Journal of Energy Chemistry
·
2013
·
IF 0
Xiuquan Jia,Jiping Ma,Penghua Che,Fang Lu,Hong Miao,Jin Gao,Jie Xu
Direct conversion of fructose-based carbohydrates to 5-ethoxymethylfurfural (EMF) catalyzed by Lewis acid in ethanol was investigated. It was found that BF 3 ·(Et) 2 O was favorable for 5-hydroxymethylfurfural (HMF) etherification to EMF. BF 3 ·(Et) 2 O combination with AlCl 3 ·6H 2 O with the molar ratio of 1 was an effective catalyst system for synthesis of EMF from fructose-based carbohydrates. 55.0%, 45.4% and 23.9% of EMF yields were obtained from fructose, inulin and sucrose under optimized conditions, respectively.
研究领域:
有机化学
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生物化学
✓ 已验证
DOI
Journal of the American Chemical Society
·
2017
·
IF 13.858
Shuai Xu,Peng Zhou,Zehui Zhang,Changjun Yang,Bingguang Zhang,Kejian Deng,Steven Bottle,Huaiyong Zhu
Selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is one of the key reactions for producing chemical commodities from biomass and their derivatives. The challenge for this reaction is to develop an efficient catalytic process that can be conducted under mild conditions (room temperature and atmospheric pressure, using oxygen molecules in air as the oxidant) and a recyclable catalyst. Herein we report a photocatalyst of cobalt thioporphyrazine (CoPz) dispersed on g-C3N4 (abbreviated as CoPz/g-C3N4), which exhibits excellent catalytic activity toward the selective oxidation of HMF into FDCA under simulated sunlight using oxygen molecules in air as a benign oxidant. For example, an FDCA yield of 96.1% in an aqueous solution at pH = 9.18 is achieved at ambient temperature and air pressure. At lower pH (4.01), the product generated is 2,5-diformylfuran. Hence, it is possible to control the reaction outcome by control of the pH of the reaction system. g-C3N4 itself is not a suitable catalyst for the selective oxidation because under the experimental conditions g-C3N4 generates hydroxyl radicals that initiate processes that oxidize HMF directly to CO2 and H2O. CoPz on the other hand activates O2 to give singlet oxygen (1O2), which more controllably oxidizes HMF to FDCA albeit at a more moderate yield (36.2%). The strong interaction between the CoPz and g-C3N4 in the CoPz/g-C3N4 catalyst is experimentally evidenced, which not only improves accessibility of the CoPz sites and makes the catalyst recyclable but also disables the hydroxyl radical generation by g-C3N4 and promotes 1O2 generation on the CoPz sites, significantly enhancing the catalytic performance. This study demonstrates the potential for efficient non-noble metal photocatalysts for organic transformations driven by sunlight.
研究领域:
化学工程
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催化科学
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环境科学
✓ 已验证
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
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2019
·
IF 3.553
Li-Quan Ren,Tian-Tian Chang,Da-Peng Ren,Ying Zhou,Bang-Ce Ye
Acinetobacter sp. strain LMB-5 can produce a kind of esterase degrading phthalate esters. However, low activity of Est3563 esterase limited its large-scale application. In this study, computer-aided simulation mutagenesis was used to improve the esterase activity with a tightened screening library and enlarged success rate. Two positive mutants, P218R and A242R, were obtained with 2.5 and 2.1 folds higher than the WT Est3563 esterase, with 11.96 ± 0.45 U·mg −1 and 9.90 ± 0.52 U·mg −1 , respectively. With the help of bioinformatics analysis and three-dimensional printing technology, it was found that the mutations could increase the 240–280 residues swing distance and make them deviate from the catalytic pocket. The instability and deviation of these residues on the lid-like structure of the esterase could deteriorate the seal of the binding pocket and expose the active site. Thus, the catalytic efficiency of the mutants became higher. This result demonstrates that the instability and deviation of the lid-like structure could expand the binding pocket of the esterase and enhance the esterase activity.
