ACS Sustainable Chemistry & Engineering
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2019
·
IF 6.97
Chunyu Li,Chao Wu,Baoquan Zhang
Blending porous inorganic fillers into polymers to fabricate mixed matrix membranes (MMMs) is an efficient method to acquire good-quality membranes for CO2 separation and purification. The poor interface coupling between bulky filling particles and polymer phase in MMMs results in reduced mechanical strengths with low separation performances. The novel two-dimensional (2D) and ultrathin α-Ni(im)2 nanosheets with high aspect ratios are herein synthesized and blended with Pebax MH 1657 to prepare MMMs. The larger contacting area and strong hydrogen bonding between α-Ni(im)2 nanosheets and Pebax improve their compatibility to form defect-free MMMs. The ultrathin α-Ni(im)2 nanosheets in MMMs can effectively enhance CO2/CH4 selectivity based on molecular sieving. With the addition of 2 wt % of α-Ni(im)2 nanosheets, the as-prepared MMMs exhibit CO2/CH4 selectivity up to 33.4 with a permeability of 100.6 Barrer. Compared with pure Pebax membrane, the separation selectivity shows a 72% increase with no significant change in CO2 permeability.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2019
·Vol. 49
·期 2
·1043-1050
·
IF 1.676
Jiao Yunpeng,Han Yinghui,Pang Yiheng,Zhou Junxiu,Qi Xiaohan,Liu Yunpeng
Abstract Some kinds of the plate-like hexagonal layered double complex hydroxides (named Ni-Fe-Sr-LDHs) materials were prepared for energy storage electrodes in this work. It showed good properties with energy densities and cycle life through the electrochemical tests. At 1 A g −1 current density, the specific capacitance of the electrode reached 311.02 F g −1 when the electrolyte was 6 M LiOH. In the long cycle test, the capacitance retention of the electrode maintained at 73.16% after 2000 cycles (current density: 1 A g −1 ). The morphologies of Ni-Fe-Sr-LDHs were characterized via the scanning electron microscope, transmission electron microscopy and x-ray powder diffraction. The prepared layered double hydroxides were further optimized by doping carbon nanotubes (CNTs). The optimal weight ratio of Ni-Fe-Sr-LDHs to CNTs was 3:1. The specific capacitance in the measurement of galvanostatic charge–discharge increased to 438.74 F g −1 , and the stability of long-term cycling was raised to 77.45%. These results indicated that Ni-Fe-Sr-LDHs combined with CNTs would be an ideal electrode material for practical energy storage. Graphic Abstract
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高影响因子
Green Energy & Environment
·
2019
·
IF 0
Xiaolan Deng,Yuqi Jiang,Zengxi Wei,Minglei Mao,Ramyakrishna Pothu,Hongxia Wang,Caiyun Wang,Jinping Liu,Jianmin Ma
Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-ion asymmetric supercapacitor (ASC) with Ni(OH) 2 and Nb 2 O 5 nanosheets directly grown on stainless steel mesh is developed. In the dual-ion ASC, Nb 2 O 5 negative and Ni(OH) 2 positive electrodes react with Li + and OH − respectively in alkaline gel electrolyte to store energy, which is quite different from conventional alkali metal ion SCs and alkaline SCs. The as-assembled flexible device has an extended working voltage of 1.7 V and delivers a capacity of 5.37 mAh cm −2 , a maximum energy density and power density of 0.52 mWh cm −3 and 170 mW cm −3 , respectively. The device maintains around 60% capacity retention after long cycling up to 1000 cycles. Moreover, our device can light up a LED light efficiently upon fast charging. The proposed quasi-solid-state dual-ion ASC has potential applications in future portable electronics and flexible energy storage devices.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Baosong Li,Dandan Li,Jun Zhang,Wei Chen,Weiwei Zhang
The incorporation of TiN and Y 2 O 3 nanoparticles together into Ni-W matrix have been investigated by pulse electrodeposition in present study. The microstructural, surface properties and corrosion resistance of Ni-W/TiN-Y 2 O 3 nanocrystalline coating have been studied. It illustrated that the electrodeposited coatings have dense and nodular structure without defects. Results confirmed that TiN and Y 2 O 3 particles were uniformly embedded in the composites. The embedded particles could improve the hardness and anti-corrosion properties of the obtained coating. The crystallite size calculated based on the preferred orientation (111) plane was of 14–17 nm, illustrating the formation of nanocrystalline structure. The mean R a value was about 84.6 nm. Electrochemical impedance tests revealed that the preferred combination of operating parameters for optimum corrosion resistance was 70%, 1000 Hz, 40 min and 4 A dm −2 . However, the best hardness and anti-wear properties were obtained at parameters of 50%, 500 Hz, 6 Adm −2 and 60 min. The extreme values of hardness and corrosion resistance were not realized simultaneously. The operating parameters should be kept in a certain balance to avoid the formation of inferior properties in any aspects of the coating; then the other performance advantages could be brought into full play. The preferred combination of operating parameters was optimized to be duty cycle of 70%, frequency of 1000 Hz, duration time of 40 min and average current density of 4 Adm −2 , which enabled the electrodeposited coating optimum corrosion resistance and high mechanical properties .
