JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2023
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IF 2.6
Renjie Xu,Jianhong Gu
The experimental solubility of 2-bromo-5-hydroxypyrazine dissolved in 10 mono-solvents (methanol, ethanol, isopropanol, N,N-dimethylformamide (DMF), n-propanol, acetonitrile, acetone, ethylene glycol (EG), propylene glycol (PG), water) and cosolvent mixtures of methanol + water, ethanol + water, isopropanol + water, and DMF + water was determined by the isothermal saturation method between 278.15 and 323.15 K at 101.2 kPa. The largest solubility was observed in DMF + 2-bromo-5-hydroxypyrazine for mono-solvent systems and in DMF + water for mixed solvent systems. The Jouyban–Acree model (J–A), van’t Hoff–Jouyban–Acree model (V–J–A), and Apelblat–Jouyban–Acree model (A–J–A) were utilized to correlate the 2-bromo-5-hydroxypyrazine solubility in mixtures, and the Apelblat model, van’t Hoff model, λh model, and Jouyban model were used to correlate the 2-bromo-5-hydroxypyrazine solubility in 10 mono-solvents. The preferential solvation of 2-bromo-5-hydroxypyrazine in mixed solvents was researched by calculation of δx1,3. This study presents insights into modulating the 2-bromo-5-hydroxypyrazine crystallization process and in understanding equilibrium behaviors in different solvents.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2023
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IF 5.2
Xinyu Li,Shunyu Han,Jingzhe Xu,Nanzhe Jiang
The synthesis of zeolites from natural aluminosilicate minerals is environmentally sustainable. However, the preparation of nano-ZSM-5 zeolite single crystals via the facile “silica–alumina homologation” of natural clay remains challenging. This paper highlights a novel strategy for the synthesis of defect-free, highly crystalline nano-H-ZSM-5 with a uniform morphology through the kinetically controlled in situ reconstruction of the topology of natural clay within a solid-state-like system. Crystal nucleation and growth were decoupled by aging to control the crystal size. The “homogeneous silica–alumina” property of natural clay was found to be directly inherited by nano-H-ZSM-5 to provide uniformly distributed acidic sites for catalysis. This was demonstrated by methanol-to-propylene conversion, wherein the performance of the obtained crystals was superior to that of commercial ZSM-5. This strategy promotes the development of natural silica–aluminate clay resources and allows the scalable production of high-quality nano-H-ZSM-5 single crystals for heterogeneous catalysis .
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Journal of Oleo Science
·
2019
·
IF 1.208
Zhe Tang,Jianhui Su
A simple solid base catalyst, ammonium aluminum carbonate hydroxide (AACH), was prepared and its structure was characterized by many technologies, including XRD, FT-IR, SEM, BET and Elemental Analysis. The prepared catalyst was used to catalyze the conversion of glucose into 5-hydroxymethylfurfural (HMF) in ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]+Cl–) and dimethyl sulfoxide (DMSO) mixtures. Various reaction conditions, including catalyst loading, reaction temperature, reaction duration and solvent, were investigated. A moderated HMF yield of 52.17 % was obtained at the mild reaction conditions (120°C for 4 h). More importantly, the catalyst could be reused for several times without the loss of its significant catalytic activities. After five reaction runs, a HMF yield about 49.34 % was also obtained.
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APPLIED THERMAL ENGINEERING
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2019
·
IF 4.026
Cheng-Yang Cao,Dan Zhang,Chang-Cheng Liu,Song Lu,He-Ping Zhang
5-AT/Sr(NO 3 ) 2 based composite propellants have been applied in fire extinguishing fields as novel power source for several years due to its high thermal stability and large gas production, but the disadvantage of poor combustion stability still indeed to improve. In this study, the influential mechanism of two common burning modifier, nanosized Copper oxide (nano-CuO) and nanosized Zinc oxide (nano-ZnO), on the thermal behavior and combustion characteristics under high pressure of 5-AT based composite propellant was deeply investigated. Simultaneous thermogravimetric-differential thermal analysis (TG-DTA) have been used to identify the changes in the thermal and kinetic behavior of the catalyzed composite propellant. Thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR) analysis and pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) analysis were employed to characterize the composition of evolved gas in propellant decomposition process. Combined with results of the combustion characteristics measurement conducted on a strand burner (1–5 MPa), different kinds of influential mechanisms of these two catalysts on decomposition process and combustion process under elevated pressure conditions were proposed based on presumed physical combustion model. Outcomes of this study will contribute to the design of 5-aminotetrazole solid propellant with a superior combustion property under high pressure, and promote its application into fire-fighting area.
