ACS Sustainable Chemistry & Engineering
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2019
·
IF 6.97
Huai Liu,Xuejuan Cao,Junnan Wei,Wenlong Jia,Mengzhu Li,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin
It is challenging to effectively convert 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF), a flexible biobased building-block, over non-noble metal catalysts. In this contribution, Mn–Fe oxides were prepared and served as highly active catalysts for the selective oxidation of HMF to DFF. Among Mn–Fe oxides with varied Mn–Fe molar ratios, Mn6Fe1Ox showed the best catalytic activity and offered HMF conversion up to 97% with a DFF selectivity of 98% (110 °C, 5 h, and 1.5 MPa O2). It is revealed that the introduction of α-Fe2O3 resulted in significant enhancement in the amount of catalytic active sites (Mn4+–O2– pairs) and their activity in Mn6Fe1Ox for the dehydrogenation of HMF to DFF. Mn6Fe1Ox also was a robust catalyst that could be successively used at least six times without substantial loss in its catalytic activity. Furthermore, a facile two-step process for the conversion of fructose to DFF with a yield up to 80% was developed by the integration of dehydration and oxidation over Amberlyst-15 and Mn6Fe1Ox, respectively.
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ENERGY & FUELS
·
2019
·
IF 3.021
Binglin Chen,Guizhuan Xu,Chun Chang,Zhangbin Zheng,Dongxiang Wang,Shaohao Zhang,Kai Li,Caihong Zou
The one-pot production of a promising biofuel, 5-ethoxymethylfurfural (EMF) from corn stover with mixed acid as the catalyst, was investigated and optimized by using the response surface methodology. Catalyzed by the mixed acids comprised of 0.1% H2SO4 and 1.0% zeolite USY, a high EMF yield of 23.9% at 210 °C and 125 min can be obtained from corn stover. Meanwhile, the catalytic activity of the zeolite USY had no obvious loss after five recycles. On the basis of the putative reaction pathway, the kinetics modeling for the EMF production directly from corn stover was developed, which coincided with the first-order reaction model. This study provides a promising strategy for EMF preparation from corn stover.
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PETROLEUM SCIENCE AND TECHNOLOGY
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2019
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IF 1.07
Lin Li,Xuwei Liu,Huijing Wang,Chaocheng Zhao,Qiyou Liu,Xiufang Shang
Environmental adaptability and biodegradability of oil pollutants on functional bacteria are two important keys to bioremediation technologies. Pseudomonas sp. LKY-5 revealed strong biological activities in high salinity (3%) and high alkalinity (pH 9.0). N-hexadecane, phenanthrene, pyrene and carbazole could be directly utilized, and inhibited by the presence of DBT. Sulfur compounds and alkanes in No. 0 diesel and FCC diesel were effectively degraded. The concentrations of short chain alkanes were increased significantly after degradation. It can be seen that strain LKY-5 is an excellent bacterial candidate for bioremediation of oil-contaminated sites and sediments.
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高影响因子
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY
·
2018
·Vol. 47
·期 6
·2420-2431
·
IF 5.5
Zhu Zhendong,Li Rongnan,Ma Gongzhen,Bai Wenjing,Fan Xiaoteng,Lv Yinghua,Luo Jun,Zeng Wenxian
Background/Aims: ATP is essential for mammalian sperm to survive and maintain fertilizing capacity. AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. The aims of the present study were to explore the localization of AMPK in goat sperm and to investigate whether and how AMPK regulates sperm functions in vitro. Methods: Sperm were treated with AMPK modulators (AICAR, metformin and Compound C) during incubation. Sperm motility was assessed with a computer-assisted spermatozoa analysis system (CASA). Membrane integrity, acrosome reaction and mitochondrial membrane potentials were detected by SYBR-14/PI, FITC-PNA and JC-1 staining, respectively. And the lactate content, ATP content, AMPK activity, activity of pyruvate kinase (PK) and lactate dehydrogenase (LDH) were also measured with the commercial assay kits. Immunofluorescence staining was used to analyze the distribution of PK, LDH, AMPK and phospho-Thr172-AMPK in sperm. The role of AMPK was further studied during induction of capacitation and acrosome reaction. Results: We found that AMPKα was localized in the entire acrosomal region, the midpiece and the flagellum, while the phospho-Thr172-AMPK was distributed in the head, the midpiece and flagellum. Activation of AMPK by AICAR and metformin significantly improved sperm motility, membrane integrity and acrosome reaction, largely maintained sperm mitochondrial membrane potentials, lactate content and ATP content, and enhanced the activity of AMPK, PK and LDH, whereas inhibition by Compound C triggered the converse effects. Moreover, PK was localized in the acrosomal area and the midpiece, while LDH was distributed in the tail. Induction of capacitation and acrosome reaction led to AMPK phosphorylation. AMPK phosphorylation regulated the activity of energetic enzymes. Conclusion: This study for the first time provides evidence that AMPK governs goat sperm functions through energy metabolism in vitro. This finding will help to improve assisted reproductive techniques in goats and the other species
