INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2020
·
IF 4.939
Yinghui Sun,Guojie Zhang,Haizhu Cheng,Jun Liu,Guoqiang Li
The mechanism and kinetic features of dry reforming with methane (DRM) over Ca promoted 1Co–1Ce/AC-N catalyst was investigated. The mechanistic pathway studies have conducted by FTIR and XPS analysis, structure-activity correlations demonstrated the CH 4 and CO 2 could adsorb on catalyst active sites and generate intermediate CH x , OH and CH x O, continue to generate CO and H 2 and then desorbed from active sites. Moreover, CH 4 could also oxidized by Ce 4+ and CO 2 reduced by Ce 3+ , the same content of Ce 4+ and Ce 3+ on promoted catalyst greatly improved the reaction rate. The kinetic of dry reforming with methane was examined for temperature between 650 and 850 at 800 °C. The research was carried out by changing the CH 4 /CO 2 ratios between 0.3 and 3.0. The obtained experiment data were fitted by three typical kinetic models (Power Law, Eley-Rideal and Langmuir-Hinshelwood), the fitting results demonstrated that the best prediction of reforming rates can provided by Langmuir-Hinshelwood model for the reaction temperatures between 650 and 800 °C. Moreover, activation energies of methane and carbon dioxide consumption were −117 and −47 kJ/mol, indicating that much higher energy barrier is needed for methane activation compared to carbon dioxide.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 35
·14970-14978
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IF 3.288
Jingchuang Zhao,Yingzhen Zhang,Xianyu Kang,Yancai Li
Direct methanol fuel cells (DMFCs) have been extensively studied for developing a new non-precious metal catalyst to replace commercial platinum catalysts, due to their expensive cost and susceptibility to CO poisoning. In this work, nanocomposites of nickel oxide/nickel supported by N-doped carbon (NiO/Ni–N/C) were prepared by using a hydrothermal method and further carbonization at different temperatures. The surface morphology and composition of the NiO/Ni–N/C nanocomposites were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). As observed through electrochemical experiments, the NiO/Ni–N/C nanocomposite modified glassy carbon electrode (NiO/Ni–N/C/GCE) exhibits high electrocatalytic activity for the methanol oxidation reaction (MOR) in alkaline solution. Among the nanocomposites, NiO/Ni–N/C carbonized at 500 °C (NiO/Ni–N/C500) displays the highest mass activity (1043 mA mgNi−1) at 0.73 V (vs. Ag/AgCl), which is much higher than that of Ni(OH)2/N–C and NiO/Ni–N/C carbonized at other temperatures (400, 600, and 700 °C). In addition, the catalytic activity of NiO/Ni–N/C500 is 2.12 times that of the commercial Pt/C. NiO/Ni–N/C500/GCE also possesses fast kinetics, excellent stability and CO tolerance. Therefore, the NiO/Ni–N/C500 nanocomposites have great application potential as MOR catalysts.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Haoqing Lin,Jiao Xie,Zhenbao Zhang,Shaofeng Wang,Dengjie Chen
We applied a novel solid-liquid co-electrospinning approach to synthesize hybrid LaCoO 3 perovskite nanoparticles@nitrogen-doped carbon nanofibers (LCNP@NCNF) as an effective and robust electrocatalyst for Zn-air batteries. LCNP@NCNF featured an integrated structure with well-crystallized perovskite nanoparticles uniformly distributed in micro/mesoporous NCNF. In addition, LCNP@NCNF exhibited a high specific surface area of ~183.3 m 2 g −1 and a large pore volume of ~0.164 m 3 g −1 . The rotating-electrode measurement revealed the better intrinsic activity and more favorable stability of LCNP@NCNF in comparison with their counterparts. Moreover, Zn-air batteries employing LCNP@NCNF showed a relatively smaller discharge-charge voltage gap of ~0.95 V and longer cycling stability than the battery adopting the physically blended LCNP and NCNF. We ascribed the improved electrochemical activity to the enhanced synergistic interaction originating from the successful coupling of LCNP and NCNF.