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高影响因子
FUEL
·
2019
·
IF 5.128
Ze Zhang,Jun Cheng,Yi Qiu,Xi Zhang,Junhu Zhou,Kefa Cen
To clarify the conversion mechanism of methyl palmitate (C16:0) to produce jet biofuel over Ni/desilicated meso-Y zeolite catalyst, quantum chemistry calculation and verification experiments were conducted to evaluate three proposed competitive reaction pathways, in which hydrodecarboxylation pathway was more feasible than hydrogenolysis and decarboxylation pathways. It was found that overall enthalpy change to produce pentadecane (−130.2 kJ/mol) in hydrodecarboxylation pathway was lower than that to produce palmitic acid (−90.1 kJ/mol) in hydrogenolysis pathway and that to produce hexadecane (−68.6 kJ/mol) in decarboxylation pathway. The experimental results of hydrodeoxygenation and hydrocracking conversion of methyl palmitate into jet biofuel were consistent with quantum chemistry calculation, when conventional Y zeolite was modified into hierarchical mesoporous Y zeolite catalyst by desilication with NaOH and then loading Ni nanoparticles. The jet biofuel product selectivity reached a peak (64.8%) with reasonable composition distributions, when Ni/meso-Y zeolite was desilicated with 0.4 M NaOH to promote BET surface area (554.9 m 2 /g) and specific pore volume (0.340 cm 3 /g) with 2–10 nm mesopores. The relative content of pentadecane in liquid products was always higher than those of palmitic acid and hexadecane over Ni/meso-Y zeolite catalysts desilicated with various concentrations of NaOH. The main compositions of gas phase by-products in hydrodeoxygenation and hydrocracking conversion were CH 4 with selectivity up to 25.2% and CO 2 with selectivity of ∼10%, which agreed well with quantum chemistry calculation results.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2019
·
IF 4.084
Jianshuo Zhang,Kun Hou,Qianqian Yao,Chuxin Wu,Meihua Huang,Lunhui Guan
Transition metal phosphides represent a class of promising electrocatalysts for electrochemical water oxidization and other energy conversion reactions. In this work, we report a novel seal strategy, followed by a second step phosphorization treatment, produces Ni-Fe-P heterostructure directly grown on nickel foam that shows highly catalytic activity for electrochemical water oxidation . The as-prepared catalyst exhibits an excellent electrocatalytic activity , manifested by a current density of 20 mA cm −2 with a very low overpotential (260 mV) for oxygen evolution reaction along with an extremely small Tafel slope of 27 mV decade −1 and a very excellent durability of 120 h in alkaline solution. The excellent performance with exceptional durability owe much to the synergistic effect between the Ni-Fe-P heterostructure and the outer oxidized layer. Remarkably, a current density of 10 mA cm −2 was reached at a low cell voltage of 1.63 V when the original electrode and surface oxidized electrode are used as cathode and anode , respectively.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 9
·8768-8778
·
IF 2.914
Sun Yufeng,Liu Zongtang,Fei Zhenghao,Li Changshun,Chun Yuan,Zhang Aimin
