JOURNAL OF PHYSICS D-APPLIED PHYSICS
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2017
·Vol. 50
·期 47
·475202
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IF 2.588
Junliang Wu,Qibin Xia,Jing Xiao,Zhong Li
Catalytic performance of MIL-101—a type of chromium-based metal-organic frameworks (MOFs)—in a plasma catalysis system for toluene removal was experimentally studied. The MIL-101 was synthesized using a hydrothermal method, and its catalytic performance was compared to two other catalysts, Cr2O3/γ-Al2O3 and γ-Al2O3, in a dielectric barrier discharge (DBD) reactor. Results showed that the presence of a catalyst in plasma changed the voltage and current characteristic substantially, and promoted the performance of the plasma reactor. Among the catalysts, the MIL-101 exhibited a significantly high toluene conversion, which was 20% and 35% higher than Cr2O3/γ-Al2O3 and γ-Al2O3, respectively, under the same testing conditions, as well as higher carbon balance and CO2 selectivity. The analysis of by-products on the surfaces of the catalysts before and after reaction demonstrated that MIL-101 had better resistance towards by-products accumulation compared to Cr2O3/γ-Al2O3 and γ-Al2O3. The loading of MnOx on MIL-101 further promoted its catalytic performance. MIL-101 exhibits attractive catalytic properties as a catalyst in a plasma catalysis system for the decomposition of volatile organic compounds.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
ENERGY & FUELS
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2017
·
IF 3.091
Xuejiao Sun,Daofei Lv,Yongwei Chen,Ying Wu,Qihui Wu,Qibin Xia,Zhong Li
Chromium-based MIL-101 and graphite oxide (GO) composite (MIL-101@GO) was synthesized and applied for adsorption performances toward a series of aromatics (benzene, toluene, and ethylbenzene). Desorption activation energies of aromatics on this composite were evaluated based on temperature-programmed desorption (TPD) experiments. The results indicated that the aromatic uptakes on the composite increase with the carbon number at low pressure. In contrast, at high pressure, their adsorption capacities exhibit an opposite trend. The composite possesses high uptakes of the aromatics, which are approximately 1.8–6.0 times higher compared with conventional adsorbents. The desorption activation energies of the aromatics increase with the carbon number of aromatics. Additionally, the adsorption of ethylbenzene on the composite is highly reversible. More importantly, the MIL-101@GO composite exhibits enhanced thermal conductivity up to 0.369 W/mK at 303 K. The MIL-101@GO composite with high adsorption capacity, enhanced thermal conductivity, and efficient recyclability provided a promising candidate for practical applications in field of volatile organic compounds adsorption.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Journal of Energy Storage
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2022
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IF 8.907
Xiutao Li,Feng Zhang,Mengjie Zhang,Zhenyang Zhou,Xiaomeng Zhou
To improve the electrochemical performance and safety of the traditional polymer separator, two kinds of chromium-based MOFs (Cr-MOFs) (namely MIL-88B(Cr) and MIL-101(Cr)) were studied as separator coatings. Compared with inorganic coating (Al 2 O 3 ), Cr-MOFs coated separators exhibited improved thermal stability, better flame retardance, superior electrolyte wettability, high electrolyte uptake, good ionic conductivity and enhanced electrochemical performance. Moreover, although MIL-88B(Cr) and MIL-101(Cr) have the same metal center (Cr 3+ ) and organic ligand (1,4-benzene dicarboxylate), their improvements on the performance of coated separators are obvious different. The detailed analyses reveal that the specific surface area, pore size and structure stability of Cr-MOFs are the main factors that affect their performances. The result of this work provides an essential basis for developing high performance separators with MOFs.
