Molecular Catalysis
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2018
·
IF 0
Fuhai Li,Dairong Hu,Yahui Yuan,Binbin Luo,Yibing Song,Songtao Xiao,Guanghui Chen,Yiwen Fang,Fushen Lu
To mimic biological enzyme in catalysis, metal-imidazole-salen complexes were proposed (via DFT calculation) and synthesized in situ within the cavities of Y zeolite. Among the synthesized zeozymes, the Cu-salenIIY exhibited a prominent catalytic efficiency for the selective oxidation of benzyl alcohol. Specifically, the activity and selectivity of the encapsulated catalyst were comparable to those of the free Cu-salenII complex in solution. Furthermore, the high activity and selectivity were preserved during the repeated cycles. The similarity in the initial activity implies that the Cu-salenII complex just resides in the cavity of the zeolite Y, and its intrinsic properties responsible for the catalytic activity keep intact after encapsulation. The confinement of zeolite nanocavities effectively inhibited the dimerization or aggregation of the Cu-salenII complex and prevented the active species from escaping into reaction solution, thus resulting in a remarkably improved in the catalytic reusability and durability.
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TALANTA
·
2018
·
IF 4.244
Xuemei Wang,Xiaomin Ma,Pengfei Huang,Juan Wang,Tongtong Du,Xinzhen Du,Xiaoquan Lu
Hybrid magnetic nanocomposites based on Cu-MOFs, graphene oxide (GO), and Fe 3 O 4 nanoparticles (NPs) were prepared via chemical bonding approach, which GO were used as platforms to load nanostructured Cu-MOFs and Fe 3 O 4 NPs. The composite features both magnetic separation characteristics and high MOFs porosity, making it an excellent adsorbent for magnetic solid-phase extraction (MSPE). The as-synthesized nanocomposites are characterized by XRD, TGA , SEM, TEM, nitrogen adsorption-desorption analysis and FT-IR spectroscopy. The composites are used in MSPE of six aromatic insecticides from various real samples prior to their quantification by HPLC . Amount of adsorbent, extraction times, extraction temperature, desorption times and oscillation rate are optimized. Under the optimal conditions, the method has a relative standard deviations (RSDs) of 1.9–2.7%, and good linearity (correlation coefficients higher than 0.9931). The low LOD and LOQ for six insecticides are found to be 0.30–1.58 μg L -1 and 1.0–5.2 μg L -1 , respectively. The RSDs of within batch extraction are 1.6–9.5% and 3.9–12% for batch to batch extraction. The experimental results suggest that the nanocomposites have potential application for removal of hazardous pollutants from effluents.
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PubMed
高影响因子
RARE METAL MATERIALS AND ENGINEERING
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2018
·
IF 0.29
Han Wensong
Cu-Ag particles with different molar ratios have been prepared in the hyperbranched polyester matrix using ascorbic acid as a reducing agent. The third generation hyperbranched polyester has been synthesized by step by step polymerization using the first generation hyperbranched polyester as core molecular and 2, 2-dimethylol propionic acid as branched monomer. The synthesized hyperbranched polyester and Cu-Ag alloy were characterized by FT-IR, 1 H-NMR, UV-vis spectra, X-ray diffraction (XRD), SEM, Energy Dispersive X-ray (EDX), Laser particle size measurement, TEM, etc. The XRD and EDX studies confirm the formation of Cu-Ag alloy. Laser particle size measurement, SEM and TEM studies show that the particles of the Cu-Ag alloy are well-dispersed with average size of 120 nm. The thermal properties of the Cu-Ag alloy have been studied by thermogravimetric Analysis (TGA). The results show that the measurement values are close to the theoretical ones.