Fe-Ni bimetallic nanoparticles supported on CNTs (Fe-Ni/CNTs) were synthesized, characterized, and applied for removal of 2,4-dichlorophenol (2,4-DCP) in aqueous solution. The removal performance was enhanced drastically on Fe-Ni/CNTs with respect to monometallic Fe/CNTs. The synergistic effect between Fe-Ni nanoparticles and CNTs has been studied in detail. The research results indicated that the doping of Ni played an important role in promoting the catalytic degradation of 2,4-DCP. And the presence of CNTs not only could effectively reduce the aggregation of nanoparticles but also facilitate the mass transfer of 2,4-DCP and the formation of active atomic hydrogen during the catalytic process. In addition, the removal kinetics of 2,4-DCP by Fe-Ni/CNTs were in agreement with a pseudo-first-order model, and the rate constants were dependent on a number of factors including the initial concentration of 2,4-DCP, the dosage of Fe-Ni/CNTs, pH value of the solution, and doping amount of Ni. The degradation mechanism involved the adsorption by CNTs and catalytic reduction by Fe under the stimulating of Ni, and the preferred dechlorination followed the order of para-Cl > ortho-Cl. The study confirmed that Fe-Ni/CNTs had a potential to be a promising catalytic material for removal of chlorophenol and had a great prospect for practical application.
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PubMed
高影响因子
FUEL
·
2019
·
IF 5.128
Xiangping Li,Jianguang Zhang,Bin Liu,Juping Liu,Chuanbin Wang,Guanyi Chen
Non-noble metal(s)-based mesoporous catalysts are one of the promising catalysts for aqueous phase hydrodeoxygenation of lignin-derived phenols to produce hydrocarbons. In this paper, Ni/Al-SBA-15 was prepared through incipient wetness impregnation method and the performance of eugenol hydrodeoxygenation over Ni/Al-SBA-15 was studied. The effect of incipient wetness impregnant on the performance of eugenol hydrodeoxygenation over Ni/Al-SBA-15 was investigated. The materials were characterized by XRD, N 2 -sorption, TEM, FTIR, Py-FTIR, XRF and ICP-MS. In comparison with the traditional incipient wetness impregnation using water as solvent, the activity of Ni/Al-SBA-15 was significantly improved by using ethanol as solvent during the process of incipient wetness impregnation. For Ni/Al-SBA-15, the quantity of total acid was decreased after loading nickel species which was mainly due to the decrease of Lewis acid sites. The strength of Lewis acid in Ni/Al-SBA-15 prepare with ethanol as impregant was enhanced. The yields of propyl cyclohexane and propylbenzene from aqueous phase hydrodeoxygeation of eugenol over Ni/Al-SBA-15-E were increased. The super catalytic behavior of Ni/Al-SBA-15-E was attributed to the synergistic effect between the stronger Lewis acid sites and the intact framework structure of Ni/Al-SBA-15-E.
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高影响因子
Nanoscale
·
2019
·Vol. 11
·期 8
·3506-3513
·
IF 6.97
Manyi Gao,Yongsheng Yu,Weiwei Yang,Ji Li,Shichong Xu,Ming Feng,Haibo Li
The development of a robust and low-cost non-noble metal catalyst for photocatalytic H2 evolution is of great importance for practical applications. In this study, monodisperse Ni nanoparticles of controlled sizes were prepared by a facile method and anchored on graphitic carbon nitride (g-C3N4) nanosheets via a self-assembly route. The noble-metal-free Ni/g-C3N4 composite catalysts exhibit excellent photocatalytic activities for the hydrolytic dehydrogenation of ammonia borane (AB) under visible light. An optimum AB hydrolysis rate was obtained when the size of the Ni NPs was 3.2 nm, with an initial turnover frequency of 18.7 mol(hydrogen) mol(catalyst)−1 min−1 and an apparent activation energy of 36 kJ mol−1. This study provides validity for constructing high performance first-row transition metal nano-photocatalysts for the hydrolytic dehydrogenation of AB.
