CATALYSIS LETTERS
·
2013
·Vol. 143
·期 5
·463-468
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IF 2.244
Zhu Anlian,Li Qianqian,Li Lingjun,Wang Jianji
Abstract A series of choline-based ionic liquids (CIL) have been synthesized in this work. The results suggested that both the cations and the anions have significant influences on their properties such as thermostabilities, acidities and their performances for the synthesis of 3,4-dihydro-2(H)-pyrimidinones. The optimized catalytic system based on the CIL [DMEA][HSO 4 ] for the Biginelli reactions benefits from the wide substrates tolerance, benign reaction conditions, easy work-up procedures, and the feasible reusability of the ionic liquid. Graphical Abstract The thermostabilities, acidities, and the catalytic activities for the Biginelli reactions are all follows the sequence of [DMEA][HSO 4 ] > [Choline] [HSO 4 ] > [DMEA][H 2 PO 4 ] > [Choline] [H 2 PO 4 ] .
研究领域:
有机化学
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催化化学
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药物合成
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DOI
高影响因子
Polymer Chemistry
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2021
·Vol. 12
·期 47
·6903-6913
·
IF 5.582
Si Wu,Lei Lei,Yuzheng Xia,Susan Oliver,Xiaonong Chen,Cyrille Boyer,Zhiyong Nie,Shuxian Shi
Multifunctional hybrid particles have been attracting tremendous interest over decades. Herein we demonstrated the functionality of poly(N-isopropylacrylamide) immobilized gold nanoparticles (PNIPAMs-AuNP) as both colorimetric temperature-sensors and reusable temperature-switchable catalysts. The hybrid nanoparticles composed of a gold core (diameter = 14.8 ± 0.2 nm) and a PNIPAM shell (thickness = 2.6 ± 0.2 nm) exhibit reversible color changes and size adjustment in aqueous dispersion upon salt and environment temperature variation. Visual observation or colorimetric monitoring of the PNIPAMs-AuNP dispersion through a UV-vis spectrometer, we were able to detect and calibrate the changes in color between red–purple–red as the environmental temperature changes. The synergetic effect of different types of salt has been systematically investigated. It is observed that the sensitivity of the colorimetric temperature-sensor could be significantly improved by adding salts (NaCl < KCl < MgCl2) or controlling salt concentrations. Moreover, the temperature-switchable PNIPAMs-AuNP hybrid nanoparticles were applied to catalyze the reduction reaction of 4-nitrophenol to 4-aminophenol. The reduction process can be sped-up or slowed-down by controlling the system temperature, which switches the catalytic AuNPs surface on and off as the reversible PNIPAM chains collapse (hydrodynamic size = 41 ± 1 nm) and expand (49 ± 1 nm). Moreover, the switchable catalysts can be recycled through centrifugation and reused. The polymer-engineered core–shell PNIPAMs-AuNP hybrid nanoparticles are promising to enrich the development of temperature-responsive systems such as ambient temperature alarms and smart catalysts.
研究领域:
材料科学
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化学工程
·
生物医学工程
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Wenwen Qiang,Xiang Liu,Teck-Peng Loh
The first example of a heterogeneous catalyst based on hydrotalcite-derived Mg–Al oxides supported iridium (Ir/MgxAlO) for activation of methanol in the synthesis of bis(indolyl)methanes (BIMs) is reported. In this clean and reusable iridium-based catalytic system, a variety of substituted indoles were selectively converted to their corresponding BIMs in moderate to good yields with high tolerance to reducible functional groups by using methanol as a bridging methylene (−CH2−) donor. The high catalytic activity and selectivity of the reaction benefit from the delicate cooperation of redox/acid–base surface sites on this artificially designed multifunctional Ir/MgxAlO catalyst. The overall simplicity, chemoselectivity and sustainability of the catalytic system make this approach a valuable and step-economical tool to construct C–C bond directly from methanol in the synthesis of more complex molecules.
研究领域:
化学
·
催化材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2025
·
IF 3.9
Zuyun Luo,Jiahui Lin,Yangen Lv,Xinze Ye,Shucui Han
Ionic liquids serve as environmentally friendly alternatives to traditional catalysts for biodiesel production. In this work, the sulfonic acid-functionalized ionic liquid [TMG-PS][HSO 4 ] was synthesized via two steps and demonstrated high catalytic efficiency for esterification. The reaction process of myristic acid and methanol was optimized using single-factor experiments and response surface methodology. Specifically, [TMG-PS][HSO 4 ] achieved a high conversion rate of 97.53 % under the reaction conditions: temperature of only 42 °C, time of 5 h, catalyst dosage of 6.0 wt%, and molar ratio of methanol to myristic acid of 12:1. Remarkably, the catalyst displayed excellent stability for ten cycles. Moreover, [TMG-PS][HSO 4 ] also displayed generality and high catalytic activity in catalyzing the reactions of other free fatty acids (FFAs) with methanol to produce biodiesel. Therefore, these results demonstrate that [TMG-PS][HSO 4 ] has significant potential for biodiesel applications.
