrons for the reduction of CO2 molecules adsorbed on Co centers. As a direct result, porphyrin MOF comprising atomically dispersed catalytic centers exhibits significantly enhanced photocatalytic conversion of CO2, which is equivalent to a 3.13‐fold improvement in CO evolution rate (200.6 μmol g?1 h?1) and a 5.93‐fold enhancement in CH4 generation rate (36.67 μmol g?1 h?1) compared to the parent MOF. 相似文献
5.
Chengdong Peng Xueling Song Jinlin Yin Guiyang Zhang Honghan Fei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7900-7904
The secondary building units in metal–organic frameworks (MOFs) are commonly well‐defined metal–oxo clusters or chains with very limited structural strain. Herein, the structurally deformable haloplumbate units that are often observed in organolead halide perovskites have been successfully incorporated into MOFs. The resultant materials are a rare class of isoreticular MOFs exhibiting large Stokes‐shifted broadband white‐light emission, which is probably induced by self‐trapped excitons from electron–phonon coupling in the deformable, zigzag [Pb2X3]+ (X=Cl, Br, or I) chains. In contrast, MOFs with highly symmetric, robust haloplumbate chains only exhibit narrow UV–blue photoemission. The designed MOF‐based intrinsic white‐light photoemitters have a number of advantages over hybrid inorganic–organic perovskites in terms of stability and tunability, including moisture resistance, facile functionalization of photoactive moieties onto the organic linkers, introduction of luminescent guests. 相似文献
6.
Silica‐Protection‐Assisted Encapsulation of Cu2O Nanocubes into a Metal–Organic Framework (ZIF‐8) To Provide a Composite Catalyst 下载免费PDF全文
Bo Li Dr. Jian‐Gong Ma Prof. Dr. Peng Cheng 《Angewandte Chemie (International ed. in English)》2018,57(23):6834-6837
The integration of metal/metal oxide nanoparticles (NPs) into metal–organic frameworks (MOFs) to form composite materials has attracted great interest due to the broad range of applications. However, to date, it has not been possible to encapsulate metastable NPs with high catalytic activity into MOFs, due to their instability during the preparation process. For the first time, we have successfully developed a template protection–sacrifice (TPS) method to encapsulate metastable NPs such as Cu2O into MOFs. SiO2 was used as both a protective shell for Cu2O nanocubes and a sacrificial template for forming a yolk–shell structure. The obtained Cu2O@ZIF‐8 composite exhibits excellent cycle stability in the catalytic hydrogenation of 4‐nitrophenol with high activity. This is the first report of a Cu2O@MOF‐type composite material. The TPS method provides an efficient strategy for encapsulating unstable active metal/metal oxide NPs into MOFs or maybe other porous materials. 相似文献
7.
Synthesis of Supported Ultrafine Non‐noble Subnanometer‐Scale Metal Particles Derived from Metal–Organic Frameworks as Highly Efficient Heterogeneous Catalysts 下载免费PDF全文
Xinchen Kang Prof. Huizhen Liu Dr. Minqiang Hou Xiaofu Sun Hongling Han Prof. Tao Jiang Dr. Zhaofu Zhang Prof. Buxing Han 《Angewandte Chemie (International ed. in English)》2016,55(3):1080-1084
The properties of supported non‐noble metal particles with a size of less than 1 nm are unknown because their synthesis is a challenge. A strategy has now been created to immobilize ultrafine non‐noble metal particles on supports using metal–organic frameworks (MOFs) as metal precursors. Ni/SiO2 and Co/SiO2 catalysts were synthesized with an average metal particle size of 0.9 nm. The metal nanoparticles were immobilized uniformly on the support with a metal loading of about 20 wt %. Interestingly, the ultrafine non‐noble metal particles exhibited very high activity for liquid‐phase hydrogenation of benzene to cyclohexane even at 80 °C, while Ni/SiO2 with larger Ni particles fabricated by a conventional method was not active under the same conditions. 相似文献
8.
Mohammad Yaser Masoomi Ali Morsali Amarajothi Dhakshinamoorthy Hermenegildo Garcia 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15330-15347
Mixed‐metal metal–organic frameworks (MM‐MOFs) can be considered to be those MOFs having two different metals anywhere in the structure. Herein we summarize the various strategies for the preparation of MM‐MOFs and some of their applications in adsorption, gas separation, and catalysis. It is shown that compared to homometallic MOFs, MM‐MOFs bring about the opportunity to take advantage of the complexity and the synergism derived from the presence of different metal ions in the structure of MOFs. This is reflected in a superior performance and even stability of MM‐MOFs respect to related single‐metal MOFs. Emphasis is made on the use of MM‐MOFs as catalysts for tandem reactions. 相似文献
9.
