CATALYSIS LETTERS
·
2019
·Vol. 149
·期 6
·1651-1659
·
IF 2.372
Bao Jingxian,Fan Yonghui,Zhang Shuyi,Zhong Liangshu,Wu Minghong,Sun Yuhan
Abstract An atomically economical green protocol for the hydrofunctionalization of olefins to higher aliphatic alcohols with 100% anti-Markovnikov regioselectivity was developed via visible-light photocatalytic coupling. This method employs cheap, readily available and abundant methanol as both the C1 feedstock and the hydrogen source under visible light irradiation over CdS photocatalyst. A wide scope of olefin substrates could be hydrofunctionalized successfully to the corresponding higher alcohols with high selectivity. Besides alcohol, acetone and acetonitrile can also couple with olefins to generate the corresponding hydrofunctionalization products, suggesting promising potential industrial application. Graphical Abstract Hydrofunctionalization of olefins to value-added chemicals with high selectivity was achieved via visible-light photocatalytic cross-coupling.
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Nature Communications
·
2019
·Vol. 10
·期 1
·1-8
·
IF 11.878
Liu Kairui,Hou Guangjin,Mao Jingbo,Xu Zhanwei,Yan Peifang,Li Huixiang,Guo Xinwen,Bai Shi,Zhang Z. Conrad
While numerous single atoms stabilized by support surfaces have been reported, the synthesis of in-situ reduced discrete metal atoms weakly coordinated and stabilized in liquid media is a more challenging goal. We report the genesis of mononuclear electron deficient Pt 1 (0) by reducing H 2 PtCl 6 in liquid polydimethylsiloxane-polyethylene glycol (PDMS-PEG) (Pt 1 @PDMS-PEG). UV–Vis, far-IR, and X-ray photoelectron spectroscopies evidence the reduction of H 2 PtCl 6 . CO infrared, and 195 Pt and 13 C NMR spectroscopies provide strong evidence of Pt 1 (0), existing as a pseudo-octahedral structure of (R 1 OR 2 ) 2 Pt(0)Cl 2 H 2 (R 1 and R 2 are H, C, or Si groups accordingly). The weakly coordinated (R 1 OR 2 ) 2 Pt(0)Cl 2 H 2 structure and electron deficient Pt 1 (0) have been validated by comparing experimental and DFT calculated 195 Pt NMR spectra. The H + in protic state and the Cl − together resemble HCl as the weak coordination. Neutralization by a base causes the formation of Pt nanoparticles. The Pt 1 @PDMS-PEG shows ultrahigh activity in olefin hydrosilylation with excellent terminal adducts selectivity.
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JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 10
·7628-7636
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IF 3.442
Lu Xuegang,Chen Changhao,Wen Xiaoxiang,Han Ping,Jiang Wenfeng,Liang Gongying
Highly charged monodisperse magnetite/polystyrene colloidal particles are successfully synthesized by using a miniemulsion polymerization method. The particles, with high saturation magnetization (M s ≈ 38.6 emu g −1 ), display high sensitivity to the magnetic field and can self-assemble into periodically ordered colloidal structure in aqueous solution, thus diffract light strongly, under magnetic induction. By changing the strength of magnetic field, the position of reflection peaks can be reversibly tuned in the range of 420–720 nm, covering almost the entire visible light range. After adding 1.5 wt.% of acid black 210 into the colloidal suspension, the color saturation and brightness of the colloids are significantly improved. As-prepared magnetically responsive colloidal particles have great potential to be used in color display, biosensors, anti-counterfeiting, camouflage, pigments and dyes.