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PubMed
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
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2020
·Vol. 49
·期 9
·1237-1249
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IF 1.273
Li Dan,Guo Meng,Wu Qian,Li Menglei,Ruan Nannan,Gao Lijun
The density, viscosity and excess properties of biodiesel–alcohol fuel blends are investigated for research into the blending of fuels. Four n -alkanols (1-propanol, 1-butanol, 1-pentanol and 1-hexanol) as additives were mixed with ethyl laurate to form binary systems for density and viscosity measurement. Excess molar volumes and viscosity deviations of the four binary systems (1-propanol + ethyl laurate), (1-butanol + ethyl laurate), (1-pentanol + ethyl laurate), and (1-hexanol + ethyl laurate) were calculated from the experimental density and viscosity data and fitted with the Redlich–Kister equation. Grunberg–Nissan and McAllister equations were used to correlate viscosities and the correlated values from McAllister equation are in good agreement with the experimental data. The results may be useful for the research and development of biodiesel–alcohol fuel blends.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Wei Peng,Xiaoxiao Yang,Linchang Mao,Junhong Jin,Shenglin Yang,Jingjing Zhang,Guang Li
Developing highly active and robust bifunctional non-precious oxygen electrocatalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is of paramount importance for enhancing the efficiency of zinc-air battery. Herein, Co nanoparticles anchored in N doped hollow and porous carbon nanofibers (CoN-HPCNF) are obtained via an in-situ growth-pyrolysis approach with the hybrid of ZIF-67 and carbon nanofibers as the precursor. Originating from its high surface area, firm and hierarchical porous structure, effective doping of N as well as synergistic effect from Co nanoparticles and HPCNF, the optimized CoN-HPCNF shows prominent bifunctional catalytic activity and long-term stability toward OER and ORR. Importantly, the assembled aqueous zinc-air battery with the prepared catalyst as the air cathode delivers a peak power density of 126.6 mW cm −2 and narrow charge-discharge voltage gap together with excellent operation durability (more than 280 h at the current density of 5 mA cm −2 ), outdoing the commercial precious metal catalysts (Pt/C + IrO 2 ).
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INTERNATIONAL JOURNAL OF ENERGY RESEARCH
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2020
·Vol. 45
·期 5
·7120-7128
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IF 3.741
Menglu He,Jia Jia,Qing Sun,Weixin Zhang
SUMMARY Li-O 2 battery has attracted much attention due to its ultra-high theoretical energy density in the field of electrochemical energy storage. The introduction of efficient electrocatalyst can effectively accelerate the reaction rate of ORR and OER, so as to improve the coulomb efficiency and poor cycle stability of Li-O 2 battery. In this work, a novel hollow N-doped carbon sphere is prepared by using MOF and polystyrene as template, and act as highly efficient oxygen electrocatalyst for rechargeable Li-O 2 batteries. The hollow structure can provide enough oxygen diffusion channel, deposition and decomposition space for reduction products. N doping into the hollow carbon structure can increase the charge density of adjacent carbon atoms and enhance its catalytic activity of ORR/OER. As a result, the Li-O 2 battery using the hollow N-doped carbon sphere as air cathode exhibited an high specific capacity of 18 762 mAh/g (at a current density of 500 mA/g) and remarkable cycling stability of 212 cycles (at a current density of 500 mA/g and limited capacity of 1000 mAh/g), outperforming the carbon material with common structure. This work highlights the importance of air cathode structure and efficient catalyst, provides a new idea for the design of air cathode of Li-O 2 battery, and expands the scope of future research.
