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1.
A robust porous metal-organic framework (MOF), [Co(3)(ndc)(HCOO)(3)(μ(3)-OH)(H(2)O)](n) (1) (H(2)ndc=5-(4-pyridyl)-isophthalic acid), was synthesized with pronounced porosity. MOF 1 contained two different types of nanotubular channels, which exhibited a new topology with the Schlafli symbol of {4(2).6(5).8(3)}{4(2).6}. MOF 1 showed high-efficiency for the selective sorption of small molecules, including the energy-correlated gases of H(2), CH(4), and CO(2), and environment-correlated steams of alcohols, acetone, and pyridine. Gas-sorption experiments indicated that MOF 1 exhibited not only a high CO(2)-uptake (25.1 wt % at 273 K/1 bar) but also the impressive selective sorption of CO(2) over N(2) and CH(4). High H(2)-uptake (2.04 wt % at 77 K/1 bar) was also observed. Moreover, systematic studies on the sorption of steams of organic molecules displayed excellent capacity for the sorption of the homologous series of alcohols (C(1)-C(5)), acetone, pyridine, as well as water.  相似文献   

2.
The quantum mechanics (QM) method and grand canonical Monte Carlo (GCMC) simulations are used to study the effect of lithium cation doping on the adsorption and separation of CO2, CH4, and H2 on a twofold interwoven metal–organic framework (MOF), Zn2(NDC)2(diPyNI) (NDC=2,6‐naphthalenedicarboxylate; diPyNI=N,N′‐di‐(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide). Second‐order Moller–Plesset (MP2) calculations on the (Li+–diPyNI) cluster model show that the energetically most favorable lithium binding site is above the pyridine ring side at a distance of 1.817 Å from the oxygen atom. The results reveal that the adsorption capacity of Zn2(NDC)2(diPyNI) for carbon dioxide is higher than those of hydrogen and methane at room temperature. Furthermore, GCMC simulations on the structures obtained from QM calculations predict that the Li+‐doped MOF has higher adsorption capacities than the nondoped MOF, especially at low pressures. In addition, the probability density distribution plots reveal that CO2, CH4, and H2 molecules accumulate close to the Li cation site. The selectivity results indicate that CO2/H2 selectivity values in Zn2(NDC)2(diPyNI) are higher than those of CO2/CH4. The selectivity of CO2 over CH4 on Li+‐doped Zn2(NDC)2(diPyNI) is improved relative to the nondoped MOF.  相似文献   

3.
A three‐dimensional (3D) cage‐like organic network (3D‐CON) structure synthesized by the straightforward condensation of building blocks designed with gas adsorption properties is presented. The 3D‐CON can be prepared using an easy but powerful route, which is essential for commercial scale‐up. The resulting fused aromatic 3D‐CON exhibited a high Brunauer–Emmett–Teller (BET) specific surface area of up to 2247 m2 g?1. More importantly, the 3D‐CON displayed outstanding low pressure hydrogen (H2, 2.64 wt %, 1.0 bar and 77 K), methane (CH4, 2.4 wt %, 1.0 bar and 273 K), and carbon dioxide (CO2, 26.7 wt %, 1.0 bar and 273 K) uptake with a high isosteric heat of adsorption (H2, 8.10 kJ mol?1; CH4, 18.72 kJ mol?1; CO2, 31.87 kJ mol?1). These values are among the best reported for organic networks with high thermal stability (ca. 600 °C).  相似文献   

4.
A new metal‐organic framework (MOF) {[Cd2(bbib)2(ndc)2]?2DMF}n ( JXUST‐1 ) (bbib=1,3‐bis(benzimidazolyl)benzene, H2ndc=1,4‐naphthalenedicarboxylic acid, DMF=N,N‐dimethylformamide) has been solvothermally synthesized and characterized by single‐crystal X‐ray diffraction, PXRD, TGA, IR and elemental analysis. JXUST‐1 exhibits a three‐dimensional 6‐connected pcu topology with a Schläfli symbol {412.63} constructed by [Cd2(CO2)3] secondary building units. Fluorescence studies show that this MOF can sensitively and selectively recognize Al3+ via a fluorescence enhancement effect, and the detection limit is 0.048 ppm. Furthermore, JXUST‐1 displays relatively good thermal and chemical stabilities as well as reusability. All these results suggest JXUST‐1 to be a highly selective and recyclable luminescent sensing material for the detection of Al3+.  相似文献   

