CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Da Yang,Dongliang Wang,Huan Liu,Xiaoli Zhao,Yong Lu,Shijun Lai,Ye Liu
The neutral palladium(II) complex bis-[1-(5’-diphenylphosphinothiazol-2’-yl)-imidazolyl] dichloropalladium(II) ( 1A ) ligated by thiazolylimidazolyl-based phosphine ( L1 ) in which thiazolylimidazolyl acted as an S- and N-donor provider with weak coordinating nature, and the ionic complex bis-[1-(5’-diphenylphosphinothiazol-2’-yl)-3-methylimidazolium] dichloropalladium(II) trifluoromethanesulfonate ( 2A ) ligated by thiazolylimidazolium-based phosphine ( L2 ) after quaternization of L1 using methyl trifluoromethanesulphonate were synthesized. It was found that the introduced positive charges and strong electron-withdrawing effect in 2A not only led to changes in the configuration and structural stability of the complex, but also lowered its catalytic performance in carbonylative Sonogashira reactions. These effects reveal the important role of the N-donor in 1A . In addition, as an ionic palladium complex, 2A combined with the room-temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate could be recycled eight times as the catalyst in carbonylative Sonogashira reactions without detectable metal leaching.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2015
·
IF 0.754
Li-Li LIAN,Ting-Xiu GUO,Yu-Qing WU,Li JIN,Da-Wei LOU,Da-Zhi SUN
A rapid analytical method was established for the determination of trace amounts of microcystin (MC-LR) in environmental water samples by using magnetic solid phase extraction (MSPE) coupled with HPLC/UV based on a magnetic bentonite sorbent fabricated by solvothermal synthesis method. Several factors influencing the extraction efficiency of MC-LR, such as sorbent amount, pH condition, sample volume, adsorption and desorption time, and desorption solvent, were investigated and optimized. Under the optimal extraction conditions, the limits of detection and quantification for the method were 0.75 and 1.5 ng L −1 , respectively, which was far below the guideline recommended by the World Health Organisation. The method showed a good linearity ( R 2 = 0.9993) in the concentration ranges of 0.25–250 μg L −1 for MC-LR. The MSPE sorbent was simple in preparation, low cost and magnetizable, and the developed MSPE-HPLC method was suitable for the rapid and sensitive determination of MC-LR in nature water samples.
研究领域:
分析化学
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环境科学
✓ 已验证
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2016
·
IF 1.34
Ai-ling YANG,Shun-pin LI,Yu-jin WANG,Le-le WANG,Xi-chang BAO,Ren-qiang YANG
Cu 2 O@Cu 2 O core-shell nanoparticles (NPs) were prepared by using solution phase strategy. It was found that Cu 2 O@Cu 2 O NPs were easily converted to Cu 2 O@Cu NPs with the help of polyvinylpyrrolidine (PVP) and excessive ascorbic acid (AA) in air at room temperature, which was an interesting phenomenon. The features of the two kinds of NPs were characterized by XRD, TEM and extinction spectra. Cu 2 O@Cu NPs with different shell thicknesses showed wide tunable optical properties for the localized surface plasmon (LSP) in metallic Cu. But Cu 2 O@Cu 2 O NPs did not indicate this feature. FTIR results reveal that Cu + ions on the surface of Cu 2 O shell coordinate with N and O atoms in PVP and are further reduced to metallic Cu by excessive AA and then form a nucleation site on the surface of Cu 2 O nanocrystalline. PVP binds onto different sites to proceed with the reduction utill all the Cu sources in Cu 2 O shell are completely assumed.
研究领域:
纳米材料
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无机化学
·
等离子体学
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胶体化学
·
纳米技术
✓ 已验证
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2015
·
IF 1.178
Xiao-feng WANG,Ri-chu WANG,Chao-qun PENG,Wen-yan SUN,Yue-hua SUN
To solve the problem of drying gelcast green body, the thermoresponsive gel system which contains macromonomer graft chains was used in gelcasting of ZnO. The effects of the amount and length of graft chains macromonomer PIPAAm, the total amount of organic matters, and the solid loading on the rheological properties of suspensions were investigated, and the drying mechanism of gelcast green body was analyzed. The results show that ZnO suspensions with the gel system still display shear-thinning rheological behavior, but its viscosity increases with increasing the addition amount and relative molecular mass of PIPAAm graft chain, and the total organic matter content. The PIPAAm graft chains inhibit or even eliminate the formation of the “dense layer” on the surface of gelcast ZnO green bodies, and accelerate the drying of green bodies. The introduction of PIPAAm graft chains facilitates the shrinkage of the gelcast ZnO green bodies, which is a feasible method to increase the relative density of green bodies.
