FUEL
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2018
·
IF 4.908
Yun-Chuan Pu,Shui-Rong Li,Shuai Yan,Xiao Huang,Duo Wang,Yue-Yuan Ye,Yun-Quan Liu
Copper sintering at temperatures above 200 °C has been a big challenge for the application of copper-based catalysts in methanol reforming for hydrogen production. In the present work, a Cu/ZnO catalyst promoted by Sc 2 O 3 was developed, which is capable of converting methanol into hydrogen-rich gas with good activity and decent stability in the temperature range of 220–600 °C. The role of Sc in Cu/Sc 2 O 3 -ZnO catalysts was explored through the XRD, H 2 -TPR, N 2 O chemisorption, TEM, Raman, and XPS analyses. The results indicated that ZnO lattice was doped with the Sc 3+ ion, which led to increased metal dispersion, strengthened interaction between Cu metal and support oxide, and subsequently enhanced catalytic activity and stability of the Cu/Sc 2 O 3 -ZnO catalyst in methanol reforming for hydrogen production.
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高影响因子
ChemCatChem
·
2018
·Vol. 10
·期 18
·4010-4017
·
IF 4.674
Kui Ma,Zhonghui Cui,Zhitao Zhang,Jingjing Huang,Zhirui Sun,Ye Tian,Tong Ding,Xingang Li
Graphical Blowing off steam : This paper describes a new approach of designing Cu−Ni bimetallic catalytic systems for dimethyl ether/methanol steam reforming. The Cu−Ni system exhibits an interesting alloy-mediated selectivity of CO and CH 4 , thereby producing hydrogen-rich reformates with an ultra-low CO concentration (<1000 ppm), which could be commercially potential for fuel cells. Steam reforming of simple oxygenated hydrocarbons without C−C bonds is suitable for small-scale decentralized H 2 production for fuel cells. However, the relatively high CO concentration in H 2 -rich reformates produced by traditional Cu-based catalysts will poison the Pt-based anode in fuel cells. Here, we describe a new approach to the design of Cu−Ni bimetallic catalysts based on nickel-phyllosilicate for steam reforming of dimethyl ether (DME). With the tunable formation of the Cu−Ni alloy, we can modulate the selectivity of CO and CH 4 in steam reforming and achieve H 2 -rich reformates with an ultra-low concentration of CO (below 1000 ppm). This process only requires simple and low-energy purification pretreatments to meet the requirements of commercial fuel cells. Mechanistic studies reveal that the Cu−Ni alloy can adsorb CO, particularly at high temperatures, and simultaneously suppress CO dissociation to methane.
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高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Shaozhong Li,Yu Wang,Bin Yang,Limin Guo
Mesostructured catalysts with optimized microstructure and surface properties endowed them attractive catalytic performance. Herein, the mesostructured AlCeO supports with different weight ratio of Al 2 O 3 and CeO 2 have been prepared on the basis of a self-assembly sol-gel process, then 15 wt.% Cu was loaded onto the mesostructured AlCeO supports by incipient wetness impregnation method. The mesostructured AlCeO supports with varied ratio of Al 2 O 3 to CeO 2 resulted in the very different Cu particle size, and for the optimized catalyst Cu/AlCeO-7 (the amount of Al 2 O 3 in AlCeO support was 70 wt.%), the Cu crystal size was around 7 nm based on the characterization of XRD and TEM. The Cu/AlCeO-7 catalyst had strong metal-support interactions (SMSI) and more Cu-ceria interface, which was confirmed by the XPS. Furthermore, the Cu/AlCeO-7 catalyst showed the highest exposed Cu surface area ( S Cu ) (25.5 m 2 /g cat ) from the analysis results of H 2 -TPR and dissociative chemisorption of nitrous oxide. The CO 2 -TPD results demonstrated the Cu/AlCeO-7 had strong surface basicity. Hence, Cu/AlCeO-7 catalyst showed the highest space time yield of methanol (STY MeOH ). The CO 2 conversion (Cu/AlCeO-7, V(H 2 )/V(CO 2 ) = 3/1, GHSV = 6000 mL h −1 g −1 and P = 4 MPa) was up to 22.5% at 553 K, the methanol selectivity can reach 94% at 473 K, and the STY MeOH was up to 7.2 mmol g cat. -1 h -1 at 493 K. The as-prepared mesostructured Cu/AlCeO-7 exhibited a promising catalyst candidate for CO 2 hydrogenation to methanol.