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APPLIED ORGANOMETALLIC CHEMISTRY
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2019
·Vol. 33
·期 6
·e4924
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IF 3.259
Shuai-Yong Dou,Rui Wang
Eight Dawson-type polyoxometalates were successfully prepared and used in an octanal/air oxidative desulfurization (ODS) system for model oil. Among which, the classical 2:18 polyoxometalate K 6 [α-P 2 W 18 O 62 ]·14H 2 O exhibited the best catalytic performance with a sulfur removal ratio of 99.63%. Then, K 6 [α-P 2 W 18 O 62 ]·14H 2 O was supported on graphene oxide (GO) to afford K 6 P 2 W 18 O 62 /GO using the hydrothermal method. Due to the in situ adsorption of the supported catalysts in the ODS process, the sulfur removal ratio was 96.10% without extraction treatment. Compared with the octanal/air ODS system using pure GO as an adsorbent for the oxidation products, the sulfur removal ratio increased from 89.21 to 96.10%, and the n -octanal/S molar ratio decreased from 24 to 4. To facilitate the recycling of the catalyst and avoid catalyst loss, K 6 [α-P 2 W 18 O 62 ]·14H 2 O was supported on magnetic graphene oxide (mGO) to afford K 6 P 2 W 18 O 62 /mGO. The results showed that the supported catalyst could be easily recovered with the aid of an external magnetic field, while maintaining high catalytic activity during five cycles of reuse with little catalyst loss. Furthermore, all the prepared materials were analyzed by a series of characterizations, and the reaction mechanism of the studied system was proposed through contrast tests and GC-MS characterization analysis.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Tingting Huang,Qingyi Peng,Wenjin Shi,Jundong Xu,Yu Fan
This article proposes a novel sodium dodecylbenzenesulfonate (SDBS)-assisted equilibrium adsorption method for preparing highly dispersed Ni/Al 2 O 3 and Fe-promoted NiFe/Al 2 O 3 thioetherification catalysts. The proposed strategy anchors nickel cations onto the electronegative surface of an Al 2 O 3 support modified by negatively charged DBS − bilayers. As a result, this method achieves highly dispersed Ni nanoparticles without strengthening the metal-support interaction, promoting the reducibility and sulfurization of the supported Ni species. The as-prepared Ni-based catalysts have a smaller size, a higher dispersion of metal nanoparticles, and a greater amount of active metal sulfides than their counterparts prepared by the conventional impregnation method, endowing them with excellent catalytic performance for the highly selective removal of mercaptans. This method provides a new opportunity to prepare highly dispersed metal nanoparticles without a strong metal-support interaction.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Ziyu Gao,Huidong Wang,Yuchen Hu,Jianmin Sun
Multi-functional MOF catalyst with oxidative- and acid- centers showed potential in olefins oxidative carboxylation to cyclic carbonates directly. In this work, a series of bimetallic MnZn-MOF-74 with different molar ratios of Mn and Zn were synthesized successfully through a one-pot facile method. Thoroughly characterization indicated that the existence of Zn regulated the valance state distribution of Mn in the obtained MnZn-MOF-74. Mn 99.3 Zn 0.7 -MOF-74 with the highest ratio of Mn III (61.3 %) performed the most efficient activity for olefin direct tandem oxidative carboxylation reaction using aqueous tert -butyl hydroperoxide oxidant under solvent-free condition of 90 °C, 1.0 MPa CO 2 and 4 h. Mn 99.3 Zn 0.7 -MOF-74 also showed satisfactory versatility and recyclability. Based on the experiments, a feasible mechanism was presented. Thanks to the high ratio of active Mn III as main oxidative center, the coordination unsaturated bimetal Mn and Zn as Lewis-acid sites, O 2– of metal − O as Lewis-base sites and combined effect with Bu 4 NBr cocatalyst, Mn 99.3 Zn 0.7 -MOF-74 presented efficient performance for the direct synthesis of cyclic carbonates from olefins. The metal Zn in MOF can regulate the valance state distribution of Mn and result in efficient catalytic property, presenting a potential avenue for direct oxidative carboxylation reaction of olefins to cyclic carbonates synthesis.
