ACS Applied Nano Materials
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2024
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IF 5.3
Gang Xie,Yiping Hao,Yang Bai,Xiangyang Xu,Lv Xia,Ting Huang,Weichao Du,Jingjie Ge
Nano-plugging agents have become the key to efficiently extracting shale gas, which is a clean energy source. Poly(St-(1-Octene)-EGDMA) was synthesized by emulsion polymerization of 1-octene, styrene (St), and ethylene dimethacrylate (EGDMA). Fourier transform infrared spectroscopy, laser scattering, thermogravimetric analysis, scanning electron microscopy (SEM), pressure transfer experiment, and artificial mud cake plugging experiments were used to characterize poly(St-(1-Octene)-EGDMA). The results indicate that poly(St-(1-Octene)-EGDMA) has a particle size of 38.8 nm. After 16 h at 180 °C, the particle size is 49 nm. Based on thermogravimetric analysis, poly(St-(1-Octene)-EGDMA) can tolerate temperatures up to 394 °C, demonstrating excellent high-temperature stability. The rheology of the drilling fluid remains unaltered by poly(St-(1-octene)-EGDMA). With the addition of 2% poly(St-(1-octene)-EGDMA) water-based drilling fluid, the permeability decreased to 2.4 × 10–3 mD and the blocking rate increased to 50%. Simulations are performed with Ansys Fluent 19.2 to verify the experimental results. The potential plugging mechanism of poly(St-(1-Octene)-EGDMA) as a plugging agent was explored. Shale nanopores and nanofractures are invaded by poly(St-(1-Octene)-EGDMA) under pressure. Shale nanopores and nanofractures are plugged by poly(St-(1-Octene)-EGDMA). In water-based drilling fluids, poly(St-(1-Octene)-EGDMA) has a broad range of applications as a possible nano-plugging agent.
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FUEL
·
2025
·
IF 7.5
Geng Chen,Zexiang Bi,Xu Li,Jinxiang Dong
The industrial utilisation of Fischer–Tropsch synthesis (FTS) products, particularly the valuable C5–C9 linear α-olefins, has been hindered by the high energy-intensive separation of olefins and alkanes with identical carbon numbers. This study presents a comprehensive process integrating the selective dimerisation of linear α-olefins to α-olefin dimers, enabling their separation from paraffins in FTS products. These dimers are subsequently converted into branched-chain aldehyde intermediates through heterogeneous hydroformylation using Rh/C as the catalyst. Notably, optimising the reaction conditions achieved the main product aldehyde of α-olefin dimers with excellent selectivity (up to 86.66 %) at 65 °C, compared to linear α-olefins, which exhibited only 49.31 % selectivity. In-situ IR spectroscopy was used to monitor the entire reaction process. The resulting branched aldehyde intermediates were further transformed into branched acids or branched alcohols through oxidation or reduction reactions, respectively. These products have diverse applications as surfactants, coal flotation agents, and cutting fluid additives. The synthesised compounds were characterised using FT-IR, GC, GC–MS, and NMR. In addition, a comprehensive evaluation of their physicochemical properties was conducted. This study provides a versatile design strategy for developing high-value intermediates from α-olefins in the FTS.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
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IF 8.1
Yuanyuan Cui,Jianmin Sun
The direct oxidative carboxylation of olefins and CO 2 to synthesize cyclic carbonates involves a tandem process of epoxidation and CO 2 cycloaddition reactions. However, designing a multifunctional catalyst for this reaction remains challenging. Herein, a composite catalyst ImBr@UiO-66-Br(Co) was synthesized by post-metallization of Co 2+ and subsequent functionalization with an imidazole ionic liquid (IL), which was used effectively for this reaction. The effects of temperature, CO 2 pressure, catalyst dosage, and reaction time on the direct oxidative carboxylation of olefins to cyclic carbonates were investigated. The results showed that ImBr@UiO-66-Br(Co) exhibited optimal performance in the solvent-free reaction system with styrene (3 mmol), tert -butyl hydroperoxide (6 mmol), and tetrabutylammonium bromide (TBAB, 50 mg) at 80 ℃ under 1 MPa CO 2 for 24 h, achieving a styrene conversion of 90.3 % and styrene carbonate selectivity of 80.7 %. The excellent catalytic activity of ImBr@UiO-66-Br(Co) was attributed to the synergistic interactions of the Lewis acidity Zr 4+ sites, the strong nucleophilicity provided by Br - , the weak base sites from tertiary amine and quaternary ammonium groups in imidazole IL, and the redox-active Co 2+ sites. Additionally, the catalyst was easy to separate and maintained stable activity and selectivity over at least five cycles. Finally, the potential catalytic mechanism for the direct oxidative carboxylation of olefins to cyclic carbonates was proposed.