研究领域:
酶学
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生物化学
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生物技术
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计算生物学
✓ 已验证
DOI
PubMed
高影响因子
Chemical Engineering Journal Advances
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2022
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IF 0
Hengye Li,Xingwei Han,Wenjie Yu,Lin Zhang,Meijie Wei,Zhongxia Wang,Fenying Kong,Wei Wang
Porous organic polymers containing macrocycles are promising adsorbents to remove organic micropollutants from water. However, it is still a big challenge to achieve the balance between economy and performance in real-world application. This study aimed at tackling this challenge by verifying the feasibility of dimethoxypillar[5]arene (P[5]) as a universal knitting crosslinker. Herein, four typical aromatic building blocks were selected and the corresponding P[5] knitted porous polymers with high cost-effectiveness were successfully obtained by a simple Friedel-Crafts reaction with all the yields in excess of 100%. We have demonstrated the significant roles of P[5] content and surface area on the adsorption kinetics and adsorption capacity, respectively. Specially, P[5] knitted 1,3,5-triphenylbenzene (P[5]-TPB) showed the superior adsorption performance among them. The thermodynamic studies certified the spontaneous and exothermic nature, while the mechanism studies revealed that hose-guest and hydrophobic interactions played fundamental roles in the adsorption process. The studies of flow-through adsorption and adsorption at environmentally relevant concentrations further displayed the superior adsorption performance of P[5]-TPB for practical application. The high cost-effectiveness combined with the excellent adsorption properties of P[5]-TPB achieved the balance between economy and performance, demonstrating great potential as promising adsorbent for real-world application. This work paves a way for the synthesis of cost-effective advanced porous polymers with host-guest property for versatile applications.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
INORGANIC CHEMISTRY
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2022
·
IF 5.436
Mingyang Liu,Zhongwen Ouyang,Xiaochen Liu,Jiaojiao Cao,Tongtong Xiao,Zhengcai Xia,Zhenxing Wang
Isolated large-spin Heisenberg antiferromagnetic uniform chain is quite rare. Here, we have successfully synthesized an ideal one-dimensional (1D) S = 5/2 linear-chain antiferromagnet [C2NH8]3[Fe(SO4)3], which crystallizes in a trigonal lattice with the space group R3c. A broad maximum at Tmax = 18 K is observed in the magnetic susceptibility curve. Notably, no long-range magnetic ordering is observed down to 2 K even if the material has a large Curie–Weiss temperature of θCW = −25.5 K. High-field magnetization at 2 K shows a linear increase until saturation at 30 T, and a high-field electron spin resonance (ESR) reveals the absence of a zero-field spin gap. The intrachain interaction J and interchain interaction J′ are determined. Quite a small ratio of J′/J < 2.5 × 10–3 suggests that [C2NH8]3[Fe(SO4)3] behaves as an ideal 1D uniform linear-chain antiferromagnet, in which the magnetic ordering is prevented by the extremely small interchain interaction and quantum fluctuation even for a classical spin of S = 5/2.
研究领域:
物理学
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材料科学
·
磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2020
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IF 8.247
Ning An,Zhuhang Shao,Zhen Guo,Jiao Xin,Yuanyuan He,Liwen Lv,Kefeng Xie,Xiuyan Dong,Yang Zhang,Zhongai Hu
In this work, we select a novel multi-redox poly (1, 5-diaminoanthraquinone) (PDAAQ) as electroactive material and Cetyltrimethylammonium bromide (CTAB) modified graphene oxide (CGO) as conductive substrate. Benefit from the excellent dispersion of CGO in organic polymerization medium and the abundant functional groups on the surface of CGO, 1, 5-diaminoanthraquinone (DAAQ) monomers may covalently graft on the conducting substrates and realize the directional growth of PDAAQ via the in-situ chemical oxidative polymerization. In three-electrode system, the optimization of PDAAQ/CGO electrode exhibits a high specific capacitance of 760 F g −1 at 1 A g −1 and superior electrochemical stability of 90.4% after 10 000 cycles. Most importantly, the electrochemical kinetic behavior of PDAAQ/CGO electrode is studied in detail. The result indicates that the energy storage process of PDAAQ/CGO is a synergistic result of diffusion-controlled process and capacitive effects, and the latter one is dominant. According to the simulation calculation of kinetic model , the capacitive contribution ratio of PDAAQ/CGO can be as high as 80.6% at a scan rate of 50 mV s −1 . Finally, the as-fabricated asymmetric supercapacitor (ASC) can deliver an energy density up to 41.1 W h kg −1 at a power density of 1000 W kg −1 , indicating a great potential application in high performance supercapacitors .