研究领域:
材料科学
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陶瓷工程
·
流变学
·
高分子化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·
IF 2.628
Jixing Liu,Jian Liu,Zhen Zhao,Weiyu Song,Yuechang Wei,Aijun Duan,Guiyuan Jiang
A series of meso-microporous copper-supporting chabazite molecular sieve (Cu-SAPO-34) catalysts with excellent performance in low-temperature ammonia selective catalytic reduction (NH 3 -SCR) have been synthesized via a one-pot hydrothermal crystallization method. The physicochemical properties of the catalysts were characterized by scanning electron microscopy, transmission electron microscopy , N 2 adsorption-desorption measurements, X-ray diffraction, 27 Al magic angle spinning nuclear magnetic resonance , diffuse reflectance ultraviolet-visible spectroscopy, inductively coupled plasma-atomic emission spectroscopy, X-ray photoelectron spectroscopy , temperature-programmed reduction measurements, and electron paramagnetic resonance analysis. The formation of micro-mesopores in the Cu-SAPO-34 catalysts decreases diffusion resistance and greatly improves the accessibility of reactants to catalytic active sites. The main active sites for NH 3 -SCR reaction are the isolated Cu 2+ species displaced into the ellipsoidal cavity of the Cu-SAPO-34 catalysts.
研究领域:
材料化学
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环境催化
·
多孔材料
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工业催化
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能源与环境科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2016
·Vol. 37
·期 7
·1076-1080
·
IF 2.628
Dongfang Niu,Zhijuan Wu,Lipu Zhang,Rongbin Du,Heng Xu,Xinsheng Zhang
Using 1-butyl-3-methyl-imidazolium bromide (BMIMBr) as the supporting electrolyte and magnesium as the sacrificial anode , a new and highly efficient electrochemically catalytic route was developed for the synthesis of cyclic carbonates from epoxides and CO 2 . Based on the cooperative action of BMIMBr and an electrogenerated magnesium salt obtained under a N 2 atmosphere, CO 2 reacted with a wide range of epoxides to readily generate cyclic carbonates in moderate to excellent yields under mild conditions.
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2015
·Vol. 43
·期 10
·1439-1444
·
IF 0.754
Duo YANG,Dong-Ping YU,Xue-Fang DONG,Ai-Jin SHEN,Gao-Wa JIN,Zhi-Mou GUO,Jing-Yu YAN,Ming-Yang LIU,Xin-Miao LIANG
Thiol-ene click chemistry was applied to immobilize polyacrylamide onto alkenyl-modified silica to prepare a novel stationary phase for hydrophilic interaction liquid chromatography. Polyacrylamide was synthesized by reversible addition-fragmentation chain transfer reaction. Alkenyl functionalities were introduced onto the silica by the reaction of silica with the reaction product of 3-isocyanate opropyl trimethoxy silane, allylamine and pyridine in toluene to obtain alkenyl-modified silica (EUS, E-thiol-ene, U-urea, S-silica). The alkenyl-modified silica was then reacted with polyacrylamide in methanol at 55 °C for 48 h in the presence of 2,2-azo diisobutyl amidine hydrochloride to prepare a novel stationary phase (TE-UPAM, TE-thiol-ene, U-urea, PAM-polyacrylamide), for hydrophilic interaction liquid chromatography. This new stationary phase “TE-UPAM” was characterized by element analysis and infrared spectra, and the results showed that, compared with EUS, the carbon content of TE-UPAM increased and the characteristic peaks of multiple amide existed at 1636 and 1570 cm −1 . The effects of water content, salt concentration and pH of the mobile phase on the retention time of polar compounds were investigated. The results showed that the retention time of polar compounds decreased with the increase of water content. In contrast with acidic polar compounds, the retention time of neutral and basic polar compounds increased with the increase of salt concentration, and the retention time of basic polar compounds decreased with the decrease of pH value in the range of 3.3–4.8. The novel stationary phase behaved better than traditional silica stationary phase in the separation of uridine and bases. In addition, good separation of oligosaccharides by the novel stationary phase was also achieved, indicating great potential in the separation of polar compounds.
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2015
·Vol. 43
·期 10
·1569-1572
·
IF 0.754
Ming-Yan LUO,Bei LÜ,Guo-Bin SHEN,Fei-Fang ZHANG,Bing-Cheng YANG
Electrodialytic eluent generator, one of the key components of ion chromatography system, was fabricated and evaluated. The data achieved indicated that its performance could be comparable to that of commercial one. The maximal operation pressure was over 20 MPa, the generated KOH concentration was up to 100 mM, and the designed usage lifetime was about 354 day (take 8 h working time per day). This device will be helpful to the improvement of domestic instruments of ion chromatography.