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APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Shaoxia Wang,Jing Li,Yang Qiu,Xuming Zhuang,Xuran Wu,Jing Jiang
Copper is one of the essential trace elements in human body which plays a vital role in the processes of fundamental physiology. Therefore, analysis and detection of copper ions has attracted tremendous attention. In this paper, an electrochemical sensor was successfully developed based on 5-sulfosalicylic acid modified nanocomposite of molybdenum disulfide nanosheets and oxidized multi-walled carbon nanotubes (SSA/MoS 2 /o-MWCNTs). The nanocomposite was characterized by scanning electron microscopy, transmission electron microscopy , element mapping, X-ray diffraction, Fourier transform infrared spectroscopy , X-ray photoelectron spectroscopy, Raman spectroscopy , and electrochemical measurements. Then, nanocomposite-modified glassy carbon electrode was used for the detection of Cu 2+ . Electrochemical analysis of Cu 2+ was performed by differential pulse voltammetry , and the effects of pH, deposition potential, and deposition time were investigated. The results showed that the peak current increased linearly with increasing Cu 2+ concentration over the range of 0.1–11 μM and a detection limit of 0.057 μM (S/N = 3). Finally, the developed sensor was applied for the analysis of Cu 2+ in lake water and dairy products, and the results were consistent with the results of ICP-MS analysis. Therefore, this work demonstrates that the proposed electrochemical sensor can be easily used for the daily monitoring of Cu 2+ .
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Molecular Catalysis
·
2019
·
IF 2.938
Baole Sang,Jiang Li,Xiqiang Tian,Fulong Yuan,Yujun Zhu
The design of a stable and efficient catalyst is crucial to the creation of high-valued bio-based products, and the catalytic selective oxidation of 5-hydroxymethylfurfural (5-HMF) to 2, 5-furandicarboxylic acid (FDCA) has received increasing attention. Different loadings of Au supported on the graphitized carbon (GC) catalysts ( x wt%Au/GC ( x = 0.7, 1.0, 1.3, 2.0 and 2.7)) were prepared and characterized via ICP-OES, N 2 adsorption-desorption, XRD, FT-IR, TG, XPS and TEM. Results show that 2.0 wt%Au/GC displays 97% selectivity of FDCA and a near 100% conversion of 5-HMF in water under 7 bar O 2 pressure for 6 h at 110 °C in the presence of NaOH, which also exhibits good cycling stability. The surface species of Au 0 are in favor of the formation of FDCA. In this work, different reaction parameters were explored to optimize the reaction condition. The intermediates and the reaction pathways were also proposed on the basis of the formation and degradation of esters via various characterizations.