5.
A linear tetracarboxylic acid ligand, H4L, with a pendent amine moiety solvothermally forms two isostructural metal–organic frameworks (MOFs) LM (M=ZnII, CuII). Framework LCu can also be obtained from LZn by post‐ synthetic metathesis without losing crystallinity. Compared with LZn , the LCu framework exhibits high thermal stability and allows removal of guest solvent and metal‐bound water molecules to afford the highly porous, LCu′ . At 77 K, LCu′ absorbs 2.57 wt % of H2 at 1 bar, which increases significantly to 4.67 wt % at 36 bar. The framework absorbs substantially high amounts of methane (238.38 cm3 g?1, 17.03 wt %) at 303 K and 60 bar. The CH4 absorption at 303 K gives a total volumetric capacity of 166 cm3 (STP) cm?3 at 35 bar (223.25 cm3 g?1, 15.95 wt %). Interestingly, the NH2 groups in the linker, which decorate the channel surface, allow a remarkable 39.0 wt % of CO2 to be absorbed at 1 bar and 273 K, which comes within the dominion of the most famous MOFs for CO2 absorption. Also, LCu′ shows pronounced selectivity for CO2 absorption over CH4, N2, and H2 at 273 K. The absorbed CO2 can be converted to value‐added cyclic carbonates under relatively mild reaction conditions (20 bar, 120 °C). Finally, LCu′ is found to be an excellent heterogeneous catalyst in regioselective 1,3‐dipolar cycloaddition reactions (“click” reactions) and provides an efficient, economic route for the one‐pot synthesis of structurally divergent propargylamines through three‐component coupling of alkynes, amines, and aldehydes.  相似文献   

6.
We have used grand canonical Monte Carlo simulations with a first‐principles‐based force field to show that metal–organic frameworks (MOFs) with Li functional groups (i.e. C? Li bonds) allow for exceptional H2 uptake at ambient temperature. For example, at 298 K and 100 bar, IRMOF‐1‐4Li shows a total H2 uptake of 5.54 wt % and MOF‐200‐27Li exhibits a total H2 uptake of 10.30 wt %, which are much higher than the corresponding values with pristine MOFs. Li‐functionalized MOF‐200 (MOF‐200‐27Li) shows 11.84 wt % H2 binding at 243 K and 100 bar. These hydrogen‐storage capacities exceed the 2015 DOE target of 5.5 wt % H2. Moreover, the incorporation of Li functional groups into MOFs provides more benefits, such as higher delivery amount, for H2 uptake than previously reported Li‐doped MOFs.  相似文献   

7.
A novel 3D metal‐organic framework BSF‐1 based on the closo‐dodecaborate cluster [B12H12]2? was readily prepared at room temperature by supramolecular assembly of CuB12H12 and 1,2‐bis(4‐pyridyl)acetylene. The permanent microporous structure was studied by X‐ray crystallography, powder X‐ray diffraction, IR spectroscopy, thermogravimetric analysis, and gas sorption. The experimental and theoretical study of the gas sorption behavior of BSF‐1 for N2, C2H2, C2H4, CO2, C3H8, C2H6, and CH4 indicated excellent separation selectivities for C3H8/CH4, C2H6/CH4, and C2H2/CH4 as well as moderately high separation selectivities for C2H2/C2H4, C2H2/CO2, and CO2/CH4. Moreover, the practical separation performance of C3H8/CH4 and C2H6/CH4 was confirmed by dynamic breakthrough experiments. The good cyclability and high water/thermal stability render it suitable for real industrial applications.  相似文献   

8.
A metal–organic framework (NPC‐6) with an NbO topology based on a piperazine ring‐bridged diisophthalate ligand was synthesized and characterized. The incorporated piperazine group leads to an enhanced adsorption affinity for CO2 in NPC‐6, in which the CO2 uptake is 4.83 mmol g?1 at 293 K and 1 bar, ranking among the top values of CO2 uptake on MOF materials. At 0.15 bar and 293 K, the NPC‐6 adsorbs 1.07 mmol g?1 of CO2, which is about 55.1 % higher than that of the analogue MOF NOTT‐101 under the same conditions. The enhanced CO2 uptake combined with comparable uptakes for CH4 and N2 leads to much higher selectivities for CO2/CH4 and CO2/N2 gas mixtures on NPC‐6 than on NOTT‐101. Furthermore, an N‐alkylation is used in the synthesis of the PDIA ligand, leading to a much lower cost compared with that in the synthesis of ligands in the NOTT series, as the former does not require a palladium‐based catalyst and borate esters. Thus, we conclude that NPC‐6 is a promising candidate for CO2 capture applications.  相似文献   