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2018
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IF 2.88
Mao Xia Guo,Yuan Fang Li
Cu (II)-based metal-organic gels (Cu-MOGs), which are formed by 4-[2,2′:6′,2″-terpyridine]-4′-ylbenzoic acid (Hcptpy) and Cu (II) through ionic interactions, π-π stacking, van der Waals and hydrogen bonding , have been simply synthesized and used for the preparation of Cu (II)-based metal-organic xerogels (Cu-MOXs). Owing to the metal active sites in Cu-MOXs, Cu-MOXs were successfully applied to chromogenic experiment. The peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB), which could be catalyzed by Cu-MOXs from TMB to the oxidation state of TMB (oxTMB) and the color of TMB could be changed from colorless to blue with maximum absorbance at 657 nm, was selected as chromogenic agent. Thus, the Cu-MOXs-TMB-H 2 O 2 system based on MOXs was established. Due to the inhibitory effect of dopamine (DA) on oxidation process of TMB, the characteristic absorption peak intensity of oxTMB decreased when the DA was added into the mixed solution. Subsequently, the Cu-MOXs-TMB- H 2 O 2 system was used for DA detection. The linear range for DA was 0.5 μM–20 μM and the detection limit was 85.76 nM. Our work has helped to develop the promising application of Cu-MOGs material in the field of nanozymes property.
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高影响因子
RSC Advances
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2018
·Vol. 8
·期 59
·34151-34160
·
IF 2.936
Changjiang Yu,Dashuai Zhang,Xinyu Dong,Qiang Lin
The reduction behavior of Fe3+ during the preparation of a zero-valent iron cocoanut biochar (ZBC8-3) by the carbothermic reduction method was analyzed. Fe3+ was first converted into Fe3O4, which was subsequently decomposed into FeO, and finally reduced to Fe0. A minor amount of γ-Fe2O3 was produced in the process. The isothermal thermodynamic data for the removal of Cu(II) over ZBC8-3 followed a Langmuir model. The Langmuir equation revealed a maximum removal capacity of 169.49 mg g−1 at pH = 5 for ZBC8-3. The removal of Cu(II) over ZBC8-3 fitted well to a pseudo-first-order equation, which suggested that the rate limiting step of the process was diffusion. The Cu(II) removal mechanism on ZBC8-3 involved the reduction of Cu(II) by Fe0 to produce Cu0 and Cu2O, while CC, C–O–, and –O–H formed a complex with Cu(II).
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高影响因子
RSC Advances
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2019
·Vol. 9
·期 27
·15642-15647
·
IF 3.049
Fuping Tian,Chenxia Qiao,Renyu Zheng,Qiaofeng Ru,Xin Sun,Yifu Zhang,Changgong Meng
A bimetallic–organic porous material (Cu/Co-BTC) with a paddle-wheel structure has been successfully synthesized by a solvothermal approach. The as-synthesized materials were characterized by XRD, SEM, ICP-AES, UV-Vis, TGA and N2 adsorption at 77 K. The prepared Cu/Co-BTC samples were investigated in thiophene (TP) adsorption from model gasolines by the fixed bed adsorption method at 298 K. The results showed that only a small amount of Co could be successfully introduced into the framework of HKUST-1, and the introduction of Co had little effect on the crystalline structure, morphology, porosity, and thermal stability. The bimetallic Cu/Co-BTC with a Cu/Co ratio of 174 displayed significantly improved adsorption desulfurization performance, showing an increase in breakthrough volume by 30% compared with HKUST-1, implying that the central metal in the MOF plays an important role in adsorption desulfurization. The addition of toluene or cyclohexene (3.20–3.30 vol%) as a competitor in the model gasoline led to a decline in desulfurization performance, especially when cyclohexene was added. The bimetallic Cu/Co-BTC showed a slight loss in breakthrough volume by only 5% after regenerating 7 times, displaying an excellent regeneration property.