Ping Peng Fang‐Fang Li Venkata S. Pavan K. Neti Alejandro J. Metta‐Magana Luis Echegoyen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(1):164-167
Given the unique structural and electronic properties of C60, metal–organic frameworks (MOFs) containing C60 linkers are expected to exhibit interesting characteristics. A new hexakisfullerene derivative possessing two pairs of phenyl pyridine groups attached to two methano‐carbon atoms located at the trans‐1 positions was designed and synthesized. The four pyridyl nitrogen atoms define a perfectly planar rectangle. This new C60 derivative was used to assemble the first fullerene‐linked two‐dimensional MOF by coordination with Cd2+. 相似文献
10.
Design,Synthesis, and X‐Ray Crystal Structure of a Fullerene‐Linked Metal–Organic Framework 下载免费PDF全文
Dr. Ping Peng Dr. Fang‐Fang Li Venkata S. Pavan K. Neti Dr. Alejandro J. Metta‐Magana Prof. Dr. Luis Echegoyen 《Angewandte Chemie (International ed. in English)》2014,53(1):160-163
Given the unique structural and electronic properties of C60, metal–organic frameworks (MOFs) containing C60 linkers are expected to exhibit interesting characteristics. A new hexakisfullerene derivative possessing two pairs of phenyl pyridine groups attached to two methano‐carbon atoms located at the trans‐1 positions was designed and synthesized. The four pyridyl nitrogen atoms define a perfectly planar rectangle. This new C60 derivative was used to assemble the first fullerene‐linked two‐dimensional MOF by coordination with Cd2+. 相似文献
11.
Hollow Zn/Co ZIF Particles Derived from Core–Shell ZIF‐67@ZIF‐8 as Selective Catalyst for the Semi‐Hydrogenation of Acetylene 下载免费PDF全文
Jian Yang Fengjun Zhang Haiyuan Lu Xun Hong Hailong Jiang Yuen Wu Yadong Li 《Angewandte Chemie (International ed. in English)》2015,54(37):10889-10893
The rational design of metal–organic frameworks (MOFs) with hollow features and tunable porosity at the nanoscale can enhance their intrinsic properties and stimulates increasing attentions. In this Communication, we demonstrate that methanol can affect the coordination mode of ZIF‐67 in the presence of Co2+ and induces a mild phase transformation under solvothermal conditions. By applying this transformation process to the ZIF‐67@ZIF‐8 core–shell structures, a well‐defined hollow Zn/Co ZIF rhombic dodecahedron can be obtained. The manufacturing of hollow MOFs enables us to prepare a noble metal@MOF yolk‐shell composite with controlled spatial distribution and morphology. The enhanced gas storage and porous confinement that originate from the hollow interior and coating of ZIF‐8 confers this unique catalyst with superior activity and selectivity toward the semi‐hydrogenation of acetylene. 相似文献
12.
Dengrong Sun Praveen Reddy Adiyala Se‐Jun Yim Dong‐Pyo Kim 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(22):7483-7487
Hydrophobization of metal‐organic frameworks (MOFs) is important to push forward their practical use and thus has attracted increasing interest. In contrast to the previous reports, which mainly focused on the modification of organic ligands in MOFs, herein, we reported a novel strategy to decorate the metal‐oxo nodes of MOFs with phenylsilane to afford super‐hydrophobic NH2‐UiO‐66(Zr), which shows highly improved base resistance and holds great promise in versatile applications, such as organic/water separation, self‐cleaning, and liquid‐marble fabrication. This work demonstrates the first attempt at metal‐oxo node modification for super‐hydrophobic MOFs, advancing a new concept in the design of MOFs with controlled wettability for practical applications. 相似文献
13.
Time‐Resolved In Situ X‐ray Diffraction Reveals Metal‐Dependent Metal–Organic Framework Formation 下载免费PDF全文
Dr. Yue Wu Dr. Sebastian Henke Dr. Gregor Kieslich Inke Schwedler Dr. Miaosen Yang Duncan A. X. Fraser Prof. Dermot O'Hare 《Angewandte Chemie (International ed. in English)》2016,55(45):14081-14084
Versatility in metal substitution is one of the key aspects of metal‐organic framework (MOF) chemistry, allowing properties to be tuned in a rational way. As a result, it important to understand why MOF syntheses involving different metals arrive at or fail to produce the same topological outcome. Frequently, conditions are tuned by trial‐and‐error to make MOFs with different metal species. We ask: is it possible to adjust synthetic conditions in a systematic way in order to design routes to desired phases? We have used in situ X‐ray powder diffraction to study the solvothermal formation of isostructural M2(bdc)2dabco (M=Zn, Co, Ni) pillared‐paddlewheel MOFs in real time. The metal ion strongly influences both kinetics and intermediates observed, leading in some cases to multiphase reaction profiles of unprecedented complexity. The standard models used for MOF crystallization break down in these cases; we show that a simple kinetic model describes the data and provides important chemical insights on phase selection. 相似文献
14.