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LANGMUIR
·
2024
·
IF 3.7
Haochuan Lu,Lining Bao,Qingwen Dong,Xu Li,Jinxiang Dong
Branched surfactants exhibit a lower surface tension, excellent low defoaming performance, and better wetting ability compared with linear surfactants, making them promising for applications in industrial cleaning. In this study, 2-hexyl-1-decene (C8 olefin dimer), obtained from the dimerization of 1-octene, was used as the hydrophobe to synthesize branched nonionic surfactants via hydroxylation and ethoxylation. The hydroxylation of the C8 olefin dimer to synthesize 2-hexyldecane-1,2-diol (C8 BD) using H2O2 and HCOOH was investigated systematically. Under the optimal reaction conditions (H2O2/C8 olefin dimer molar ratio: 1.5, HCOOH/C8 olefin dimer molar ratio: 4.0, reaction time: 10 h, reaction temperature: 50 °C), the conversion of the C8 olefin dimer and selectivity toward C8 BD were found to reach 99.96 and 79.89%, respectively. Further, branched nonionic surfactants (C8 BDEn) were synthesized via ethoxylation of C8 BD with ethylene oxide and characterized using FTIR, LCMS, 1H NMR, and 13C NMR techniques. The presence of a tertiary hydroxyl group in C8 BD increases the reactivity of the primary hydroxyl group, leading to a narrower range of products and lower residual substrate content. The physicochemical properties and surface properties of C8 BDEn with different degrees of ethoxylation at various concentrations were investigated and compared with those of commercially available Guerbet alcohol polyoxyethylene ethers (C8 GAEO9 and C6 GAEO9). The results show that, compared with C8 GAEO9 and C6 GAEO9, C8 BDE6 displayed a higher surface activity with a lower equilibrium surface tension (27.14 mN·m–1), superior wettability with a smaller contact angle (39.2°), better emulsification performance with a longer emulsification time of 548 s, and excellent foaming properties (initial foam volume of 11.6 mL). This strategy of utilizing coal-based α-olefins for the synthesis of branched nonionic surfactants presents a route to prepare value-added fine chemicals from coal-based resources.
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DALTON TRANSACTIONS
·
2015
·Vol. 44
·期 40
·17508-17515
·
IF 4.197
Shuhao Qin,Lei Dong,Zhuqi Chen,Sicheng Zhang,Guochuan Yin
In Wacker oxidation and inspired Pd(II)/Cu(II)-catalyzed C–H activations, copper(II) is believed to serve in re-oxidizing of Pd(0) in the catalytic cycle. Herein we report that non-redox metal ions like Sc(III) can promote Wacker-type oxidations even better than Cu(II); both Sc(III) and Cu(II) can greatly promote Pd(II)-catalyzed olefin isomerization in which the redox properties of Cu(II) are not essential, indicating that the Lewis acid properties of Cu(II) can play a significant role in Pd(II)-catalyzed C–H activations in addition to its redox properties. Characterization of catalysts using UV-Vis and NMR indicated that adding Sc(OTf)3 to the acetonitrile solution of Pd(OAc)2 generates a new Pd(II)/Sc(III) bimetallic complex having a diacetate bridge which serves as the key active species for Wacker-type oxidation and olefin isomerization. Linkage of trivalent Sc(III) to the Pd(II) species makes it more electron-deficient, thus facilitating the coordination of olefin to the Pd(II) cation. Due to the improved electron transfer from olefin to the Pd(II) cation, it benefits the nucleophilic attack of water on the olefinic double bond, leading to efficient olefin oxidation. The presence of excess Sc(III) prevents the palladium(0) black formation, which has been rationalized by the formation of the Sc(III)⋯H–Pd(II) intermediate. This intermediate inhibits the reductive elimination of the H–Pd(II) bond, and facilitates the oxygen insertion to form the HOO–Pd(II) intermediate, and thus avoids the formation of the inactive palladium(0) black. The Lewis acid promoted Wacker-type oxidation and olefin isomerization demonstrated here may open up a new opportunity in catalyst design for versatile C–H activations.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2012
·
IF 2.237
Ying Tian,Xuan Meng,Ji-yun Duan,Li Shi
Methanesulfonic acid (MSA) was used as the catalyst to remove trace olefins from aromatics (referred to as oil). The reactions were conducted in a round-bottom flask equipped with a reflux condenser and oil-bath under atmospheric pressure. The influences of the reaction temperature, the mass ratio of MSA to oil, and the reaction time were investigated. The experimental results showed that after a 40 min reaction time at 413 K, the olefins conversion of 89.45% was obtained with a mass ratio of MSA to oil of 6%. The catalyst was reused five times without a reactivation treatment, and the olefins conversion reached 66.02% the fifth time. More importantly, the catalytic mechanism was also proposed in this work. In addition, as MSA is biodegradable, this method represents an environmentally benign route to remove trace olefins from aromatics.