研究领域:
材料科学
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电化学
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产品关联
DOI
高影响因子
DIAMOND AND RELATED MATERIALS
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2020
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IF 2.65
Qi Zhao,Qian Lei,Xueping Gan,Long Zhang,Kechao Zhou
Poor interfacial adhesion and the aggregation of carbon nanotubes (CNTs) are important factors that restrict effective synthesis in CNTs-reinforced copper matrix composites (CMCs). Here, chemical unzipping and matrix-alloying (addition of Cr) methods were integrated to address these two limitations of CMCs. The CuCr matrix composite reinforced with partially-unzipped CNTs (PUCNTs) was manufactured using flake powder metallurgy and spark plasma sintering (SPS) processes. The effects of PUCNTs on microstructure, microhardness , electrical conductivity , and tribological properties of the composites were studied. The results showed that the in-situ interfacial carbides (Cr 7 C 3 or Cr 23 C 6 ) improved interfacial adhesion between PUCNTs and CuCr matrix. Additionally, the microhardness and tribological performances of PUCNTs/CuCr composites were obviously improved with increased concentrations of PUCNTs. When the PUCNTs content reached 8 vol%, the microhardness of the PUCNTs/CuCr composite was about 116% and 63% higher than that of unreinforced CuCr and CNTs/CuCr composite, respectively. The coefficient of friction and wear rate of the PUCNTs/CuCr composite were about 70% and 68% lower, respectively, than those of unreinforced CuCr. A balance was obtained between the electrical conductivity and tribological properties of the PUCNTs/CuCr composite. The results of this study show PUCNTs are better reinforcement fillers than CNTs, and suggest a new strategy for the fabrication of sliding electrical contact composites with high performance.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
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IF 10.652
Yutong Zhao,Dingkai Chen,Jiangping Liu,Dedong He,Xiaohua Cao,Caiyun Han,Jichang Lu,Yongming Luo
Chromium (Cr) species with different loading (1, 2.5, 5, 7.5 and 10 wt%) were impregnated over alumina (Al 2 O 3 ) and silica (SiO 2 ) supports to investigate the effects of the metal-support interactions on decomposing methyl mercaptan. The characterization results revealed that the amount and nature of surface hydroxyl groups of support (Al-OH and Si-OH) induce the different interactions between chromium species and support, which generates an exceeding support-dependent dispersion, oxidation states, reducibility, and acid-base properties for the prepared Cr-based catalysts. As compared with SiO 2 support, Al 2 O 3 -supported chromium catalysts with evenly dispersed monochromatic Cr(VI) species exhibited excellent catalytic activity by means of theirs enhanced reducibility and sufficient acid-basic sites. Therefore, it is concluded that the metal-support interactions can be tailored by engineering the amount and nature of hydroxyl groups on the support.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2014
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IF 3.674
Siyang Tang,Zhen Liu,Xiaowei Yan,Ning Li,Ruihua Cheng,Xuelian He,Boping Liu
An extensive experimental kinetic study of ethylene trimerization was carried out over the Chevron-Phillips homogeneous catalyst system [Cr(2-ethylhexanoate) 3 (Cr(2-EH) 3 )/2,5-dimethylpyrrole (DMP)/co-catalyst/halide] in terms of the effects from organic halide additives, type of co-catalysts, temperature, ethylene pressure, Cr concentration, and ligand/Cr molar ratio, etc. Ten kinds of organic halides and four kinds of organometallic co-catalysts were tested in this work. The 1,1,2,2-tetrachloroethane (TCE) and triethylaluminum (TEA) were found to be the best candidates for this catalyst system. The molar ratios of DMP/Cr, TCE/Cr and TEA/Cr showed a strong impact on the catalytic performance of ethylene trimerization. A detailed catalytic kinetic behavior and the kinetic simulation were also performed for the first time over this catalyst system. It could be extrapolated that the dependency of the trimerization reaction rate on ethylene concentration and catalyst concentration is second-order and first-order, respectively. The apparent activation energy of this reaction is 99.1 kJ/mol at the temperature range from 65 °C to 95 °C. And the apparent reaction rate equation is achieved as follows:. R = 5.23 × 10 18 exp − 99.1 R T C ca 1.12 C e 1.95 .
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Zhuan-nian Liu,A.-ping Fan,Xiao-gang Han,Habiba Shapour,Qing-yun Zhang
The chelating adsorbent PEI-MIL-101(Cr) was prepared by introducing polyethyleneimine (PEI) into the MIL-101(Cr) channel in this paper. X-ray diffractometer, Fourier transform infrared spectrometer and scanning electron microscope were applied to characterize the structure and morphology of MIL-101(Cr) and PEI-MIL-101(Cr). The adsorption properties and mechanism of the MIL-101(Cr) and PEI-MIL-101(Cr) to Cr(VI) were studied. The results showed that adsorption capacity of PEI-MIL-101(Cr) for Cr(VI) was obviously better than MIL-101(Cr). The adsorption isotherm of Cr(VI) onto MIL-101(Cr) and PEI-MIL-101(Cr) can be described by Langmuir model. The maximum adsorption amount for Cr(VI) onto MIL-101(Cr) and 30% PEI-MIL-101(Cr) was 61.99 and 40.34 mg/g. The adsorption kinetic data of the two adsorbents followed the pseudo second-order model. The negative values ΔH and ΔG illustrate that the process is spontaneous and exothermic. PEI-MIL-101(Cr) can be reused for four times.
研究领域:
环境化学
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材料科学
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污染控制
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吸附技术
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功能材料
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水污染治理
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DOI
高影响因子
CARBON
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2018
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IF 7.082
Yuanyuan Zhang,Peng Yan,Qijin Wan,Nianjun Yang
Metal-organic frameworks (MOFs) are attractive materials for electrochemical applications because of their large surface areas and rich pore structures . However, their poor electrical conductivity hinders these applications. In this contribution, the decoration of chromium terephthalate MOFs (MIL-101(Cr) crystals) with reduced graphene oxide (rGO) is proposed to improve the electrical conductivity of MIL-101(Cr) crystals. These nanocomposites (MIL-101(Cr)@rGO) were prepared using a simple chemical reduction method. Their morphology, interfacial properties , and electrochemical applications were investigated using electron microscopy , electrochemical, and related techniques. With an introduction of rGO into MIL-101(Cr) crystals, the conductivity of MIL-101(Cr)@rGO nanocomposites was much improved. As a case study of electrochemical applications of MIL-101(Cr)@rGO nanocomposites, the MIL-101(Cr)@rGO nanocomposite coated electrodes were employed for the voltammetric study of 4-nonylphenol. An irreversible, adsorption-controlled, one electron and one proton involved oxidation process was observed. By use of the recorded anodic peak current as the physical parameter, the sensitive and reproducible monitoring of 4-nonylphenol was realized in the range of 0.1–12.5 μM with a detection limit of 33 nM. The MIL-101(Cr)@rGO nanocomposites are thus useful electrode materials . The proposed strategy provides a simple and efficient approach to expand easily the applications of MOFs into various electrochemical fields.