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高影响因子
ACS Applied Nano Materials
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2018
·
IF 0
Xinrui Jiang,Bo Han,Chenggang Zhou,Kaisheng Xia,Qiang Gao,Jinping Wu
Hexagonal boron nitride (h-BN) with a unique 2D architecture is a promising support for catalyst due to its large surface area, high thermal stability, and chemical inertness. However, the weak interaction between h-BN and active metal particles would lead to unexpected agglomeration or loss of active components. In this work, an oxygen-rich mesoporous boron nitride (BNO) support was synthesized by a two-step calcining process, on which Cu nanoparticles were dispersed via a typical adsorption–reduction procedure. The reduction of p-nitrophenol (4-NP) was successively carried out as a model reaction to determine the catalytic performance of the Cu/BNO catalyst. Excellent catalytic activity of 4-NP reduction was implemented with a reaction rate constant of 0.692 min–1, which is maintained almost intact within five cycles. First-principles calculations suggest that the superior durability of Cu/BNO is largely attributed to the weakened conjugation effect of BNO upon O doping, which strengthens the interactions between Cu nanoparticles and BNO supports. Moreover, the doping O atom would significantly enrich the electron density of Cu, which is responsible for the superior activity toward 4-NP reduction.
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DOI
NEW JOURNAL OF CHEMISTRY
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2018
·Vol. 43
·期 4
·1812-1817
·
IF 3.201
Yang Li,Zhicheng Liu,Lu Bai,Yaqing Liu
Nitrogen-doped carbon dots were facilely synthesized via the chemical breakdown of electrospun polyacrylonitrile-based carbon nanofibers. The results of transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy demonstrated that the prepared N-doped carbon dots with a relatively narrow size distribution exhibited abundant C, N, and O containing functional groups. In the meantime, aqueous N-doped carbon dots exhibited excitation-dependent photoluminescence. Moreover, due to the quenching effect induced by the strong coordination interaction between the Cu2+ ions and the surface functional groups of the obtained N-doped carbon dots, an efficient fluorescent sensing platform was developed to detect Cu2+ ions, showing high sensitivity and selectivity to Cu2+ ions with a detection limit of 5 nM in the linear range of 0–10 μM. This work has provided a simple and effective approach for fabricating N-doped carbon dots as a promising fluorescent material for heavy metal sensing.
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高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
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2018
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IF 3.414
Bowen Pu,Junwei Sha,Enzuo Liu,Chunnian He,Naiqin Zhao
Traditional laminated metal matrix composites are confined to two-component system of pure metal matrix and its reinforcement. To achieve further improvement of the applied mechanical properties , in this work, the soft phase of laminated composites was enhanced by alloying with Cu. The synergistic effect of Cu on phases of both soft and hard including in-situ catalyzing and precipitation hardening was firstly explored. The laminated graphene nanosheets (GNSs) /AlCu composites of 2 vol% GNSs, were fabricated by ball milling and hot-rolling processes with much higher mechanical properties. The multi-pass hot rolling provided the solution-precipitation process of Cu transforming into Al 2 Cu and significantly increased the dislocation density of the original soft Al matrix. In addition, the fracture mechanism and fracture model of the laminated GNSs/AlCu composites were also investigated.
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高影响因子
ELECTROCHIMICA ACTA
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2012
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IF 3.832
Lu Xiong,Yu-Xi Huang,Xian-Wei Liu,Guo-Ping Sheng,Wen-Wei Li,Han-Qing Yu
Efficient, cost-effective and stable catalysts for cathodic oxygen reduction reaction (ORR) are highly desirable for both chemical and microbial fuel cells. Nano-materials with three-dimensional (3D) porous materials are gaining popularity recently, because of their large surface areas and numerous active sites. In this work, we prepare a unique self-supporting Pd–Cu bimetallic catalyst with 3D porous structure using a facile double-template fabrication process and evaluate its performance as an ORR catalyst. This catalyst is found to possess an electrochemically active surface area of 80.2 m 2 /g Pd , a peak current of 17.4 mA/cm 2 and an unusual limiting current density of 12 mA/cm 2 . Meanwhile, the fabricated bimetallic catalyst displays a better long-term stability than the state-of-the-art Pt/C catalyst. This work provides useful information on the facile preparation of cost-effective cathodic catalysts for chemical or microbial fuel cells in a controllable way.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2014
·Vol. 162
·期 1
·B36
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IF 2.859
Jinshou Wang,Zhen Shi,Jing Jin,Yuanbin Tan,Shenghui Zhang
A novel ordered macroporous polycysteine/Cu composite film (DOM PCE/Cu) was successfully prepared by electrochemical deposition method using polystyrene spheres as templates on a bare glassy carbon electrode (GCE). The structure and electrochemical properties of DOM PCE/Cu film were characterized. The DOM PCE/Cu composite film modified electrode exhibits good electrochemical catalytic activity toward the oxidation of glucose, which may be related to the structure of DOM PCE/Cu film. The non-enzymatic glucose sensor has a wide linear range from 2 μM to 2.9 mM, with a low detection limit of 0.8 μM. The modified electrode also has highly sensitive and fast amperometric (within 3 s) sensing of glucose, thus it can be used for the future development of non-enzymatic glucose sensor.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2015
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IF 4.513
Zhi-Chao Liu,Jian-Wen Qi,Chun Hu,Li Zhang,Wei Song,Ru-Ping Liang,Jian-Ding Qiu
Copper is a highly toxic environmental pollutant with bioaccumulative properties. Therefore, sensitive detection of Cu 2+ is very important to prevent over-ingestion, and visual detection is preferred for practical applications. In this work, we developed a simple and environmental friendly approach to synthesize hyperbranched polyethyleneimine-protected copper nanoclusters (hPEI-Cu NCs) with great stability against extreme pH, high ionic strength , thiols etching and light illumination, which were then conjugated to the surface of silica coated CdSe quantum dots (QDs) to design a ratiometric fluorescence probe. In the presence of different amounts of Cu 2+ ions, the fluorescence of Cu NCs can be drastically quenched, while the emission from QDs stayed constant to serve as a reference signal and the color of the probe changed from yellow-green to red, resulting in ratiometric and visualization detection of Cu 2+ ion with high accuracy. The detection limit for Cu 2+ was estimated to be 8.9 nM, much lower than the allowable level of Cu 2+ in drinking water (∼20 μM) set by U.S. Environmental Protection Agency. Additionally, this probe can be also applied for the determination of Cu 2+ ion in complex real water samples.