9.
Here, we report two novel water‐stable amine‐functionalized MOFs, namely IISERP‐MOF26 ([NH2(CH3)2][Cu2O(Ad)(BDC)]?(H2O)2(DMA), 1 ) and IISERP‐MOF27 ([NH2(CH3)2]1/2[Zn4O(Ad)3(BDC)2]?(H2O)2(DMF)1/2, 2 ), which show selective CO2 capture capabilities. They are made by combining inexpensive and readily available terephthalic acid and N‐rich adenine with Cu and Zn, respectively. They possess 1D channels decorated by the free amine group from the adenine and the polarizing oxygen atoms from the terephthalate units. Even more, there are dimethyl ammonium (DMA+) cations in the pore rendering an electrostatic environment within the channels. The activated Cu‐ and Zn‐MOFs physisorb about 2.7 and 2.2 mmol g?1 of CO2, respectively, with high CO2/N2 and moderate CO2/CH4 selectivity. The calculated heat of adsorption (HOA=21–23 kJ mol?1) for the CO2 in both MOFs suggest optimal physical interactions which corroborate well with their facile on‐off cycling of CO2. Notably, both MOFs retain their crystallinity and porosity even after soaking in water for 24 hours as well as upon exposure to steam over 24 hours. The exceptional thermal and chemical stability, favorable CO2 uptakes and selectivity and low HOA make these MOFs promising sorbents for selective CO2 capture applications. However, the MOF′s low heat of adsorption despite having a highly CO2‐loving groups lined walls is quite intriguing.  相似文献   

10.
A rare, robust microporous lanthanide metal–organic framework with 1D honeycomb‐type channels is presented. Excellent adsorption capabilities for N2, H2, and CO2 and significant selective sorption of CO2 over N2 and CH4 were observed. Moreover, the guest‐dependent luminescent behavior of these lanthanide materials shows a potential use for the sensing of small‐molecule pollutants such as benzene and acetone.  相似文献   

11.
Four isostructural metal–organic frameworks (MOFs) with various functionalized pore surfaces were synthesized from a series of diisophthalate ligands. These MOFs exhibit a new network topology of {4.64.8}2{42.64}{64.82}2{66}. Hydrogen uptake as high as 2.67 wt % at 77 K/1 bar and CO2 uptake of 15.4 wt % at 297 K/1 bar have been observed for PCN‐308, which contains ? CF3 groups. The isostructural series of MOFs also showed reasonable adsorption selectivity of CO2 over CH4 and N2.  相似文献   

12.
The porous metal–organic framework (MOF) {[Zn2(TCPBDA)(H2O)2]?30 DMF?6 H2O}n ( SNU‐30 ; DMF=N,N‐dimethylformamide) has been prepared by the solvothermal reaction of N,N,N′,N′‐tetrakis(4‐carboxyphenyl)biphenyl‐4,4′‐diamine (H4TCPBDA) and Zn(NO3)2?6 H2O in DMF/tBuOH. The post‐synthetic modification of SNU‐30 by the insertion of 3,6‐di(4‐pyridyl)‐1,2,4,5‐tetrazine (bpta) affords single‐crystalline {[Zn2(TCPBDA)(bpta)]?23 DMF?4 H2O}n ( SNU‐31 SC ), in which channels are divided by the bpta linkers. Interestingly, unlike its pristine form, the bridging bpta ligand in the MOF is bent due to steric constraints. SNU‐31 can be also prepared through a one‐pot solvothermal synthesis from ZnII, TCPBDA4?, and bpta. The bpta linker can be liberated from this MOF by immersion in N,N‐diethylformamide (DEF) to afford the single‐crystalline SNU‐30 SC , which is structurally similar to SNU‐30 . This phenomenon of reversible insertion and removal of the bridging ligand while preserving the single crystallinity is unprecedented in MOFs. Desolvated solid SNU‐30′ adsorbs N2, O2, H2, CO2, and CH4 gases, whereas desolvated SNU‐31′ exhibits selective adsorption of CO2 over N2, O2, H2, and CH4, thus demonstrating that the gas adsorption properties of MOF can be modified by post‐synthetic insertion/removal of a bridging ligand.  相似文献   

