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1.
采用简单易行的浸渍法将Pt纳米粒子负载到MIL-101(Cr)上, 制备了Pt/MIL-101(Cr)催化剂, 并对其在肉桂醛选择性加氢反应的催化性能进行了研究。XRD、N2吸附、TEM和催化性能的研究结果表明, Pt的负载量对负载于MIL-101(Cr)上Pt纳米粒子的尺寸及所制备催化剂对肉桂醇的选择性有很大影响。低Pt负载量(1.0wt%)的Pt/MIL-101(Cr)较其他MOFs和无机材料在肉桂醛选择性加氢反应中表现出了高的催化性能, 在优化的反应条件下肉桂醛转化率和对肉桂醇的选择性可分别达96.5%和86.2%。Pt/MIL-101(Cr)催化剂具有良好的稳定性。Pt/MIL-101(Cr)所表现出的优良的催化性能同MIL-101(Cr)载体的孔道结构及其表面性质密切相关。  相似文献
2.
采用简单易行的浸渍法将Pt纳米粒子负载到MIL-101(Cr)上,制备了Pt/MIL-101(Cr)催化剂,并对其在肉桂醛选择性加氢反应的催化性能进行了研究。XRD、N2吸附、TEM和催化性能的研究结果表明,Pt的负载量对负载于MIL-101(Cr)上Pt纳米粒子的尺寸及所制备催化剂对肉桂醇的选择性有很大影响。低Pt负载量(1.0%)的Pt/MIL-101(Cr)较其他MOFs和无机材料在肉桂醛选择性加氢反应中表现出了高的催化性能,在优化的反应条件下肉桂醛转化率和对肉桂醇的选择性可分别达96.5%和86.2%。Pt/MIL-101(Cr)催化剂具有良好的稳定性。Pt/MIL-101(Cr)所表现出的优良的催化性能同MIL-101(Cr)载体的孔道结构及其表面性质密切相关。  相似文献
3.
Metal-organic frameworks (MOFs) have received great attention as novel sorbents due to their fascinating structures and intriguing potential applications in various fields. In this work, a MIL-101(Cr)-coated solid-phase microextraction (SPME) fiber was fabricated by a simple direct coating method and applied to the determination of volatile compounds (BTEX, benzene, toluene, ethylbenzene, m-xylene and o-xylene) and semi-volatile compounds (PAHs, polycyclic aromatic hydrocarbons) from water samples. The extraction and desorption conditions of headspace SPME (HS-SPME) were optimized. Under the optimized conditions, the established methods exhibited excellent extraction performance. Good precision (<7.7%) and low detection limits (0.32–1.7 ng L−1 and 0.12–2.1 ng L−1 for BTEX and PAHs, respectively) were achieved. In addition, the MIL-101(Cr)-coated fiber possessed good thermal stability, and the fiber can be reused over 150 times. The fiber was successfully applied to the analysis of BTEX and PAHs in river water by coupling with gas chromatography–mass spectrometry (GC–MS). The analytes at low concentrations (1.7 and 10 ng L−1) were detected, and the recoveries obtained with the spiked river water samples were in the range of 80.0–113% and 84.8–106% for BTEX and PAHs, respectively, which demonstrated the applicability of the self-made fiber.  相似文献
4.
A heterogeneous catalyst was synthesized by encapsulation of a Keggin‐type heteropolytungstate, potassium dodecatungstocobaltate trihydrate, K5[CoW12O40]·(Co‐POM), into chromium(III) terephthalate (MIL‐101). Encapsulation was achieved via a ‘build bottle around ship’ strategy in aqueous media, following a hydrothermal method. The structure of the resulting crystalline solid was characterized using X‐ray diffraction, correlated with Fourier transform infrared and UV–visible spectroscopy. The metal content was analysed using optical emission spectroscopy. Transmission electron microscopy was used to measure particle size and N2 adsorption in a Brunauer–Emmett–Teller instrument to characterize the specific surface area. The catalytic activity was investigated using methanolysis of epoxides under mild conditions as a test reaction. The turnover frequency of the heterogeneous Co‐POM@MIL‐101 catalyst was more than 20 times higher than that of the homogeneous Co‐POM catalyst. The Co‐POM@MIL‐101 catalyst was reused several times with negligible leaching of Co‐POM and with no considerable loss of its initial efficiency. The simplicity of preparation, extraordinary stability and high reactivity make Co‐POM@MIL‐101 an exceptional catalytic matrix that is easily separable from reaction media.  相似文献
5.