研究领域:
材料科学
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环境科学
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电化学
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DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2025
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IF 3.5
Shuaikun Li,Yanhong Wang,Haibo Li,Hang Liu,Yun Lv,Hongcheng Lu
A novel magnetic alkaline-earth chromium fluoroiodate Ba 2 CrIO 3 F 6 has been successfully synthesized via the hydrothermal method and characterized for its structure and physical properties by single crystal X-ray diffraction, attenuated total reflection (ATR) infrared spectroscopy, UV-vis-NIR spectroscopy, thermal stability, as well as magnetic susceptibility, and specific heat. The compound Ba 2 CrIO 3 F 6 contains the [CrIO 3 F 6 ] 4- spin chains which are further separated by nonmagnetic Ba 2+ cations. The magnetic susceptibility results show no long-range magnetic order down to 2 K, which are further confirmed by specific heat measurement. The positive Weiss temperature and the increase of χT - T curve at low temperature both suggest the magnetic exchange interactions through the Cr 3+ −IO 4 F−Cr 3+ pathway are unexpectedly ferromagnetic. Our work illustrates that it is promising to use the IO x F y anion group for the design and construction of novel magnetic materials with ferromagnetic exchange interactions for potential spintronics device applications.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Zhao Sun,Ke Li,Sam Toan,Rongjun Zhang,Hongwei Li,Yu Wu,Zhiqiang Sun
Redox nitrogen fixation-nitride hydrolysis looping provides a promising pathway for ammonia synthesis; however, high N fixation temperature and low N 3− lattice supplement efficiency limit its further development and application. In this regard, a two-step chemical looping ammonia synthesis route, chromium-based nitrogen carrier enabled low-temperature N fixation and nitrogen carrier hydrolysis, is proposed to intensify ammonia generation. In the N fixation step, the effects of carbon species on the carbothermal reduction performance are investigated. Results reveal that decreasing the graphitization degree of the carbon species can effectively reduce the nitrogen activation temperature from 1054 °C to 948 °C. Meanwhile, the C/Cr 2 O 3 ratio required is correlated with the amount of oxygen in carbon species, and the appropriate active carbon/biochar-to-Cr ratios are 4.00 and 3.25, respectively. In the ammonia synthesis step, the nitrogen carrier hydrolysis rate is mainly limited by the diffusion of reactive species. The ammonia formation rate reaches 0.127 mmol·h −1 ·g −1 nitrogen carrier at 1100 °C. XRD retrieve refinement results reveal that the utilization of the lattice nitrogen decreases with the increase in the ammonia releasing temperature. This study provides new implications for advanced nitrogen carrier exploitation, which will substantially promote the development of chemical looping ammonia synthesis technologies with lowered energy consumption.
研究领域:
化学工程
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催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
NATURE
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2024
·Vol. 632
·期 8027
·1032-1037
·
IF 50.5
Liu Yi,Liu Zi-Yi,Bao Jin-Ke,Yang Peng-Tao,Ji Liang-Wen,Wu Si-Qi,Shen Qin-Xin,Luo Jun,Yang Jie,Liu Ji-Yong,Xu Chen-Chao,Yang Wu-Zhang,Chai Wan-Li,Lu Jia-Yi,Liu Chang-Chao,Wang Bo-Sen,Jiang Hao,Tao Qian,Ren Zhi,Xu Xiao-Feng,Cao Chao,Xu Zhu-An,Zhou Rui,Cheng Jin-Guang,Cao Guang-Han
Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1 , 2 , 3 , 4 , 5 ), yet the experimental realization is hard to achieve 6 , 7 . The recently discovered vanadium-based kagome materials 8 , which exhibit both superconductivity 9 , 10 , 11 and charge-density-wave orders 12 , 13 , 14 , are nonmagnetic 8 , 9 and weakly correlated 15 , 16 . Thus these materials are unlikely to host the exotic superconductivity theoretically proposed. Here we report the discovery of a chromium-based kagome metal, CsCr 3 Sb 5 , which is contrastingly featured with strong electron correlations, frustrated magnetism and characteristic flat bands close to the Fermi level. Under ambient pressure, this kagome metal undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4 a 0 structural modulation. At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with pressure and, remarkably, a superconducting dome emerges at 3.65–8.0 GPa. The maximum of the superconducting transition temperature, T c max = 6.4 K, appears when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behaviour, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors 17 , 18 . Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems.
研究领域:
凝聚态物理
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强关联电子系统
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超导物理
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量子材料
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DOI
高影响因子
危险品化学品经营许可证（带存储）