13.
The sol‐gel metathesis reaction was used to synthesize a new family of aerogels called a rare‐earth chalcophosphate aerogel KY(P2S6)2 · K+ and the rare‐earth metal cations Y3+ connect [P2S6]2– anions to form an amorphous white gel. Supercritical drying of the resulting gel produced porous materials with a BET surface area of 443 m2 · g–1. The adsorption properties of the rare‐earth chalcophosphate aerogel were studied using volatile organic hydrocarbons (VOCs) and gases as adsorptives. The results showed preferential adsorption of toluene vapor over cyclohexane and cyclopentane vapor. The adsorption capacity toward toluene was 703 mg · g–1. Favored adsorption of CO2 over CH4, N2, or H2 was also observed for the aerogel: KY(P2S6)2 (CO2/H2: 308, CO2/CH4: 67, Co2/N2: 177). Pd doped aerogel showed significant enhancement toward toluene (1291 mg · g–1) for 1 wt % Pd @ KY(P2S6)2, (2064 mg · g–1) for 3 wt % Pd @ KY(P2S6)2 and (1108 mg · g–1) for 5 wt % Pd @ KY(P2S6)2. It also showed a noticeable improvement in the gas selectivity (CO2/H2: 337, CO2/CH4: 85, Co2/N2: 205) for 1 wt % Pd @ KY(P2S6)2, (CO2/H2: 345, CO2/CH4: 109, Co2/N2: 212) for 3 wt % Pd @ KY(P2S6)2 and (CO2/H2: 319, CO2/CH4: 73, Co2/N2: 187) for 5 wt % Pd @ KY(P2S6)2.  相似文献   

14.
Five different imidazolium‐based ionic liquids (ILs) were incorporated into a metal–organic framework (MOF), MIL‐53(Al), to investigate the effect of IL incorporation on the CO2 separation performance of MIL‐53(Al). CO2, CH4, and N2 adsorption isotherms of the IL/MIL‐53(Al) composites and pristine MIL‐53(Al) were measured to evaluate the effect of the ILs on the CO2/CH4 and CO2/N2 selectivities of the MOF. Of the composite materials that were tested, [BMIM][PF6]/MIL‐53(Al) exhibited the largest increase in CO2/CH4 selectivity, 2.8‐times higher than that of pristine MIL‐53(Al), whilst [BMIM][MeSO4]/MIL‐53(Al) exhibited the largest increase in CO2/N2 selectivity, 3.3‐times higher than that of pristine MIL‐53(Al). A comparison of the CO2 separation potentials of the IL/MOF composites showed that the [BMIM][BF4]‐ and [BMIM][PF6]‐incorporated MIL‐53(Al) composites both showed enhanced CO2/N2 and CO2/CH4 selectivities at pressures of 1–5 bar compared to composites of CuBTC and ZIF‐8 with the same ILs. These results demonstrate that MIL‐53(Al) is a versatile platform for IL/MOF composites and could help to guide the rational design of new composites for target gas‐separation applications.  相似文献   

15.
An innovative technique to obtain high‐surface‐area mesostructured carbon (2545 m2 g?1) with significant microporosity uses Teflon as the silica template removal agent. This method not only shortens synthesis time by combining silica removal and carbonization in a single step, but also assists in ultrafast removal of the template (in 10 min) with complete elimination of toxic HF usage. The obtained carbon material (JNC‐1) displays excellent CO2 capture ability (ca. 26.2 wt % at 0 °C under 0.88 bar CO2 pressure), which is twice that of CMK‐3 obtained by the HF etching method (13.0 wt %). JNC‐1 demonstrated higher H2 adsorption capacity (2.8 wt %) compared to CMK‐3 (1.2 wt %) at ?196 °C under 1.0 bar H2 pressure. The bimodal pore architecture of JNC‐1 led to superior supercapacitor performance, with a specific capacitance of 292 F g?1 and 182 F g?1 at a drain rate of 1 A g?1 and 50 A g?1, respectively, in 1 m H2SO4 compared to CMK‐3 and activated carbon.  相似文献   