Ethylene diamine functionalized MIL‐101(Cr) was established to be an efficient organocatalyst for single‐pot synthesis of polyhydroquinolines via four‐component condensation reaction between aldehydes, dimedone, β‐ketoecters and ammonium acetate in aqueous medium. Ethylene diamine of the parent open metal site MIL‐101(Cr) has been carried out through a post‐synthetic modification (PSM) technique. Efficient transformation, mild condition, easy product isolation and the potential high recycbility of the organocatalyst are the key feature of this protocol.  相似文献
6.
A series of novel metal-organic framework-anchored RuCl3 catalysts for the CO2 hydrogenation to formic acid have been developed. RuCl3@MIL-101(Cr)-DPPB catalyst exhibited the higher catalytic performance for hydrogenation of CO2 to formic acid due to the phosphorus atom of DPPBde as a stronger electron-donor substituent to promote the insertion of CO2 into RuH bond.  相似文献
7.
The tandem oxidative three-component synthesis of two types of the heterocycles such as furans and imidazopyridines, via isocyanides [1+4] cycloaddition reactions in the presence of MIL-101(Cr) under aerobic conditions are reported. When the 4-toluenesulfonylmethyl isocyanide was used, an unexpected [3+2] cycloaddition reaction of isocyanides with aldehydes accomplished and dihydrophenyloxazoles and phenyloxazoles produced. These syntheses were successfully carried out using a wide scope of the substrates.  相似文献
8.
The catalytic activity of 5,10,15,20‐tetrakis(4‐aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [SnIV(TNH2PP)(OTf)2], supported on chloromethylated MIL‐101, was investigated in the trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) and also their tetrahydropyranylation with 3,4‐dihydro‐2H‐pyran. Excellent yields, mild reaction conditions, short reaction times and reusability of the catalyst without significant decrease in its initial activity are noteworthy advantages of this supported catalyst. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献
9.
Excessive consumption of Fe (II) and massive generation of sludge containing Fe (III) from classic Fenton process remains a major obstacle for its poor recycling of Fe (III) to Fe (II). Therefore, the MHACF‐MIL‐101(Cr) system, by introducing H2, Pd0 and MIL‐101(Cr) into Fenton reaction system, was developed at normal temperature and pressure. In this system, the reduction of FeIII back to FeII by solid catalyst Pd/MIL‐101(Cr) for the storage and activation of H2, was accelerated significantly by above 10‐fold and 5‐fold controlled with the H2‐MIL‐101(Cr) system and H2‐Pd0 system, respectively. However, the concentration of Fe (II) generated by the reduction of Fe (III) could not be detected with the only input of H2 and without the addition of MOFs material. In addition, the apparent consumption of Fe (II) in MHACF‐MIL‐101(Cr) system was half of that in classical Fenton system, while more Fe (II) might be reused infinitely in fact. Accordingly, only trace amount of Fe (II) vs H2O2 concentration was needed and hydroxyl radicals through the detection of para‐hydroxybenzoic acid (p‐HBA) as the oxidative product of benzoic acid (BA) by·OH could be continuously generated for the effective degradation of 4‐chlorophenol(4‐CP). The effects of initial pH, concentration of 4‐CP, dosage of Fe2+, H2O2 and Pd/MIL‐101(Cr) catalyst, Pd content and H2 flow were investigated, combined with systematic controlled experiments. Moreover, the robustness and morphology change of Pd/MIL‐101(Cr) were thoroughly analyzed. This study enables better understanding of the H2‐mediated Fenton reaction enhanced by Pd/MIL‐101(Cr) and thus, will shed new light on how to accelerate Fe (III)/Fe (II) redox cycle and develop more efficient Fenton system.  相似文献
10.
ABSTRACT

A simple, one-pot procedure for the synthesis of novel 3-phenyl-3,4-dihydro-2H-benzo[a][1,3] oxazino[5,6-c]phenazine derivatives by four-component coupling reaction between benzo[a]phenazine-5-ol, formaldehyde and amine in the presence of a catalytic amount ZnO-PTA@Fe3O4/EN-MIL-101(Cr) nanopowder in ethanol at room temperature under stirring condition. ZnO-PTA@Fe3O4/EN-MIL-101(Cr) An inorganic magnetic catalyst was analyzes and described by the XRD, TEM, FESEM, TGA, AFM, VSM and ICP-OES. This study presents simple, efficient, and one-pot multicomponent protocol, which provides several advantages such as short reaction times, high yields, easy working up, chromatography-free technique, catalyst recovery, and reusability are other highlights of this work.  相似文献
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