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JOURNAL OF POROUS MATERIALS
·
2018
·Vol. 25
·期 6
·1587-1595
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IF 1.858
Shen Yu,Wang Fumin,Liu Wei,Zhang Xubin
A series of Fe 3+ containing catalysts were synthesized using ion-exchange technique over hierarchically porous ZSM-5 (M-ZSM-5) and micro-mesoporous composite ZSM-5/MCM-41 (ZSM-5/MCM-41), respectively. The prepared catalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, N 2 adsorption–desorption, UV–Vis spectroscopy, temperature programmed reduction and inductively coupled plasma-optical emission spectroscopy. The characterization results exhibit that the hierarchically porous ZSM-5 was synthesized with intracrystalline mesopores, while the micro-mesoporous composite ZSM-5/MCM-41 was prepared with the well-ordered mesopores. Furthermore, the results also prove that the existence of iron in the catalysts was mainly presented in the form of Fe 3+ ions. Catalytic performances of the samples for phenol hydroxylation were compared by using H 2 O 2 as oxidant. Under the optimized conditions, Fe 3+ ion-exchanged M-ZSM-5 (Fe-M-ZSM-5) shows that a phenol conversion of 42.3% obtained with 92.5% selectivity to dihydroxybenzenes, whereas Fe 3+ ion-exchanged ZSM-5/MCM-41 (Fe-ZSM-5/MCM-41) give 46.2% phenol conversion and 90.1% dihydroxybenzenes selectivity, which are all better than most reported results. The recyclability tests show that Fe-ZSM-5/MCM-41 with ordered mesoporous structure and bigger surface area has better anti-deactivation performance than Fe-M-ZSM-5. The excellent catalytic performances were due to the improved diffusion performance with newly created mesopores and the highly active Fe 3+ species obtained by ion-exchange technique.
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BIORESOURCE TECHNOLOGY
·
2018
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IF 5.807
Zihao Zhang,Hao Cheng,Hao Chen,Kequan Chen,Xiuyang Lu,Pingkai Ouyang,Jie Fu
Modified H-type ZSM-5 (HZSM-5) catalysts were prepared using hexadecyl trimethyl ammonium bromide (CTAB) as mesopore templates to enhance the activity for the catalytic fast pyrolysis of rice straw for aromatics compounds. A certain quantity of CTAB added into the HZSM-5 (HZ) forming hierarchical structure exhibited an improvement in the yield of the aromatics and a decrease in the yield of coke in comparison with that of bare HZ. In contrast, excessive CTAB addition resulted in a decrease in aromatic yield and an increase in coke yield. The effects of crystallinity, textural properties, morphological structure and acidity distribution on the production of aromatic compounds were measured by XRD, BET, TEM and NH 3 -TPD. The good crystallinity, small amount of mesopore formation and highest total acidity discovered in HZ-0.01 (the mole ratio of CTAB/SiO 2 is 0.01) provided the highest aromatic compound yield of 26.8% and the lowest coke yield of 39.2%.
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TALANTA
·
2018
·
IF 4.244
Cui Liu,Qiang Zhang,Nianqi An,Jing Wang,Linlin Zhao,Yan Lu
Detection of the adenosine 5′-triphosphatase (ATPase) activity in lysosome of living cells is of great importance for clinical diagnosis of many related diseases, including cancer. In this work, a new water-soluble polythiophene derivative named ZnPT bearing both quaternary ammonium salt groups and dipicolylamine-Zn 2+ (DPA-Zn 2+ ) complexes in its side chain, was designed and synthesized for this propose. The probe mainly localized to lysosome with good biocompatibility and membrane penetration. The real-time, continuous, direct, and label-free assays were achieved through a fluorescence "turn-on" mode by taking advantages of the reaction specificity of ATPase with ATP and the high binding selectivity of ZnPT toward ATP substrate over its hydrolysis product (ADP). This well designed strategy should provide a facile and effective way for investigating ATPase-relevant biological processes.