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PubMed
高影响因子
CRYSTENGCOMM
·
2019
·Vol. 21
·期 9
·1416-1422
·
IF 3.382
Wen Zhou,Ming Zhou,Jingrui Hu,Hongmei Dong,Yingqing Ou,Lin Yang,Xijun Wei,Peng Xiao,Yunhuai Zhang
Shape-controlled synthesis of non-noble metal nanocrystals (NCs) is vital to their catalysis applications due to their different exposed surfaces and atomic coordination environments. Here, we report a facile synthesis of Ni nanocubes and cuboctahedra with controlled shapes and high yields via a wet-chemistry strategy. The key to success relies on the use of cetyltrimethyl ammonium bromide (CTAB), formaldehyde (HCHO) and a specific reaction temperature, which could effectively cap the desired surface and tune their growth rate. Specifically, nanocubes switched to cuboctahedra and octahedra with an increased reaction temperature due to gradual CO desorption from the surfaces of NCs. Meanwhile, it should be worth noting that CTAB and the generated CO molecules through HCHO decomposition would co-adsorb on the {100} facets of Ni NCs. As a proof-of-application, the obtained Ni NCs exhibited high activity in the oxygen evolution reaction (OER) with over-potentials of 383 mV and 402 mV for nanocubes and cuboctahedra at a current density of 10 mA cm−2, respectively, demonstrating that the {100} facets are more favorable toward OER. These results suggested that their performance is strongly shape dependent and is derived from different surface energies and active sites.
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高影响因子
Catalysts
·
2019
·Vol. 9
·期 8
·632
·
IF 3.444
Kirill Alferov,Shuanjin Wang,Tianhao Li,Min Xiao,Shanyue Guan,Yuezhong Meng
Synthesis of copolymers from carbon dioxide (CO2) and epoxides is an important research direction as such processes utilize the abundant greenhouse gas and deliver useful products. Specifically, cooligomers of CO2and propylene oxide (PO) with a non-alternating structure can be used for polyurethane preparation. They are synthesized by employing Zn-Co cyanide catalysts. The application of alternative metal cyanide complexes is interesting from scientific and practical points of view. The purpose of this work was to study the copolymerization of CO2and PO in the presence of Co-Ni cyanide catalysts and chain transfer agents (CTAs) in order to obtain low molecular weight products. Three Co-Ni catalysts with different contents of complexing agents were synthesized, characterized by several analytical methods and applied for this reaction. The complex without complexing agents was chosen for detailed investigation. 1,6-Hexanediol proved to be a more preferred CTA than poly(propylene glycol) and adipic acid. An oligo(ethercarbonate) (Mn= 2560, PDI = 2.5, CO2= 20 mol.%) capped with OH groups was synthesized with relatively high productivity (1320 gPO+CO2/gcatin 24 h) and characterized by matrix-assisted laser desorption/ionization (MALDI) MS and NMR methods. The main chain transfer routes during the cooligomerization were suggested on the basis of the research results.Keywords:metal cyanide catalyst;cobalt;nickel;carbon dioxide;propylene oxide;copolymerization;chain transfer agent;oligo(ethercarbonate);polyurethanes
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高影响因子
CATALYSIS COMMUNICATIONS
·
2019
·
IF 3.674
Wei Wang,Feng Xu,Wenqiao Du,Long Zhang
A facile and efficient one-pot synthesis of methyl carbamate (MC) by urea and methanol was studied using metal modified fluorapatite as a catalyst. M 5 Ca 5 (PO 4 ) 6 F 2 (M 5 FAP, M = Co, Ni, Cu, Zn) was synthesized by co-precipitation. Among the catalysts, Zn 5 Ca 5 (PO 4 ) 6 F 2 (Zn 5 FAP) displayed the higher activity, selectivity and excellent stability after five times of reuse. A possible synthesis reaction mechanism over Zn 5 FAP catalyst was discussed.
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高影响因子
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