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PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 56
·45320-45330
·
IF 3.84
Guannan Wang,Limin Chen,Yuhai Sun,Junliang Wu,Mingli Fu,Daiqi Ye
Methanol synthesis from CO2 hydrogenation in a fixed-bed plug flow reactor was investigated over Cu–ZrO2 catalysts supported on CNTs bearing various functional groups. The highest methanol activity (turnover frequency 1.61 × 10−2 s−1, space time yield 84.0 mg gcat−1 h−1) was obtained over the Cu/ZrO2/CNTs catalyst (CZ/CNT-3) with CNTs functionalized by nitrogen-containing groups and Cu loading only about 10.3 wt% under the reaction conditions of 260 °C, 3.0 MPa, V(H2) : V(CO2) : V(N2) = 69 : 23 : 8 and GHSV of 3600 h−1. The catalysts were fully characterized by N2 physisorption, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR) and temperature-programmed desorption of H2 (H2-TPD) techniques. The excellent performance of CZ/CNT-3 is attributed to the presence of nitrogen-containing groups on the CNTs surface, which increase the dispersion of copper oxides, promote their reduction, decreases the crystal size of Cu, and enhances H2 and CO2 adsorption capability, thus leading to good catalytic performance towards methanol synthesis.
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 1
·
IF 1.768
Caideng Yuan,Mingtong Cui,Longlong Feng,Jingpeng Wang,Yan Peng
An amino-functionalized nano-adsorbent (DETA-MNPs) was prepared by a process involving: (1) synthesis of superparamagnetic Fe 3 O 4 nanoparticles; (2) introduction of amino groups after which ATRP initiator was anchored; (3) grafting of glycidyl methacrylate (GMA) via SI-ATRP; and (4) ring-opening reaction of epoxy groups with diethylenetriamine (DETA). The nano-adsorbent was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM) and applied to remove Cu(II) in batch experiments. The effects of pH, Cu(II) concentrations, solution ionic strength, and contact time were investigated. The results show that the DETA-MNPs are spherical with cubic spine structure, high saturation magnetization (41.9 emu g −1 ), and an average diameter of 10 nm. The maximum Cu(II) adsorption capacity achieves 83.33 mg g −1 at pH 5.0 by Langmuir model. The adsorption process is highly pH-dependent and reaches equilibrium within 20 min. Furthermore, the DETA-MNPs exhibit excellent dispersibility and reusability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132 , 42859.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2015
·
IF 2.999
Yi Cao,Baoping Lin,Ying Sun,Hong Yang,Xueqin Zhang
La x Sr 1 − x Cu 0.1 Mn 0.9 O 3 − δ (LNF- x ) (0.1 ⩽ x ⩽ 1) nanofibers are prepared by electrospun method. The structure of LNF- x and the electrochemical properties of LNF- x in 1 M Na 2 SO 4 aqueous electrolyte are investigated. As a result, LNF- x nanofibers present a perovskite structure, and the LNF-0.5 sample exhibits the highest specific capacitance value of 464.5 F g − 1 at a current density of 2 A g − 1 . The maximum energy density of 64.5 W h kg − 1 are achieved at a power density of 2 kW kg − 1 for the symmetric supercapacitor prepared by La 0.5 Sr 0.5 Cu 0.1 Mn 0.9 O 3 − δ nanofibers. More importantly, this symmetric supercapacitor also shows an excellent cycling life after 2000 charging and discharging cycles. Those results offer a suitable design of electrode materials for high-performance supercapacitors.
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高影响因子
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