研究领域:
材料科学
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电化学
✓ 已验证
DOI
高影响因子
SOLID STATE SCIENCES
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2019
·
IF 2.155
Yisong Wang,Tao Du,He Jia,Ziyang Qiu,Yanli Song
ZSM-5 zeolite with high aluminum content (Si/Al = 25) was synthesized and then cation-exchanged with alkali metal , alkaline earth metal , transition metal and rare earth metal cations (Li + , Mg 2+ , Ca 2+ , Cu 2+ , Zn 2+ , La 3+ and Ce 3+ ). Crystal structure and physicochemical properties were characterized by XRD , FTIR , TGA/DTG, XRF and nitrogen adsorption-desorption measurement. CO 2 adsorption isotherms of all samples were recorded approximately 0–120 kPa at 0 °C, 30 °C and 60 °C, and they were all successfully fitted by the Toth model. The N 2 adsorption isotherm presented an approximate straight rising line, and it was perfectly fitted by the Langmuir model. In addition, the CO 2 /N 2 adsorption selectivity, Henry's law constant and the working adsorption quantity were calculated by single component CO 2 and N 2 adsorption testing. Transition metal cations Cu 2+ and Zn 2+ type ZSM-5 had the maximum adsorption quantity of 0 °C (70.24 and 74.38 cm 3 /g), and they had the maximum adsorption selectivity under high pressure and adsorption saturation conditions. The adsorption heat of all ion-exchanged samples was lower than Na-ZSM-5, and it had the approximate value at high loadings (in the range of 15.46–17.65 kJ/mol).
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2015
·Vol. 145
·期 4
·1080-1088
·
IF 2.307
Liu Wentao,Wang Yanfang,Li Wei,Yang Yan,Wang Ningning,Song Zhanxin,Xia Xiao-Feng,Wang Haijun
Abstract A variety of polyethylene glycol-400-functionalized dicationic acidic ionic liquids (ILs) (PEG 400 -DAILs) were synthesized and tested in the dehydration of fructose. Among these catalysts, hydrogen sulfate anion-based ILs showed the higher catalytic performance in the conversion of fructose. The highest HMF yield of 96.5 % with 100 % consumption of fructose were obtained after 60 min at 110 °C. The effects of catalyst concentration, reaction time, reaction temperature, and solvents were systematically investigated. In addition, the generality of the catalysts was examined by processing inulin and sucrose to HMF with yield of 71.9 and 52.1 % under certain conditions, respectively. PEG 400 -DAILs possess modified physicochemical properties such as low viscosity, strong hydrophilicity and hydrogen bonding with sugars so as to improve activity for the dehydration of fructose into HMF. The used IL catalyst could be separated and recycled repeatedly without significant loss of catalytic activity. The research emphasizes preparation of the novel catalysts combining polymers with functionalized ILs for conversion of renewable biomass. Graphical abstract
研究领域:
化学工程
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生物质能
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2023
·Vol. 39
·期 6
·1064-1069
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IF 3.1
He Huan,Zou Zhengxi,Hua Weiming,Yue Yinghong,Gao Zi
A series of ZnO-modified cobaltous ion exchanged ZSM-5 catalysts is prepared using incipient wetness impregnation and characterized by X-ray diffraction (XRD), N 2 adsorption, transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DR UV-Vis), X-ray photoelectron spectroscopy (XPS), pyridine-adsorbed Fourier transform infrared (Py-IR) and Raman. Their catalytic performance towards CO 2 -assisted dehydrogenation of ethane to ethylene has been evaluated. The addition of ZnO onto CoZSM-5 obviously improved the yield of ethylene as well as the conversion of CO 2 . The promoting effect is attributed to the good activity of ZnO for the reverse water gas shift (RWGS) reaction, which enhances the coupling between RWGS and ethane dehydrogenation.