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Mengge Shang,Jing Zhang,Xiaochan Liu,Yi Liu,Sipeng Guo,Shimo Yu,Serguei Filatov,Xibin Yi
A novel N, S self-doped hollow-sphere porous carbon is directly prepared from abundant biomass puffball spores via a simple carbonization and KOH activation process for the first time. The electrochemical properties and porous structure of these carbons are explored by adjusting the amount of KOH. It is found that the obtained N, S self-doped hollow-sphere porous carbon with a KOH to carbon mass ratio of 4 (NS-HPC-4) exhibits the largest specific surface area (1431 m 2 /g), a well-developed hierarchical porous structure and moderate N/S contents. As a result, the NS-HPC-4 electrode in the supercapacitor delivers a large specific capacitance of 285 F/g at 0.5 A/g in KOH electrolyte. Furthermore, the symmetric supercapacitor based on NS-HPC-4 exhibits an energy density of 10.9 Wh/kg at a power density of 400.4 W/kg in 2 M KOH aqueous electrolyte, and achieves a high energy density of 58.4 Wh/kg at a high power density of 876.0 W/kg in 1 M Et 4 NBF 4 /AN organic electrolyte. These excellent results confirm that puffball spores derived porous carbons are promising candidates to be used in high performance supercapacitors.
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高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2020
·Vol. 26
·期 63
·14496-14501
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IF 4.857
You Xu,Xingjie Chai,Mengying Liu,Tianlun Ren,Shanshan Yu,Ziqiang Wang,Xiaonian Li,Liang Wang,Hongjing Wang
Graphical Bifunctional electrocatalysts : Two-dimensional NiIr@N-doped carbon nanocomposites supported on Ni foam substrate function as bifunctional electrocatalysts for overall water splitting in alkaline conditions. Electrochemical water splitting can provide a promising avenue for sustainable hydrogen production. Highly efficient electrocatalysts toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are extremely important for the practical application of water splitting technology. Herein, a one-step annealing strategy is reported for the fabrication of a metal–organic framework-derived bifunctional self-supported electrocatalyst, which is composed of two-dimensional N-doped carbon-wrapped Ir-doped Ni nanoparticle composites supported on Ni foam (NiIr@N-C/NF). The resultant NiIr@N-C/NF displays excellent electrocatalytic performance in 1.0 m KOH, with low overpotentials of 32 mV at 10 mA cm −2 for the HER and 329 mV at 50 mA cm −2 for the OER. Particularly, the HER-OER bifunctional NiIr@N-C/NF needs only 1.50 V to yield 10 mA cm −2 for overall water splitting.
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PubMed
高影响因子
FOOD CONTROL
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2020
·
IF 4.258
Xuefei Shao,Baocai Xu,Hui Zhou,Conggui Chen,Peijun Li
The mechanism of decreasing N- nitrosodimethylamine (NDMA) by Lactobacillus pentosus R3 isolated from Chinese dry sausage was assessed in a model system. The model system was devised using a DeMan-Rogosa and Sharp-ferrous sulfate broth supplement with NDMA or its precursors. The results showed that inoculating L. pentosus R3 could significantly decrease the content of NDMA ( P < 0.05). The NDMA precursors (dimethylamine and putrescine) were found to be decreased by L. pentosus R3 ( P < 0.05). Nitrite was degraded to nitrosonium cation by acidolysis, which may promote the formation of NDMA. Direct degradation of NDMA by L. pentosus R3 was also observed. The strain exhibited antioxidant activities , including Fe 2+ chelating activity, which may be responsible for inhibiting the formation reaction and decreasing the precursors of NDMA. Thus, L. pentosus R3 decreased the content of NDMA possibly by three ways: inhibition of the formation reaction, decrease in precursors (DMA and putrescine) and direct degradation. It is interesting to understand the mechanism of decreasing NDMA by L. pentosus R3 to improve the safety of fermented meat products .