研究领域:
分析化学
·
仪器科学与技术
·
分离科学
·
离子色谱技术
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·Vol. 36
·期 10
·1726-1732
·
IF 1.964
Huanhui Chen,Xiaoci Li,Guoqing Zhao,Hongbo Gu,Zhirong Zhu
The side-chain alkylation of toluene represents a novel, environmentally friendly, and low cost route for the production of styrene . However, the yield of styrene produced in this way is currently low, and the mechanism responsible for the side-chain alkylation of toluene is poorly understood. Furthermore, the reason for the higher catalytic efficiency of CsX over NaX and KX remains unclear. In this work, the free radical mechanism of the side-chain alkylation of toluene over basic zeolite X has been elucidated using quantum chemical calculations , together with isotope tracing experiments and the reaction between p -nitrotoluene and methanol. The adsorption isotherm of methanol showed that Cs + ions could block methanol from accessing the β-cage, which is where the side-chain alkylation reaction occurred. Furthermore, the H–D exchange results between toluene and deuterated toluene (C 6 D 5 CD 3 ) showed that CsX was more efficient as a catalyst than KX for the conversion of toluene to the corresponding benzyl radical (C 6 H 5 CH 2 • ). These two results therefore explain the higher catalytic activity of CsX towards side-chain alkylation than KX. Based on the free radical mechanism, the selectivity of styrene could be increased from 17.4% to 59.4% using CO 2 as carrier gas instead of N 2 .
研究领域:
物理化学
·
催化化学
·
材料化学
·
反应机理
·
理论化学
·
能源化学
·
环境化学
✓ 已验证
DOI
高影响因子
PLASMA SCIENCE & TECHNOLOGY
·
2015
·Vol. 17
·期 12
·1066
·
IF 0.579
Zhuoming Xie,Rui Liu,Qianfeng Fang,Tao Zhang,Yan Jiang,Xianping Wang,Changsong Liu
W-(0.2, 0.5, 1.0)wt% ZrC alloys with a relative density above 97.5% were fabricated through the spark plasma sintering (SPS) method. The grain size of W-1.0wt% ZrC is about 2.7 μm, smaller than that of pure W and W-(0.2, 0.5)wt% ZrC. The results indicated that the W-ZrC alloys exhibit higher hardness at room temperature, higher tensile strength at high temperature, and a lower ductile to brittle transition temperature (DBTT) than pure W. The tensile strength and total elongation of W-0.5wt% ZrC alloy at 700 °C is 535 MPa and 24.8%, which are respectively 59% and 114% higher than those of pure W (337 MPa, 11.6%). The DBTT of W-(0.2, 0.5, 1.0)wt% ZrC materials is in the range of 500°C–600°C, which is about 100 °C lower than that of pure W. Based on microstructure analysis, the improved mechanical properties of the W-ZrC alloys were suggested to originate from the enhanced grain boundary cohesion by ZrC capturing the impurity oxygen in tungsten and nano-size ZrC dispersion strengthening.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Pengfei Zhang,Jiang Deng,Jianyong Mao,Haoran Li,Yong Wang
By combination of photocatalysis and organocatalysis, a metal-free system composed of mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) and N -hydroxyphthalimide (NHPI) offers an efficient and environmentally friendly method for the oxidation of alcohols at room temperature. As a wide-band gap semiconductor, mpg-C 3 N 4 absorbs visible light and uses the energy to activate NHPI, resulting in high catalytic activity in the subsequent oxidation of alcohols. Interestingly, the main oxidation product of benzyl alcohol can be tuned from benzoic acid to benzaldehyde by increasing the ratio of mpg-C 3 N 4 in the catalyst system. To further understand the reaction route, electron spin resonance and Fourier transform infrared measurements were carried out, confirming that active oxygen and phthalimide N-oxyl radicals formed in the mpg-C 3 N 4 /NHPI system. Based on these results, a catalytic mechanism for the mpg-C 3 N 4 /NHPI system was proposed. Moreover, this metal-free system also works well for the oxidation of various aromatic alcohols with good selectivity for aldehydes or ketones.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2015
·
IF 1.964
Dong Xie,Qihui He,Yangyang Su,Tongwei Wang,Renfu Xu,Baixing Hu
Catalysts play an important role in oxidative desulfurization, a promising process for producing cleaner fossil fuels for transport. A highly efficient catalyst, Q 4 -H 2 Se IV 3 W 6 , for the oxidative desulfurization of dibenzothiophene (DBT) was reported in 2011. To comprehensively evaluate this catalyst and better understand its recovery, two types of the catalyst were prepared by impregnating Q 4 -H 2 Se IV 3 W 6 on MCM-41 and functionalized MCM-41 materials. In the oxidative desulfurization process catalyzed by these supported catalysts, the conversion of DBT reached 98.7%. The catalytic activities were excellent when Q 4 -H 2 Se IV 3 W 6 was impregnated on functionalized MCM-41. The results showed that the supported catalysts had excellent reusability. In addition, a mechanism for the catalytic oxidative desulfurization was proposed.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）