研究领域:
催化化学
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绿色化学
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能源材料
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应用化学
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生物质能转化
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产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Shucui Han,Jinbei Yang,Hui Huang
In this work, two double-site acidic ionic liquids were synthesized by a two-step method via the reaction of 1,2-bis(diphenylphosphino) ethane (DPhPE) with 1,3-propanesulfonate (PS) to form a DPhPE-PS zwitterion followed by acidification with different acids. The obtained ionic liquids were characterized and further used as catalyst for the esterification of various free fatty acids with methanol to produce biodiesel. The suitable self-solidifying double-site acidic ionic liquid [DPhPE-PS][HSO 4 ] 2 is homogeneous catalytic due to its solubility during the esterification, which is precipitated after reaction. The evaporation of the residual methanol and generated water combines the advantages of homogeneous and heterogeneous catalysts, including their excellent catalytic activity and convenient recovery. [DPhPE-PS][HSO 4 ] 2 exhibits 98.65% of oleic acid conversion under operating appropriate conditions optimized by response surface methodology (catalyst dosage of 6.0 wt%, molar ratio of methanol to oleic acid of 10.0:1, reaction temperature of 60.0 °C, and reaction time of 4.0 h) and keeps outstanding catalytic performance after 9 cycles. Moreover, [DPhPE-PS][HSO 4 ] 2 also displays excellent catalytic activity and good versatility in the esterification of various free fatty acids to biodiesel. Hence, the self-solidifying double-site acidic ionic liquid [DPhPE-PS][HSO 4 ] 2 can be used as an environmentally friendly and efficient catalyst for synthesis of biodiesel via esterification.
研究领域:
化学工程
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催化材料
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能源科学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Shengmiao Zhang,Xiaoxing Fan,Fangning Zhang,Yun Zhu,Jianding Chen
The pristine Fe3O4 nanoparticle (FeNP) is supposed to be a good catalyst of Fenton processes which have shown significant potential for water purification. Herein the magnetic macroporous hydrogel beads, having an open-cell structure, were synthesized by sedimentation polymerization of pristine FeNP stabilized oil-in-water high internal phase emulsions. The effects of the FeNP amount, internal phase fraction, and the costabilizer Tween85 concentration on the structure, such as interconnecting degree, void size, and its distribution of both the surface and inner of the beads, were investigated. With a methyl orange (MO) aqueous solution passing through a chromatography column that was filled with the FeNPs loaded hydrogel beads, the efficiency of these hydrogel beads as catalyst for Fenton reaction to decompose MO in water was tested. The MO was decomposed quickly at the first hour, followed by decomposed gradually in a further 5 h, and the decomposition rate of MO could be up to 99.6% at the end of the test. Moreover, MO decomposition rate remained over 98.2% in six batches which were run in the same beads filled column. The results showed that these FeNPs loaded porous hydrogel beads were reusable and highly efficient supporter for catalysis of Fenton reaction for decomposing organic pollutants in water.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2020
·Vol. 22
·期 15
·2642-2648
·
IF 3.117
Ming-Yu Dou,Xian-Qiang Huang,Guo-Yu Yang
By the combination of Ag-complexes and Keggin POMs, two novel inorganic–organic silver–polyoxometalates hybrids, [Ag3L2(DMSO)2][PW12O40]·4DMSO (1) and [(Ag2L2)2][SiW12O40]·10DMSO·2H2O (2) (L = 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine), were synthesized and characterized. Interestingly, the silver atoms in compound 1 are three-coordinated with the AgNO model; however, the Ag atoms of compound 2 were surrounded by four N atoms of the organic ligands and displayed a distorted tetrahedral configuration. Importantly, compound 1 showed high catalytic activities for the three-component coupling reaction of alkynes and secondary amines along with formaldehyde, which resulted in a series of propargylamine derivatives in higher yields (up to 99%). Furthermore, the Ag–POM catalyst was easily recovered by filtration and reused for three cycles without a significant loss in catalytic activity. A tentative mechanism is also proposed for this transformation.
研究领域:
无机化学
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有机化学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）