INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2011
·Vol. 36
·期 14
·8203-8208
·
IF 4.057
Z.G. Zhang,H. Wang,M. Zhu
The major challenge of complex hydride for hydrogen storage is to release hydrogen at a moderate temperature with rapid kinetics. This paper reports a new composite system (NaBH 4 /ZnF 2 ) to generate hydrogen at a low temperature below 100 °C. The NaBH 4 and ZnF 2 mixture was prepared by a mechanical milling in a 2:1 M ratio. Dehydrogenation of the mixture during a heating process shows that the initial dehydrogenation temperature was below 100 °C with favorable kinetics. The structural analysis confirmed the formation of NaBF 4 and Zn in the reaction products. The study concerning the reaction mechanism reveals that ZnF 2 plays a role of reagent rather than catalyst. The produced intermediate of NaZnF 3 , however, affects the decomposition of the emitted B 2 H 6 . This work suggests that the extension of the decomposition mechanism of NaBH 4 /ZnF 2 composite system would favor the development of new catalysts for complex hydride systems.
研究领域:
材料科学
·
能源化学
·
无机化学
·
储氢技术
·
纳米催化
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2017
·
IF 4.364
Puhong Wen,Lili Ai,Taotao Liu,Dengwei Hu,Fangyi Yao
The regular orthorhombic Nb 2 O 5 (O-Nb 2 O 5 ) rectangle nanosheets dominantly exposed (010) facet are synthesized by a hydrothermal topological reaction with a precursor of K 4 Nb 6 O 17 ·4.5H 2 O (KNbO). The structure and morphology of the samples obtained at different temperatures and pH values of reacting solution are investigated. The results suggest that there are two topological reactions in this process. One is the acid-exchanging reaction transforming into H 4 Nb 6 O 17 ·3H 2 O (HNbO) nanosheets from KNbO rectangle nanosheets , and the other is dehydration reaction transforming into O-Nb 2 O 5 rectangle nanosheets from HNbO nanosheets. And the {010} facets of O-Nb 2 O 5 crystal are transformed from the {010} facets of HNbO crystal in the ingenious topological reaction. The photoelectric performance of the obtained O-Nb 2 O 5 nanosheets is evaluated by decomposing water to H 2 under 370 nm UV light illumination and measuring the accompanying photocurrent . The photocurrent density is 680 nA·cm − 2 generated by splitting water with O-Nb 2 O 5 nanosheets as photocatalyst , and it is 4.3 times of the contrast sample. The result indicates that the (010) facet of O-Nb 2 O 5 is one of the highest photocatalytic active surfaces and shows high photoelectric conversion efficiency. Thus, the O-Nb 2 O 5 nanosheets dominantly exposed (010) facet have potential applications in photocatalyst and photoelectric nanodevices .
研究领域:
材料科学
·
光催化
·
纳米材料
·
无机化学
·
能源材料
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2023
·
IF 4.4
Xiaodong Wang,Lili Ye,Xiaoyuan Zhang,Zhihe Zhang,Jiuzhong Yang,Long Zhao
Acetaldehyde, ethylene oxide , and vinyl alcohol are three C 2 H 4 O isomers that are ubiquitous in combustion over a wide temperature range. A comprehensive reaction kinetics study has been performed for reactions that occur on the same C 2 H 4 O potential energy surface , mainly including the unimolecular reactions of three C 2 H 4 O isomers and the recombination reaction of CH 3 with HCO. Temperature- and pressure-dependent rate coefficients were updated or newly predicted by performing quantum chemical calculations coupled with RRKM/master equation simulations. The dominance of C C bond fission is reconfirmed for acetaldehyde decomposition at higher temperatures. The negligible contribution of CH 4 + CO channel from usual tight intramolecular H-shift transition state provides indirect evidence for previously reported roaming mechanism that was proposed to explain the observation of CH 4 + CO in acetaldehyde pyrolysis . For ethylene oxide pyrolysis , current experiment and kinetic prediction have a good consistency in branching ratios between the formation of acetaldehyde and vinyl alcohol products. The radicals of CH 3 + HCO can also be directly generated from ethylene oxide through a well-skipping reaction mechanism especially at higher temperatures. For CH 3 + HCO recombination, we highlight the importance of CH 3 CO + H channel that was often overlooked previously. Kinetic simulations show that the incorporation of updated rate coefficients and newly identified channels results in a measurable influence on C2 chemistry , indicating the possibility and necessity of further improvement of core mechanism in combustion kinetic models .