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Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 32
·21398-21405
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IF 10.7
Yi Yu,Meng Wang,Ying Wu,Hongxia Xi
Covalent organic frameworks (COFs) with permanent porosity, high structural stability and framework modifiability offer unique superiority for heterogeneous catalysis. Herein, we propose an in situ metallization strategy to construct a series of metal-functionalized 2D COFs (M/COFs, M = Co, Ni and Zn). The 2D matrix provides inherent accessible Lewis base sites, along with the introduced metal species acting as Lewis acid sites. These active sites with synergistic effects boost the catalytic CO2 conversion performance of these materials. Our results show that these M/COFs efficiently convert CO2 and olefins into cyclic carbonates through one-pot tandem catalysis. Specifically, Co/COFs achieve nearly complete styrene conversion and 85% yield of styrene carbonate without a co-catalyst at 80 °C and 1 bar. Simulation results further reveal the higher interaction energy of Co/COFs and guests and elucidate the underlying catalytic mechanisms of COF catalysts before and after modification. This work provides both scientific and applicational insights into designing high-performance metal-functionalized materials for optimal tandem catalytic performance.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
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IF 4.1
Xiaohong Wang,Jialian Li,Chen Chen,Xu Li,Lei Liu,Jinxiang Dong
Benzene sulfonate surfactants are crucial anionic surfactants, commonly derived from petrochemical sources. Herein, we present a new method for synthesizing alkyl-tetralin sulfonate anionic surfactants using α-olefins (n-hexene, n-octene, n-decene) and tetralin sourced from the coal chemical industry as raw materials. The three-resulting alkyl-tetralin sulfonates (C6-THNS, C8-THNS and C10-THNS), obtained by alkylation and sulfonation of tetralin were characterized through HPLC, FTIR, LCMS and 1 H NMR techniques. Their surfactant properties were also investigated and compared with commercially applied linear alkylbenzene sulfonate (LAS). We observed that C6 alkyl-tetralin sulfonate (C6-THNS) exhibited smaller critical micelle concentration ( CMC =0.60 mM) and lower equilibrium surface tension ( γ CMC =33.43 mN/m). Similarly, C6-THNS also showed comparable foaming, wetting and emulsifying properties with LAS, which can be used as a substitute for LAS surfactants. This study shows that the synthesized alkyl-tetralin sulfonates is a potential surfactant, providing a route for efficiently using coal-based chemicals to synthesize surfactants.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
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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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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
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IF 3.7
Pengcheng Hu,Jinke Yang,Aonan Lai,Shufeng Zhou
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid (IL) were investigated. The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL. As the water concentration increased to 65 mg·g –1 , the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%, and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201. When the concentration of impurities increased to a critical value, the chloroaluminate IL began to deactivate, leading to a decrease in naphthalene conversion. The critical concentrations for ethanolamine, water, methanol, ether, and diisopentyl sulfide were 33 mg·g –1 , 65 mg·g –1 , 67 mg·g –1 , 87 mg·g –1 , and 123 mg·g –1 , respectively. Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation. The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27 Al NMR spectroscopy. 2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better, but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks. 2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL. With the increase in water concentration, the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid, and the Lewis acid gradually decreased, while the Brønsted acid showed a change of increasing first and then decreasing.
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LANGMUIR
·
2024
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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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PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
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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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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2012
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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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RSC Advances
·
2024
·Vol. 14
·期 18
·12853-12863
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IF 3.9
Hong-Bin Ju,Li-Zhi Zhang,De-Bao Li,Tao Geng,Ya-Jie Jiang,Ya-Kui Wang
In this study, two types of catalysts were prepared by the combination of gemini quaternary ammonium salt with two distinct species of phosphotungstic acid. Catalysts prepared by the Wells–Dawson type of phosphotungstic acid and Keggin-type phosphotungstic acid both exhibited dual-phase catalytic behavior, demonstrating both heterogeneous and homogeneous catalytic activities. In comparison to the catalyst prepared by the Keggin-type phosphotungstic acid, due to the higher size of Wells–Dawson type of phosphotungstic acid, hydrogen bonding could not effectively affect the catalyst prepared by H6P2W18O62. Subsequently, the influential factors on the catalytic reaction were investigated. Through the utilization of techniques such as XPS, FT-IR, Raman spectra and other characterization methods, two distinct structure and reaction mechanisms for these catalysts were elucidated under the influence of hydrogen bonding.
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ACS Catalysis
·
2025
·
IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
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