Materials Today Energy
·
2020
·
IF 5.604
T. Huang,X. Huang,C. Hu,J. Wang,H. Liu,Z. Ma,J. Zou,W. Ding
In this work, one-dimensional NiMoO 4 and CoMoO 4 nanorods are prepared and introduced into MgH 2 to improve its hydrogen storage properties. It is observed that the MgH 2 –NiMoO 4 system exhibits lower dehydrogenation temperature and faster kinetics than the MgH 2 –CoMoO 4 system and pure MgH 2 , indicating the superior promoting effect of NiMoO 4 over CoMoO 4 . Concretely, NiMoO 4 reacts with MgH 2 during the first dehydrogenation to in situ form Mg 2 Ni and Mo 0 , both of which are crucial factors for the following hydrogen cycling process. The ‘Mg 2 Ni/Mg 2 NiH 4 ’ mutual transformation upon hydrogen release/uptake is the well-known ‘hydrogen pump’ effect which boosts the hydrogen storage performance of MgH 2 . Moreover, theoretical calculations reveal the dual roles of Mo 0 played for the hydrogen storage in MgH 2 : i) it accelerates the hydrogen de/absorption of MgH 2 through weakening the Mg–H bonding; ii) it facilitates the mutual ‘Mg 2 Ni/Mg 2 NiH 4 ’ transformation as the formation energy of Mg 2 NiH 4 decreases under the influence of Mo 0 , which we call ‘facilitated hydrogen pump’ effect in this work. Ascribing to the collaborative action between Ni- and Mo- containing species, the hydrogen storage kinetics of MgH 2 has been accelerated.
研究领域:
材料科学
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纳米材料
·
能源化学
·
固态储氢
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金属氢化物
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催化材料
·
理论计算
✓ 已验证
DOI
高影响因子
JOURNAL OF AEROSOL SCIENCE
·
2019
·
IF 2.24
Jili Wei,Yihua Ren,Yiyang Zhang,Baolu Shi,Shuiqing Li
This work examines the effect of temperature-time history on the flame synthesis of titania nanoparticles using a specially designed swirl-stabilized tubular burner with two kinds of precursor feeding modes, the tangential inlet and the central jet inlet. When the Damköhler number is less than unity, a rapidly mixed type tubular flame is well-formed, which is chosen to be the condition for flame synthesis. The ex situ characterization of the synthesized TiO 2 nanoparticles shows that the particle samples from the tangential inlet feeding mode are mainly anatase (up to 84.3%) with a mean primary particle size of 13.0 ± 3.2 nm, whereas those from the central jet inlet feeding mode are large polydisperse rutile (up to 74%) nanoparticles with a mean size of 16.9 ± 8.8 nm. The significant differences in particle size and crystal phase are attributed to the varied temperature-time histories of two feeding modes, as the residence time of nanoparticles in high-temperature zone of the central jet inlet mode is much longer with larger variation than that of the tangential inlet feeding mode. Finally, the well-dispersed Pd/TiO 2 nanocatalysts are generated by elaborately feeding palladium acetate through the central jet inlet and titanium tetraisopropoxide through the tangential inlets, respectively, to better match the temperature-time histories with the decomposition properties of two different precursors. The study demonstrates the potential of this swirl-stabilized burner for producing tailored single- and multi-component nanomaterials for a variety of applications.
研究领域:
材料科学
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纳米技术
·
燃烧化学
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催化材料
·
热力学过程
·
功能纳米材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Lele Cui,Peipei Ding,Ming Zhou,Wenheng Jing
Electrochemical technology offers the possibility of in situ hydrogen peroxide generation whose productivity greatly depends on the cathode properties and the reactor configuration. Herein, cerium oxide modified graphite felt is prepared and used as cathode. Ceramic membrane is integrated dividing the cell to two compartments and preventing decomposition of cathode-generated H 2 O 2 at the anode. H 2 O 2 is found almost impermeable through the membrane as concentration difference <0.5 M. The double-cell reactor performs higher energy efficiency than the conventional electrolytic cell. And H 2 O 2 accumulation rate has been enhanced in the double-cell in comparison with the undivided one, no matter using either bared or modified cathode. Operation parameters including flow rate of O 2 ( F O 2 ), flow rate of electrolyte solution (F solution ), applied current (I) and pH were optimized. Accumulated concentration of H 2 O 2 on the modified cathode reached 260.7 mg/L with the current efficiency up to 75.7% (working conditions C Na 2 SO 4 = 0.05 M, pH = 2, I = 50 mA, F O 2 = 0.2 L/min and F solution = 800 μL/min). The yield was 3.8 times higher than using the unmodified cathode. Energy consumption was reduced to 4.8 kWh/kg in the double-cell system (22.1 kWh/kg in the single-cell). In a conclusion, the double-compartment flow reactor is an improved configuration for energy effectiveness and increased productivity of H 2 O 2 for E-Fenton process.
研究领域:
环境工程
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电化学工程
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材料科学
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能源技术
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水处理技术
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反应器设计
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催化材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2015
·Vol. 23
·期 2
·301-310
·
IF 1.108
Ye Wei,Zhao Binxia,Gao Han,Huang Jiajun,Zhang Xiaoli
Fe,Zn,Al-pillared montmorillonite (Mt) were prepared by ion exchange reaction. Effect of the Fe/Zn molar ratio in Fe,Zn,Al-pillaring solution on the structural properties of Fe,Zn,Al-Mt was examined. Characterization studies were performed by N 2 -adsorption/desorption, ICP, FTIR, DR UV–Vis spectroscopy and XRD. The interlayer space, specific surface and volume of micropores of pillared-Mt was 18.8 Å, 157 m 2 g −1 and 0.114 cm 3 g −1 respectively. Besides, the catalytic performance of Fe,Zn,Al-Mt was analyzed through wet peroxide oxidation of Orange II under mild experimental condition. The results indicated that the catalytic performance of Fe,Zn,Al-Mt was affected by the Fe/Zn molar ratio as following pattern: the obtained pillared solids with lower Fe/Zn molar ratios exhibited better catalytic performance and less iron leaching during the reaction. Moreover, the introduction of zinc into Mt shortened the induction time of reaction and improved the catalytic behaviour. Throughout this work, the chemical oxygen demand removal of OII was 77.1 % after the solution treated by Fe,Zn,Al(3/7)-Mt (defined as the Fe/Zn molar ratio of 3/7 in the pillaring solution) catalyst at temperature of 60 °C and atmospheric pressure of 1 atm.
研究领域:
环境化学
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催化材料
·
废水处理
·
无机非金属材料
·
表面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）