研究领域:
物理化学
·
燃烧化学
·
反应动力学
·
量子化学计算
·
分子反应机制
✓ 已验证
DOI
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2015
·
IF 2.169
Xinghao Lin,Yanming Zhao,Youzhong Dong,Quan Kuang,Zhiyong Liang,Danlin Yan,Xudong Liu
A metaphosphate NaFe(PO 3 ) 3 compound has been obtained by solid state method here. This title compound belongs to the orthorhombic structure with the space group of P 2 1 2 1 2 1 (No. 19) and lattice parameters of a = 14.3390(3) Å, b = 14.3374(2) Å, c = 14.3642(1) Å. Its structure can be described as made up of infinite (PO 3 ) 1− chains connected by FeO 6 octahedra, while the monovalent Na cations are located in the tunnels determined by the connection of PO 4 tetrahedrons and FeO 6 octahedrons. Besides, the morphology, vibrational spectra, magnetic and sodium deinsertion/insertion properties of NaFe(PO 3 ) 3 compound are also presented and discussed here for the first time, which can provide more information about the physicochemical properties of this metaphosphate compound.
研究领域:
无机化学
·
材料科学
·
固体化学
·
电化学
·
能源材料
✓ 已验证
DOI
高影响因子
BULLETIN OF MATERIALS SCIENCE
·
2016
·Vol. 39
·期 1
·187-193
·
IF 0.895
CAO RENPING,QIN ZHENGDONG,JIANG SHENHUA,LIANG AIHUI,LUO ZHIYANG,YU XIAOGUANG
A series of CaNb 2 O 6 : x Sm 3+ (0 ≤
x
≤ 10 mol%) and CaNb 2 O 6 : Sm 3+ , Na + /B 3+ phosphors were synthesized by the solid-state reaction method in air. Their crystal structures and luminescence properties were investigated and analysed, respectively. Host CaNb 2 O 6 emitted blue light with excitation 270 nm. CaNb 2 O 6 : x Sm 3+ phosphors showed a systematically varied hue from blue to white by changing Sm 3+ ion concentration from 0 to 10 mol% with excitation of 270 nm and their chromaticity coordinates were the regions from (0.1665, 0.1767) to (0.2484, 0.2260). Luminescence properties of CaNb 2 O 6 : Sm 3+ phosphor were tuned and improved significantly by codoping B 3+ or Na + ions. Energy transfer between Nb \(_{\mathbf {2}}\textit {O}_{\mathbf {6}}^{\boldsymbol {2-}}\) group and Sm 3+ ion was observed and analysed via luminescence properties. The luminous mechanism was explained by energy level scheme and energy transfer process in CaNb 2 O 6 : Sm 3+ phosphor. The strong excitation band peaking at ∼ 407 nm indicated that the CaNb 2 O 6 : Sm 3+ , Na + /B 3+ phosphor has a potential application in white light-emitting diodes based on near-UV LED chip.
研究领域:
材料科学
·
无机化学
·
发光材料
·
固体物理
·
光电子学
✓ 已验证
DOI
高影响因子
JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2022
·Vol. 59
·期 9
·1561-1572
·
IF 2.035
Ling Jiang,Si-Yu Yan,Jing-Wen Dong,Li-Dan Ye,Yue Cheng,Xiao-He Chu
A series of polysubstituted pyrroles were rapidly synthesized in moderate to good yields via catalyst-free one-pot three-component reaction of 1,3-dicarbonyl compounds with primary amines and nitrostyrenes by using liquid-assisted grinding. This protocol provides several advantages over the conventional chemical synthesis, such as simple work-up procedure, wide substrate scope, short reaction time, and environmental friendliness. Structures of polysubstituted pyrroles were confirmed by 1 H NMR, 13 C NMR, and ESI-MS studies.
研究领域:
有机化学
·
药物化学
·
绿色化学
·
合成方法学
·
杂环化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Lvlv Ji,Lei Zhu,Jianying Wang,Zuofeng Chen
A self-supported copper sulfide (CuS) nanowire array (NWA) of hierarchical and porous structure has been developed on Cu foil via two consecutive liquid-solid reactions at room temperature. The composition, structure and morphology of the as-prepared CuS NWA samples have been systematically investigated by a series of techniques. When applied as cathode for the hydrogen evolution reaction (HER) in neutral solution, the optimized CuS NWA electrode exhibits excellent HER performance with high long-term stability. To achieve current densities of 10 and 100 mA cm −2 , it requires overpotentials of only ∼97 and ∼226 mV, respectively. The excellent catalytic performance of CuS NWA toward HER is attributable to the binder-free electrode construction strategy, the unique porous nanowire array structure, and the small solubility product ( K sp ) value of CuS that guarantees the high catalyst stability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2020
·
IF 3.442
Deqiang Feng,Jie He,Lingcheng Zheng,Wenjun Jiang,Ce Zhang,Long Li,Jian Song,Wei Yao
Developing novel catalysts and catalysis processes are highly attractive in environmental protection and energy utilization. Photocatalysis-Fenton combinational process is an environmentally friendly technology and has broad application prospects. In this work, thin Fe@α-Fe 2 O 3 nanosheets with thickness of 2–5 nm were designed by oxidation of Fe metal nanostructure synthesized using a modified solution reaction method. The nanosheet structure with thin thickness has short diffusion distance for the photogenerated carriers and prolongs the carriers' life. Simultaneously, the presence of Fe can reduce the resistance of system and further promote the transport and transfer of photogenerated carriers from the bulk to the surface, causing less carrier recombination and better photocatalytic performance. What's more, the Fe@α-Fe 2 O 3 composite can induce the Fenton-like reaction to generate active • OH radicals, which significantly improve the degradation rate . The synergistic effect of photocatalysis and Fenton processes makes the system show an enhanced photodegradation performance: 96.5% of RhB is degraded after 60 min visible light irradiation , especially, 84.3% of RhB is degraded within the first 10 min, which are much higher than that of the pure α-Fe 2 O 3 sample. This work demonstrates that the conjunction of photocatalysis and Fenton processes based on the Fe@α-Fe 2 O 3 nanosheets provides a potential application for pollutants degradation.