研究领域:
催化化学
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化学反应工程
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材料科学
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环境化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2021
·Vol. 40
·期 2
·247-255
·
IF 6
Qian Wang,Huanshun Yin,Yunlei Zhou,Lulu Cao,Zhengkun Yu,Yamin Xu,Shiyun Ai
Comprehensive Summary As a key epigenetic modification, 5-formylcytosine (5fC) controls many important cell functions, such as gene expression and cell differentiation. However, 5fC exists in mammalian tissues and cells with low content, and its structure is highly similar to 5-methylcytosine (5mC), 5-hydroxymethylcytosine (5hmC) and 5-carboxycytosine (5caC), which requires the detection method for detecting 5fC with high sensitivity and specificity. In this experiment, WS 2 /Bi/Bi 2 O 2 CO 3 was used as the photoactive material, 5fC antibody was used as the target molecule recognition reagent, and rolling amplification (RCA) was employed as the signal amplification strategy to construct a novel photoelectrochemical biosensor for detecting 5-formylcytosine deoxynucleotide (5fdCTP). Firstly, WS 2 /Bi/Bi 2 O 2 CO 3 nanocomposite was prepared and characterized, and then modified on the ITO electrode. Then, polyacrylic acid (PAA) was immobilized by electrostatic adsorption, which was employed as the antibody capture reagent based on the covalent reaction of –COOH on PAA with –NH 2 on Ab. Subsequently, 5fdCTP was recognized through immunoreaction, triggering the subsequent rolling circle amplification reaction with the aid of the crosslinker of Zr 4+ . Finally, positive methylene blue (MB) was adsorbed by negative ssDNA, resulting in an increased photoelectric conversion efficiency of WS 2 /Bi/Bi 2 O 2 CO 3 and improved detection sensitivity. The linear range of the PEC biosensor for detecting 5fdCTP was 0.05—100 nmol/L, and the minimum detection concentration was 12.4 pmol/L (S/N = 3). The applicability of this method has been evaluated by studying the influence of Cd 2+ and antibiotic concentration on the 5fC content in the genomic DNA of maize seedlings.
研究领域:
生物化学
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分子生物学
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分析化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 102
·84014-84021
·
IF 3.84
Shurong Wang,Haizhou Lin,Jingping Chen,Yuan Zhao,Bin Ru,Kunzan Qiu,Jinsong Zhou
5-Hydroxymethylfurfural (HMF) is a bio-based platform chemical that may be converted into various chemicals and fuels. In the present study, we developed an advanced low-boiling single-phase reaction system for producing HMF from glucose. It consists of water and 1,2-dimethoxyethane (DMOE) and uses AlCl3 as catalyst. Our results show that introduction of DMOE can substantially enhance HMF production because of the polar aprotic solvent effect provided by DMOE. Under optimal conditions, a high HMF yield (58.56%) was obtained. GC-MS of the liquid-phase products revealed that HMF and furans comprised 80% and ∼90% of the detected products. Formation of liquid-phase products, including furans, oxygenated aliphatics, cyclopenten-1-ones, and pyrans is discussed. Further study of the humins formed during glucose conversion showed the effective inhibition of humin formation by DMOE. The structure of humins was characterized by FTIR spectroscopy. Finally, HMF production from disaccharides (sucrose, maltose and cellobiose) and polysaccharide (cellulose) using the water–DMOE system resulted in good yields, demonstrating that our single-phase water–DMOE solvent system has good potential use in HMF production from glucose and complex carbohydrates.
研究领域:
化学工程
·
生物化工
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Yannan Du,Hongjun Zang,Yimo Feng,Kai Wang,Yaxin Lv,Zhipeng Liu
This paper briefs the emerging strategies for the designing of catalytic systems, which direct conversion of chitin biomass monomer N -acetyl- d -glucosamine (NAG) to 3-acetylamino-5-acetylfuran was studied systemically. Twelve catalysts were investigated, and pyrazine hydrochloride ([Pyz]Cl) ionic liquid exhibited the good performance-achieving 3A5AF with yields of 36.94% from NAG . Further adding boric acid and CaCl 2 , treating at 190 °C for 60 min, the conversion rate of NAG is 100%, and the yield of 3A5AF can be increased to 69.54% in DMA. Furthermore, functional group changes before and after the reaction have been characterized by FTIR, HPLC-MS and 13 C NMR were applied to monitor the reaction process with [Pyz]Cl as the catalyst. The reactive intermediate was clearly detected by these techniques. Accordingly, a possible reaction pathway was proposed. The results of this experiment provide a mild and efficient reaction route for the degradation of biomass, and enrich the theoretical research of quaternary amine catalysts in the conversion of biomass waste into high value-added chemicals.
研究领域:
生物化学
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催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）