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高影响因子
Inorganic Chemistry Frontiers
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2019
·Vol. 6
·期 7
·1799-1812
·
IF 5.934
Xiaosong Hu,Chaoyue Zhao,Qingxin Guan,Xin Hu,Wei Li,Jun Chen
The chemical transformation of CO2 not only mitigates CO2 released into the atmosphere but also produces fuels and chemicals with important additional value. The activation of stable CO2 molecules is the key difficulty for the efficient conversion of CO2. Herein, we designed a ternary catalyst containing Cu, ZnO, and CeOx and dispersed them in SBA-15 using incipient wetness impregnation. Interestingly, the catalytic performances were improved greatly when the related active components were dispersed inside and outside the pore channels of SBA-15 using the incipient wetness impregnation method. Methanol and CO were controllably produced on the interface of Cu and metal oxides (ZnO and CeOx) due to the synergistic effects between the three active components. The metal oxides play a more important role in CO2 conversion as well as the product selectivity compared to Cu. CeO2 is more efficient than ZnO in promoting the dispersion of Cu nanoparticles and methanol generation. The suitable pore channels of SBA-15 promote the mass transfer and heat transfer while the high specific surface area is favorable to the dispersion of active components, which will facilitate the production of methanol and CO. After continuous hydrogenation evaluation for 100 h, the catalytic performance of the catalyst was still very stable. This work provides a viable strategy to prepare a supported catalyst with highly dispersed active sites, and the catalyst exhibits an efficient catalytic effect on producing methanol and CO.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Honghua Zhang,Jiakuo Xu,Hongguo Tang,Zhiqiang Yang,Ruixia Liu,Suojiang Zhang
Different metal compositions based on metal-ion-modified X-type zeolite in the isobutane/2-butene alkylation reaction were investigated. Bimetallic (rare earth (RE) and Cu) supported zeolites catalysts owned better lifetime and selectivity than those modified by the single metal (La, Ce, or Cu). CuLaX performed best with a 15 h catalytic lifetime obtained after hydrogen activation when the content of copper was 0.197 mmol/g. The possible reason is that the RE X-type catalyst modified with copper ion increases the concentration of strong Brønsted acid sites, which is more favorable for the hydride transfer in the alkylation. Herein, the valence of copper ions is of importance to the alkylation performance. A mechanism was proposed wherein the existence of Cu+ inhibited the progress of the oligomerization reaction and then prolonged the lifetime of the catalyst through decreasing the desorption concentration of 2-butene in the active site.
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高影响因子
Frontiers of Environmental Science & Engineering
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2018
·Vol. 12
·期 6
·1-10
·
IF 1.961
Mao Jie,Quan Xie,Wang Jing,Gao Cong,Chen Shuo,Yu Hongtao,Zhang Yaobin
Heterogeneous Fenton-like reaction has been extensively investigated to eliminate refractory organic contaminants in wastewater, but it usually shows low catalytic performance due to difficulty in reduction from Fe(III) to Fe(II). In this study, enhanced catalytic efficiency was obtained by employing Cu-doped BiFeO 3 as heterogeneous Fenton-like catalysts, which exhibited higher catalytic performance toward the activation of H 2 O 2 for phenol degradation than un-doped BiFeO 3 . BiFe 0.8 Cu 0.2 O 3 displayed the best performance, which yielded 91% removal of phenol (10 mg L –1 ) in 120 min. The pseudo first-order kinetic rate constant of phenol degradation in BiFe 0.8 Cu 0.2 O 3 catalyzed heterogeneous Fenton-like reaction was 5 times higher than those of traditional heterogeneous Fenton-like catalysts, such as Fe 3 O 4 and goethite. The phenol degradation efficiency could still reach 83% after 4 cycles, which implied the good stability of BiFe 0.8 Cu 0.2 O 3 . The high catalytic activity of BiFe 0.8 Cu 0.2 O 3 was attributed to the fact that the doping Cu into BiFeO 3 could promote the generation of Fe(II) in the catalyst and then facilitate the activation of H 2 O 2 to degrade the organic pollutants.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2017