研究领域:
环境化学
·
材料科学
·
催化化学
·
纳米科技
·
物理化学
✓ 已验证
DOI
高影响因子
Progress in Natural Science-Materials International
·
2019
·Vol. 29
·期 4
·379-383
·
IF 3.31
Yongsheng Fu,Jun Li,Jianguo Li
The effect of CdS content on the photo-induced improvement of hydrogen evolution reaction activity of the Pt/CdS electrocatalyst was investigated. Although the electrons transferred from CdS to Pt in the Pt/CdS electrocatalyst increased with the CdS content under illumination, the electrochemical active surface area of the Pt/CdS electrocatalyst decreased with the CdS content, resulting that the photo-induced improvement of hydrogen evolution reaction activity of the Pt/CdS electrocatalyst decreased with the CdS content.
研究领域:
材料科学
·
催化化学
·
物理化学
·
纳米材料
·
能源化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2017
·Vol. 25
·期 10
·1435-1441
·
IF 1.174
Zhirong Chen,Weitao Yang,Hong Yin,Shenfeng Yuan
The uncatalyzed reaction of p -tolyl isocyanate ( p -TI) with water in N , N -dimethylformamide (DMF) was investigated by high performance liquid chromatography (HPLC). The reactions were carried out at different temperatures from 293 K to 323 K, using various molar ratios of water to p -TI. DMF, as a special amide , was proved to be an efficient catalyst for water–isocyanate reaction. Under the reaction conditions in this study, substituted urea was the only final product observed. An appreciable amount of intermediate p -toluidine was detected. Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time. New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism, instead of a simple second order reaction as usual. Kinetic constants were calculated using the software MATLAB . Furthermore, the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed. The activation energy of each step was also determined.
研究领域:
物理化学
·
有机化学
·
反应动力学
·
高分子化学
·
催化化学
·
分析化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
J. He,X.-H. Lu,Y. Shen,R. Jing,R.-F. Nie,D. Zhou,Q.-H. Xia
Cyclohexanol is an excellent starting material for fuel production, but direct selective hydrogenation of phenol to cyclohexanol under mild conditions is a challenge. Herein we report a catalyst made of Ni nanoparticles supported on high-surface silica, which is highly active for selective formation of cyclohexanol under 1.0 Mpa pressure of hydrogen in aqueous medium without additives. Conversion of 100 mol% and selectivity up to 100% are achieved within 4 h and 1.0 MPa H 2 . Some factors such as the type of the source of silica, the loading of Ni, the reaction temperature and time, the H 2 pressure play important roles in controlling the selective hydrogenation. The generality of the 10%Ni/SiO 2 -1 catalyst for this reaction is demonstrated by selective hydrogenation of other hydroxylated aromatic compounds as well.
研究领域:
催化化学
·
有机合成
·
材料化学
·
绿色化学
·
能源化学
✓ 已验证
DOI
Journal of Renewable Materials
·
2022
·Vol. 11
·期 4
·1731-1743
·
IF 2.115
Hongying Chu,Huabei Li,Xiaoyan Sun,Yaowang Zhang
The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body. Hence, producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands. In this study, flame-retardant rubber seed oil-based plasticize (FRP) was prepared via epoxidation reaction and ring opening addition reactions, which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer. When DOP was replaced with FRP, the torque of PVC blends increased from 11.4 to 18.4 N⋅m, the LOI value increased from 24.3% for PVC-FRP-0% to 33.1% for PVC-FRP-20. The THR value diminished from 39 MJ/m 2 (pertaining to PVC-FRC-0) to 22 MJ/m 2 Tg increased from 23°C to 47°C, the weight loss of plasticized PVC blends significantly reduced from 22.6% to 2.8% in leaching tests. The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.
研究领域:
高分子材料
·
阻燃化学
·
绿色化学
·
生物基材料
·
塑料加工
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）