Ayjamal Ablet Shu‐Mu Li Wei Cao Dr. Xiang‐Jun Zheng Prof. Wing‐Tak Wong Prof. Lin‐Pei Jin 《化学:亚洲杂志》2013,8(1):95-100
Four new three‐dimensional isostructural lanthanide–cadmium metal–organic frameworks (Ln–Cd MOFs), [LnCd2(imdc)2(Ac)(H2O)2]?H2O (Ln=Pr ( 1 ), Eu ( 2 ), Gd ( 3 ), and Tb ( 4 ); H3imdc=4,5‐imidazoledicarboxylic acid; Ac=acetate), have been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, inductively coupled plasma (ICP) analysis, and X‐ray diffraction. Single‐crystal X‐ray diffraction shows that two LnIII ions are surrounded by four CdII ions to form a heteronuclear building block. The blocks are further linked to form 3D Ln–Cd MOFs by the bridging imdc3? ligand. Furthermore, the left‐ and right‐handed helices array alternatively in the lattice. Eu–Cd and Tb–Cd MOFs can emit characteristic red light with the EuIII ion and green light with the TbIII ion, respectively, while both Gd–Cd and Pr–Cd MOFs generate blue emission when they are excited. Different concentrations of Eu3+ and Tb3+ ions were co‐doped into Gd–Cd/Pr–Cd MOFs, and tunable luminescence from yellow to white was achieved. White‐light emission was obtained successfully by adjusting the excitation wavelength or the co‐doping ratio of the co‐doped Gd–Cd and Pr–Cd MOFs. These results show that the relative emission intensity of white light for Gd–Cd:Eu3+,Tb3+ MOFs is stronger than that of Pr–Cd:Eu3+,Tb3+ MOFs, which implies that the Gd complex is a better matrix than the Pr complex to obtain white‐light emission materials. 相似文献
15.
Weijia Wang Dmitry I. Sharapa Abhinav Chandresh Alexei Nefedov Stefan Heißler Lars Heinke Felix Studt Yuemin Wang Christof Wll 《Angewandte Chemie (International ed. in English)》2020,59(26):10514-10518
In contrast to catalytically active metal single atoms deposited on oxide nanoparticles, the crystalline nature of metal‐organic frameworks (MOFs) allows for a thorough characterization of reaction mechanisms. Using defect‐free HKUST‐1 MOF thin films, we demonstrate that Cu+/Cu2+ dimer defects, created in a controlled fashion by reducing the pristine Cu2+/Cu2+ pairs of the intact framework, account for the high catalytic activity in low‐temperature CO oxidation. Combining advanced IR spectroscopy and density functional theory we propose a new reaction mechanism where the key intermediate is an uncharged O2 species, weakly bound to Cu+/Cu2+. Our results reveal a complex interplay between electronic and steric effects at defect sites in MOFs and provide important guidelines for tailoring and exploiting the catalytic activity of single metal atom sites. 相似文献
16.
Dr. In Soo Kim Dr. Zhanyong Li Dr. Jian Zheng Dr. Ana E. Platero‐Prats Dr. Andreas Mavrandonakis Dr. Steven Pellizzeri Dr. Magali Ferrandon Aleksei Vjunov Dr. Leighanne C. Gallington Thomas E. Webber Dr. Nicolaas A. Vermeulen Prof. R. Lee Penn Prof. Rachel B. Getman Prof. Christopher J. Cramer Dr. Karena W. Chapman Dr. Donald M. Camaioni Dr. John L. Fulton Prof. Johannes A. Lercher Prof. Omar K. Farha Prof. Joseph T. Hupp Dr. Alex B. F. Martinson 《Angewandte Chemie (International ed. in English)》2018,57(4):909-913
Single atoms and few‐atom clusters of platinum are uniformly installed on the zirconia nodes of a metal‐organic framework (MOF) NU‐1000 via targeted vapor‐phase synthesis. The catalytic Pt clusters, site‐isolated by organic linkers, are shown to exhibit high catalytic activity for ethylene hydrogenation while exhibiting resistance to sintering up to 200 °C. In situ IR spectroscopy reveals the presence of both single atoms and few‐atom clusters that depend upon synthesis conditions. Operando X‐ray absorption spectroscopy and X‐ray pair distribution analyses reveal unique changes in chemical bonding environment and cluster size stability while on stream. Density functional theory calculations elucidate a favorable reaction pathway for ethylene hydrogenation with the novel catalyst. These results provide evidence that atomic layer deposition (ALD) in MOFs is a versatile approach to the rational synthesis of size‐selected clusters, including noble metals, on a high surface area support. 相似文献
17.