·
IF 6.065
Weirui Chen,Xukai Li,Yiming Tang,Jialu Zhou,Dan Wu,Yin Wu,Laisheng Li
A flexible catalyst, Fe-Cu-MCM-41, was employed to enhance diclofenac (DCF) mineralization and inhibit bromate formation in catalytic ozonation process. Greater TOC removal was achieved in Fe-Cu-MCM-41/O 3 process (78%) than those in Fe-MCM-41/O 3 (65%), Cu-MCM-41/O 3 (73%) and sole ozonation (42%). But it was interesting that both Cu-MCM-41/O 3 and Fe-MCM-41/O 3 achieved 93% bromate inhibition efficiency, only 71% inhibition efficiency was observed in Fe-Cu-MCM-41/O 3 . Influence of pH, TBA/NaHSO 3 and detection of by-products were conducted to explore the mechanism. By Pyridine adsorption–IR and XPS, a relationship was found among activity of catalysts, Lewis acid sites and electron transfer effect between Fe (II/III) and Cu (I/II). Fe-Cu-MCM-41 promoted ozone decomposition to generate OH, which accounted for enhanced DCF mineralization. The consumption of aqueous O 3 also suppressed the oxidative of Br − and HBrO/Br − . More HBrO/BrO − accumulated in catalytic ozonation process and less bromate generated. Bromate formation in Fe-Cu-MCM-41/O 3 process was sensitive with pH value, the acidic condition was not favor for bromate formation. Both DCF mineralization and bromate inhibition were influenced by surface reaction. Moreover, Fe-Cu-MCM-41 showed excellent catalytic performance in suppressing the accumulation of carboxylic acid, especially for oxalic acid. Nearly no oxalic acid was detected during Fe-Cu-MCM-41/O 3 process.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2017
·
IF 5.401
Shuang Li,Te Wei,Mingyu Tang,Fang Chai,Fengyu Qu,Chungang Wang
Here, we reported on a route to the facile synthesis of bimetallic silver doped copper nanoparticles (Ag-Cu NPs) by AgNO 3 and CuSO 4 in the presence of sodium borohydride and sodium citrate. The present work described the preparation of the Ag-Cu NPs with sodium citrate and the use of them in colorimetric detection of mercury (II) ions. Ag-Cu NPs with an average diameter of 9.0 ± 0.8 nm were prepared via two step reduction at room temperature. The Ag-Cu NPs were thoroughly characterized by using UV–vis spectroscopy and transmission electron microscopy (TEM) techniques. The morphology and constitution of the Ag-Cu NPs were characterized by TEM, and the valence state of Ag-Cu NPs was confirmed by the X-ray photoelectron spectroscopic (XPS) result. The synthesized Ag-Cu NPs were yellow in color due to the intense surface plasmon absorption band centered at 406 nm. This high selective sensor allowed a direct quantitative assay of mercury ions (Hg 2+ ) with a detection limited of 0.51 nM. The synthesized Ag-Cu NPs also exhibited good catalytic activity in two model reactions, the reduction of the nitrophenols and potassium ferricyanide (III) by sodium borohydride.
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AICHE JOURNAL
·
2017
·Vol. 64
·期 2
·538-549
·
IF 2.836
Yiyi Sheng,Yang Sun,Jing Xu,Jie Zhang,Yi-Fan Han
Cu-embedded mesoporous alumina, as a Fenton-like catalyst prepared via a sol-gel method, showed excellent activity and durability for the degradation of refectory compounds. The origin of active sites for the generation of hydroxyl radicals (•OH) were thoroughly studied using multitechniques. Cu, as the only active element, could be penetrated into the bulk of alumina and some Cu atoms were embedded into the framework. The dynamic structure of surface Cu species (the variety of Cu + /Cu 2+ ratio) during the reaction were determined as well. Furthermore, the structure plasticity of catalyst has proved by optimizing preparation and reaction conditions. A 98.53% degradation of RhB was recorded within 30 min, following a pseudo-first-order reaction rate expression. Electron spin resonance spectra and •OH scavenging experiments have confirmed that •OH is the main reactive oxidant for the elimination of RhB. By the surface-enhanced Raman spectroscopy and gas chromatography-mass spectrometer results, plausible pathways of RhB degradation were elaborated. © 2017 American Institute of Chemical Engineers AIChE J , 64: 538–549, 2018
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