16.
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   

17.
A novel metal‐doping strategy was developed for the construction of iron‐decorated microporous aromatic polymers with high small‐gas‐uptake capacities. Cost‐effective ferrocene‐functionalized microporous aromatic polymers (FMAPs) were constructed by a one‐step Friedel–Crafts reaction of ferrocene and s‐triazine monomers. The introduction of ferrocene endows the microporous polymers with a regular and homogenous dispersion of iron, which avoids the slow reunion that is usually encountered in previously reported metal‐doping procedures, permitting a strong interaction between the porous solid and guest gases. Compared to ferrocene‐free analogues, FMAP‐1, which has a moderate BET surface area, shows good gas‐adsorption capabilities for H2 (1.75 wt % at 77 K/1.0 bar), CH4 (5.5 wt % at 298 K/25.0 bar), and CO2 (16.9 wt % at 273 K/1.0 bar), as well as a remarkably high ideal adsorbed solution theory CO2/N2 selectivity (107 v/v at 273 K/(0–1.0) bar), and high isosteric heats of adsorption of H2 (16.9 kJ mol?1) and CO2 (41.6 kJ mol?1).  相似文献   

18.
The reaction of N‐rich pyrazinyl triazolyl carboxyl ligand 3‐(4‐carboxylbenzene)‐5‐(2‐pyrazinyl)‐1H‐1,2,4‐triazole (H2cbptz) with MnCl2 afforded 3D cationic metal–organic framework (MOF) [Mn2(Hcbptz)2(Cl)(H2O)]Cl ? DMF ? 0.5 CH3CN ( 1 ), which has an unusual (3,4)‐connected 3,4T1 topology and 1D channels composed of cavities. MOF 1 has a very polar framework that contains exposed metal sites, uncoordinated N atoms, narrow channels, and Cl? basic sites, which lead to not only high CO2 uptake, but also remarkably selective adsorption of CO2 over N2 and CH4 at 298–333 K. The multiple CO2‐philic sites were identified by grand canonical Monte Carlo simulations. Moreover, 1 shows excellent stability in natural air environment. These advantages make 1 a very promising candidate in post‐combustion CO2 capture, natural‐gas upgrading, and landfill gas‐purification processes.  相似文献   

19.
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   

20.
In metal–organic framework (MOF) chemistry, interpenetration greatly affects the gas‐sorption properties. However, there is a lack of a systematic study on how to control the interpenetration and whether the interpenetration enhances gas uptake capacities or not. Herein, we report an example of interpenetration that is simply controlled by the presence of a carbon–carbon double or single bond in identical organic building blocks, and provide a comparison of gas‐sorption properties for these similar frameworks, which differ only in their degree of interpenetration. Noninterpenetrated ( SNU‐70 ) and doubly interpenetrated ( SNU‐71 ) cubic nets were prepared by a solvothermal reaction of [Zn(NO3)2] ? 6 H2O in N,N‐diethylformamide (DEF) with 4‐(2‐carboxyvinyl)benzoic acid and 4‐(2‐carboxyethyl)benzoic acid, respectively. They have almost‐identical structures, but the noninterpenetrated framework has a much bigger pore size (ca. 9.0×9.0 Å) than the interpenetrated framework (ca. 2.5×2.5 Å). Activation of the MOFs by using supercritical CO2 gave SNU‐70′ and SNU‐71′ . The simulation of the PXRD pattern of SNU‐71′ indicates the rearrangement of the interpenetrated networks on guest removal, which increases pore size. SNU‐70′ has a Brunauer–Emmett–Teller (BET) surface area of 5290 m2 g?1, which is the highest value reported to date for a MOF with a cubic‐net structure, whereas SNU‐71′ has a BET surface area of 1770 m2 g?1. In general, noninterpenetrated SNU‐70′ exhibits much higher gas‐adsorption capacities than interpenetrated SNU‐71′ at high pressures, regardless of the temperature. However, at P<1 atm, the gas‐adsorption capacities for N2 at 77 K and CO2 at 195 K are higher for noninterpenetrated SNU‐70′ than for interpenetrated SNU‐71′ , but the capacities for H2 and CH4 are the opposite; SNU‐71′ has higher uptake capacities than SNU‐70′ due to the higher isosteric heat of gas adsorption that results from the smaller pores. In particular, SNU‐70′ has exceptionally high H2 and CO2 uptake capacities. By using a post‐synthetic method, the C?C double bond in SNU‐70 was quantitatively brominated at room temperature, and the MOF still showed very high porosity (BET surface area of 2285 m2 g?1).  相似文献   

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