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HYDROMETALLURGY
·
2015
·
IF 1.933
Junlian Wang,Guang Chen,Shengming Xu,Linyan Li
The extraction and separation of heavy rare earths is always one of the most challenging unit operations in hydrometallurgy . Research and development of novel efficient extractant is one way to solve this problem. Organophosphinic acid is a good potential extractant. A new method was established for the synthesis of nonsymmetric dialkylphosphinic acid (NSDAPA) (R′R″POOH, R′ ≠ R″), optimized the synthesizing conditions of the key intermediate mono-alkylphosphinic acid and successfully synthesized three novel extractants ( n -octyl)(2,4,4′-trimethylpentyl) phosphinic acid, ( n -octyl)(cyclohexyl)phosphinic acid and (2,3-dimethylbutyl) (2,4,4′-trimethylpentyl)phosphinic acid. The extraction ability of the novel extractants was investigated. The structure–property relationship and the separation performance for heavy rare earth couples Er/Y, Y/Ho, Yb/Tm and Lu/Yb were evaluated.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Qingshan Zhao,Chan Bai,Wenfeng Zhang,Yang Li,Guoliang Zhang,Fengbao Zhang,Xiaobin Fan
Immobilization of metal complexes on solid supports is an efficient approach to remedy the drawbacks of homogeneous catalysis. In this study, an in situ strategy of synthesis and immobilization of a copper (salen) complex onto graphene oxide (GO) support has been developed. To provide the salen ligands, GO was covalently modified with an aminosilane, followed by condensation with salicylaldehyde. The copper (salen) complex was subsequently synthesized and simultaneously immobilized onto the GO surface with a designed tetrahedral chelate structure. The immobilized copper (salen) complex [Cu(salen)–f–GO] kept the two-dimensional sheetlike character of GO and was demonstrated to be highly effective for the epoxidation of olefins. It could be readily reused for successive twelve times without discernible activity and selectivity deterioration, which displays potential for practical applications.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2013
·
IF 2.206
Ying Tian,Xuan Meng,Li Shi
The novel ionic liquids with an alkane sulfonic acid group were prepared and used for removal of trace olefins from aromatics (referred to as oil). The structures and acidities of the ionic liquids were experimentally characterized and systematically analyzed. The influences of various reaction parameters, such as the stirring speed, viscosities of the ionic liquids, molar fraction of ZnCl2, dosage and type of ionic liquid, reaction temperature, reaction time, and the reusability of the ionic liquid, were investigated. It was found that the ionic liquid 1-(3-sulfopropyl)-3-methylimidazolium bromochlorozincinate ([C3SO3Hmim]Br-ZnCl2) with the molar fraction of ZnCl2 of 0.67 exhibited a better performance for olefin removal. Meanwhile, the experimental results showed that after the reaction had taken place at 373 K for 1 h, olefin conversion of 29.54% was obtained with the mass ratio of IL to oil of 0.2. Even though the reusability of the ionic liquid was not good, the separation of the reaction mixture can be performed by simple decantation.
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