Zhong Wei Jiang Yang Chun Zou Ting Ting Zhao Shu Jun Zhen Yuan Fang Li Cheng Zhi Huang 《Angewandte Chemie (International ed. in English)》2020,59(8):3300-3306
Synthesizing 2D metal–organic frameworks (2D MOFs) in high yields and rational tailoring of the properties in a predictable manner for specific applications is extremely challenging. Now, a series of porphyrin‐based 2D lanthanide MOFs (Ln‐TCPP, Ln=Ce, Sm, Eu, Tb, Yb, TCPP=tetrakis(4‐carboxyphenyl) porphyrin) with different thickness were successfully prepared in a household microwave oven. The as‐prepared 2D Ln‐TCPP nanosheets showed thickness‐dependent photocatalytic performances towards photooxidation of 1,5‐dihydroxynaphthalene (1,5‐DHN) to synthesize juglone. Particularly, the Yb‐TCPP displayed outstanding photodynamic activity to generate O2? and 1O2. This work not only provides fundamental insights into structure designing and property tailoring of 2D MOFs nanosheets, but also pave a new way to improve the photocatalytic performance. 相似文献
18.
Weiren Cheng Xue Feng Lu Deyan Luan Xiong Wen Lou 《Angewandte Chemie (International ed. in English)》2020,59(41):18234-18239
Developing noble‐metal‐free bifunctional oxygen electrocatalysts is of great significance for energy conversion and storage systems. Herein, we have developed a transformation method for growing NiMn‐based bimetal–organic framework (NiMn‐MOF) nanosheets on multi‐channel carbon fibers (MCCF) as a bifunctional oxygen electrocatalyst. Owing to the desired components and architecture, the MCCF/NiMn‐MOFs manifest comparable electrocatalytic performance towards oxygen reduction reaction (ORR) with the commercial Pt/C electrocatalyst and superior performance towards oxygen evolution reaction (OER) to the benchmark RuO2 electrocatalyst. X‐ray absorption fine structure (XAFS) spectroscopy and density functional theory (DFT) calculations reveal that the strong synergetic effect of adjacent Ni and Mn nodes within MCCF/NiMn‐MOFs effectively promotes the thermodynamic formation of key *O and *OOH intermediates over active NiO6 centers towards fast ORR and OER kinetics. 相似文献
19.
Yongqiang Zhao Tao Ling Shuangming Chen Bo Jin Anthony Vasileff Yan Jiao Li Song Jun Luo Shi‐Zhang Qiao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(35):12380-12385
Common‐metal‐based single‐atom catalysts (SACs) are quite difficult to design due to the complex synthesis processes required. Herein, we report a single‐atom nickel iodide (SANi‐I) electrocatalyst with atomically dispersed non‐metal iodine atoms. The SANi‐I is prepared via a simple calcination step in a vacuum‐sealed ampoule and subsequent cyclic voltammetry activation. Aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy and synchrotron‐based X‐ray absorption spectroscopy are applied to confirm the atomic‐level dispersion of iodine atoms and detailed structure of SANi‐I. Single iodine atoms are found to be isolated by oxygen atoms. The SANi‐I is structural stable and shows exceptional electrocatalytic activity for the hydrogen evolution reaction (HER). In situ Raman spectroscopy reveals that the hydrogen adatom (Hads) is adsorbed by a single iodine atom, forming the I‐Hads intermediate, which promotes the HER process. 相似文献
20.
Dr. Jared B. DeCoste Dr. Joseph A. Rossin Gregory W. Peterson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18029-18032
The typically stable Zr‐based metal–organic frameworks (MOFs) UiO‐66 and UiO‐66‐NH2 were treated with tetrafluoromethane (CF4) and hexafluoroethane (C2F6) plasmas. Through interactions between fluoride radicals from the perfluoroalkane plasma and the zirconium–oxygen bonds of the MOF, the resulting materials showed the development of mesoporosity, creating a hierarchical pore structure. It is anticipated that this strategy can be used as a post‐synthetic technique for developing hierarchical networks in a variety of MOFs. 相似文献