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高影响因子
CELLULOSE
·
2020
·Vol. 27
·期 15
·9075-9089
·
IF 4.21
Chen Yu,Wang Dingfei,Liu Shidong,Lu Yonghua,Zhang Guangxian,Zhang Fengxiu
Abstract A novel P–N based, flame retardant ammonium salt of pentaethylenehexamine octa (methylene-phosphoric acid) (APHOMPA) was synthesized in this study. The structure of the prepared material flame retardant contains eight reactive ammonium phosphorus groups and was characterized by 1 H NMR, 13 C NMR, 31 P NMR, and (Fourier-transform infrared) FT-IR. The results showed that cotton fabrics finished with this flame retardant exhibited excellent flame retardancy and durability. The cotton fabrics finished with 30% APHOMPA solution had limiting oxygen index value 40.5%, and maintained 28.8% even after 50 laundering cycles. The FT-IR results showed that APHOMPA could be grafted on cellulose through P–O–C covalent bond. Vertical flammability, cone calorimetry, thermogravimetric (TG), and TG-IR results revealed the excellent flame retardancy of the finished cotton fabrics and suggested that the flame retardant mechanism of APHOMPA is a condensed phase process. Scanning electron microscopy results suggested the flame retardant entered the inner space of the cotton fabrics, and the X-ray diffraction results showed slight changes to the cotton crystal structure in the finishing process. The breaking strength, softness, and whiteness of finished cotton fabrics were sufficient, suggesting this retardant can be used to prepare treated cotton for multiple applications. Graphic abstract
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高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Junwei Cui,Shengshan Bi,Andreas P. Fröba,Jiangtao Wu
The present work focus on the measurement of viscosity and interfacial tension of n -heptane ( n -C 7 H 16 ) with dissolved carbon dioxide (CO 2 ) by the surface light scattering. The method allows an absolute determination of both properties in a contactless way. The experiments were conducted in macroscopic thermodynamic equilibrium at temperatures from (298 to 473) K and saturation pressures up to 5.5 MPa. For sample preparation of binary mixtures of n -C 7 H 16 with dissolved CO 2 after its addition, the equilibration process could be checked to be completed by showing that viscosity and interfacial tension are independent on time. For reaching equilibrium, at least two hours were elapsed between the addition of CO 2 and the start of the measurement. For both viscosity and interfacial tension, typical expanded uncertainties are 3% on a confidence level of 95%. The viscosity results were correlated with an empirical equation, where the absolute average deviation (AAD) and the maximum absolute deviation (MAD) between experiments and correlation were 1.9% and 7.2%, respectively. For the viscosity, a data comparison was hindered because of the lack of literature data. For the interfacial tension, which can also be represented by an empirical correlation and good agreement with literature can be found.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Li Wang,Lili Cui,Xin Ge,Nailin Yue,Xingquan He,Wei Zhang,Tewodros Asefa
Developing efficient nonprecious electrocatalysts that can drive the oxygen electrode reactions in zinc-air batteries (ZABs) is important but remains challenging. In this work, novel materials comprising Mn/Cu nanoclusters-grafted N-doped carbon nanotubes are synthesized by preparing and then pyrolyzing Mn/Cu polyphthalocyanine-encapsulated carbon nanotubes (CNTs), followed by treating the products with acidic solution. The materials are named CNTs@(Mn,Cu)PPc-T, where T denotes the pyrolysis temperature in °C, and they are demonstrated to serve as efficient oxygen electrode catalysts for zinc-air batteries (ZABs). Among them, the one synthesized at 900 °C, CNTs@(Mn,Cu)PPc-900, requires more positive onset and half-wave potentials for reduction of oxygen and a low overpotential for the evolution of oxygen. A rechargeable ZAB assembled with CNTs@(Mn,Cu)PPc-900 electrocatalyst delivers a high power density (158.5 mW cm −2 ) and displays an excellent stability in 200 cycles of charge/discharge (in over 33 h). Such performance is even superior to that of a ZAB containing the benchmark Pt/C + RuO 2 catalyst as an air cathode under identical testing condition.
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