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PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Chao Xia,Caiyan Yu,Mengmeng Cao,Jinfeng Xia,Danyu Jiang,Guohong Zhou,Dafeng Zhang,Huili Li
In this work, a new Eu and Tb co-doped luminescent compound based on MOF-5, [Zn 4 O(BDC) 3 ], (named as compound 1 ) was successfully synthesized. The structure and morphology characterizations demonstrate that the initial framework of MOF-5 is retained well after co-doping Eu and Tb. The systematic investigations of photoluminescence behaviors reveal that the heat-treated compound 1 (called as compound 1a ) can be utilized as a multi-channel readout luminescent thermometer in emission intensity ratio, decay time ratio, and luminescence color. It simultaneously exhibits the excellent repetitiveness and reversibility under high temperature region from 303 to 473 K. The relative sensitivity of 1.8%/K at 473 K is much higher than the best one of 1.19%/K previously reported for the mixed-lanthanide MOF Tb 0.8 Eu 0.2 BPDA. Until now, such a ratiometric luminescent thermometer with a high sensitivity at the temperature as high as 473 K has been rarely explored.
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高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2018
·
IF 3.849
Yue Zhou,Huiping Zhang,Ying Yan
A series of CuO/ZSM-5 catalysts with different copper loadings were prepared by impregnation (IM) and chemical vapor deposition (CVD) methods, respectively. Their physicochemical properties were investigated by N 2 adsorption/desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectronic spectra (XPS), temperature-programmed reduction by hydrogen (H 2 -TPR) and temperature-programmed desorption of NH 3 (NH 3 -TPD). The XRD and TEM results demonstrated that the crystallite size of the CuO prepared by CVD method was smaller than that by IM, and the XPS results illustrated that the copper specie was mostly in Cu 2+ state and Cu + co-existed. The performance of catalytic oxidation of ethyl acetate was conducted in the fixed-bed reactor based on CuO/ZSM-5 catalysts. The experimental results showed that the preparation method affected the catalytic activity of CuO/ZSM-5; the CVD catalysts exhibited a higher catalytic activity for ethyl acetate oxidation compared with the IM catalysts at the same copper loadings. Ethanol and acetaldehyde are observed to be the intermediate products in the combustion of ethyl acetate over the synthesized catalysts. The relative amounts of acetaldehyde and ethanol are determined by the selectivity of the catalyst toward acetaldehyde production from ethanol. Particularly, the 3 wt% CVD catalyst showed the best catalytic activity for ethyl acetate oxidation with 90% conversion of ethyl acetate at 235 °C, which was much lower than that of the 3 wt% IM catalyst (278 °C), meanwhile, the intermediate products of the 3 wt% CVD for ethyl acetate oxidation were completely oxidized into CO 2 and H 2 O at temperature as low as 288 °C.
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高影响因子
TRANSACTIONS OF TIANJIN UNIVERSITY
·
2018
·Vol. 25
·期 2
·143-151
·
IF 0
Du Jianzeng,Li Yonghong,Miao Zhenyu
Novel Ni/ZnO – HZSM-5 adsorbents were synthesized by incipient wetness impregnation. The Ni/ZnO – HZSM-5 adsorbent can achieve deep desulfurization and olefin aromatization at the same time. Thiophene sulfur was removed from 495 to less than 10 ppm via reactive adsorption desulfurization (RADS). Olefins were also converted into aromatics. HZSM-5 did not only support adsorbents but also cooperated with active Ni sites to catalyze olefins into aromatic hydrocarbons. Aromatization of 1-pentene, 2-pentene, 2-methyl-2-butene, and 1-hexene on adsorbents was investigated. The adsorbents were characterized by the Brunauer–Emmett–Teller, X-ray diffraction, temperature-programmed reduction, and temperature-programmed desorption of ammonia and thermogravimetric analysis. The experimental results showed that strong acids on the adsorbent disappeared after HZSM-5 loaded active metal sites, and almost no coke was generated on adsorbents in RADS.