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Royal Society Open Science
·
2018
·Vol. 5
·期 3
·
IF 2.504
Yi Yang,Huiping Zhang,Ying Yan
Fe2O3-ZSM-5 catalysts (0.6 wt% Fe load) prepared by metal-organic chemical vapour deposition (MOCVD) method were evaluated in the catalytic wet peroxide oxidation (CWPO) of m-cresol in a batch reactor. The catalysts have a good iron dispersion and small iron crystalline size, and exhibit high stability during reaction. In addition, the kinetics of the reaction were studied and the initial oxidation rate equation was given. Catalysts were first characterized by N2 adsorption–desorption isotherms, scanning electronic microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Results show that extra-framework Fe3+ species (presenting in the form of Fe2O3) are successfully loaded on ZSM-5 supports by MOCVD method. Performances of catalysts were tested and effects of different temperature, stirring rate, catalyst amount on hydrogen peroxide, m-cresol, total organic carbon (TOC) conversion and Fe leaching concentration were studied. Results reveal that catalytic activity increased with higher temperature, faster stirring rate and larger catalyst amount. In all circumstances, m-cresol conversion could reach 99% in 0.5–2.5 h, and the highest TOC removal (80.5%) is obtained after 3 h under conditions of 60°C, 400 r.p.m. and catalyst amount of 2.5 g l−1. The iron-leaching concentrations are less than 1.1 mg l−1 under all conditions. The initial oxidation rate equation −rA0=7.2×1011e−81300/RTCA is obtained for m-cresol degradation with Fe2O3-ZSM-5 catalysts.
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CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2018
·
IF 1.712
Yan Cao,Yafang Chi,Ammar Muhammad,Peng He,liguo Wang,Huiquan Li
A non-phosgene route for the synthesis of hexamethylene-1,6-diisocyanate (HDI) was developed via catalytic decomposition of hexamethylene-1,6-dicarbamate (HDC) over Zn–Co bi-metallic supported ZSM-5 catalyst. The catalyst was characterized by FTIR and XRD analyses. Three solvents dioctyl sebacate (DOS), dibutyl sebacate (DBS) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 ) were investigated and compared; DOS gave better performance. The catalytic performances for thermal decomposition of HDC to HDI using DOS as solvent were then investigated, and the results showed that, under the optimized reaction conditions, i.e. ,10 wt% concentration of HDC in DOS, 250 °C temperature, 60 min reaction time, 83.8% yield of HDI had been achieved over Zn–Co/ZSM-5. Decomposition of the intermediate hexamethylene-1-carbamate-6-isocyanate (HMI) over Zn–Co/ZSM-5 in DOS solvent was further studied and the results indicated that yield of HDI from HMI reached to 69.6% (98.6% HDI selectively) at 270 °C, which further increased the yield of the total HDI (HDI tol ) to as high as 95.0%. Recycling of catalyst showed that HDI and HMI yield slightly decreased, and by-product yield increased after the catalyst was reused for 4 times. At last possible reaction mechanism was proposed.
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ANALYST
·
2018
·Vol. 143
·期 23
·5744-5753
·
IF 3.864
Wei Yang,Xia Wu,Tingting Liu,Ting Wang,Xiaohong Hou
An attractive triazine-based conjugated microporous polymer (TCMP) was fabricated via the Friedel–Crafts reaction and magnetized by a simple reduction co-precipitation method for the first time. The morphology and textural properties of the as-synthesized materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, N2 adsorption measurements, elemental analysis, and magnetic measurements. The resulting magnetic triazine-based conjugated microporous polymer (MTCMP) was introduced as an efficient adsorbent for vortex-assisted magnetic solid phase extraction (MSPE) coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of trace 5-nitroimidazoles (5-NDZs) in environmental water samples. The TCMP has abundant delocalized π-electrons and N-containing triazine that can generate π-interactions, intermolecular hydrogen bonds, and electrostatic interactions with polar 5-NDZs. Extraction parameters affecting the recovery efficiency of five 5-NDZs (metronidazole, ronidazole, secnidazole, tinidazole, and ornidazole), including the amount of the adsorbent, the pH value of the sample, the salting-out effect, the adsorption and elution time, and types and volume of the elution solvents, were investigated. Under the optimal conditions, a wide linear range, acceptable recoveries (ranging from 82.62% to 110.9% with the relative standard deviation lower than 9.58%), and good reproducibility (relative standard deviations less than 8.81% for intra-day and inter-day precision) were obtained. The limits of detection for the five analytes were between 0.012 and 0.035 ng mL−1. The established method is rapid, has high sensitivity and accuracy, and has been successfully applied to the detection of 5-NDZs in real environmental water samples.
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