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ACS Nano
·
2018
·
IF 13.709
Peitao Xiao,Fanxing Bu,Ranran Zhao,Mohamed F. Aly Aboud,Imran Shakir,Yuxi Xu
Synthesis of ultrasmall metal–organic framework (MOF) nanoparticles has been widely recognized as a promising route to greatly enhance their properties but remains a considerable challenge. Herein, we report one facile and effective spatially confined thermal pulverization strategy to successfully transform bulk Co-MOF particles into sub-5 nm nanocrystals encapsulated within N-doped carbon/graphene (NC/G) by using conducting polymer coated Co-MOFs/graphene oxide as precursors. This strategy involves a feasible mechanism: calcination of Co-MOFs at proper temperature in air induces the partial thermal collapse/distortion of the framework, while the uniform coating of a conducting polymer can significantly improve the decomposition temperature and maintain the component stability of Co-MOFs, thus leading to the pulverization of bulk Co-MOF particles into ultrasmall nanocrystals without oxidation. The pulverization of Co-MOFs significantly increases the contact area between Co-MOFs with electrolyte and shortens the electron and ion transport pathway. Therefore, the sub-5 nm ultrasmall MOF nanocrystals-based composites deliver an ultrahigh reversible capacity (1301 mAh g–1 at 0.1 A g–1), extraordinary rate performance (494 mAh g–1 at 40 A g–1), and outstanding cycling stability (98.6% capacity retention at 10 A g–1 after 2000 cycles), which is the best performance achieved in all reported MOF-based anodes for lithium-ion batteries.
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PubMed
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Zhigang Yin,Yuehua Hu,Wei Sun,Chenyang Zhang,Jianyong He,Zhijie Xu,Jingxiang Zou,Changping Guan,Chenhu Zhang,Qingjun Guan,Shangyong Lin,Sultan Ahmed Khoso
A novel compound 4-amino-5-mercapto-1,2,4-triazole was first synthesized, and its selective adsorption mechanism on the surface of chalcopyrite was comprehensively investigated using UV–vis spectra, zeta-potential, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy measurements (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and first principles calculations. The experimental and computational results consistently demonstrated that AMT would chemisorb onto the chalcopyrite surface by the formation of a five-membered chelate ring. The first principles periodic calculations further indicated that AMT would prefer to adsorb onto Cu rather than Fe due to the more negative adsorption energy of AMT on Cu in the chalcopyrite (001) surface, which was further confirmed by the coordination reaction energies of AMT-Cu and AMT-Fe based on the simplified cluster models at a higher accuracy level (UB3LYP/Def2-TZVP). The bench-scale results indicated that the selective index improved significantly when using AMT as a chalcopyrite depressant in Cu−Mo flotation separation.
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2018
·
IF 1.712
Chongwen Jiang,Jundong Zhu,Bing Wang,Lu Li,Hong Zhong
Zirconium doped mesoporous KIT-6 samples with different Si/Zr ratios were synthesized by the direct hydrothermal method. Various characterization techniques confirm that highly distributed ZrO 2 nanoparticles and multi-coordinated Zr 4+ species are incorporated in the mesoporous composites. One-pot synthesis of 5-hydroxymethylfurfura(HMF) from glucose was examined in the presence of Zr-KIT-6(20) the molar ratio of Si to Zr is 20 under aqueous system. The effects of temperature, reaction time, catalyst dosage and biphasic solvent system on the conversion of glucose and the HMF yield were investigated. It was found that the glucose conversion and the HMF yield have been improved from 54.8% to 79.0% and from 19.5% to 34.5% in the biphasic MIBK-water system, respectively. Both the acidity of Zr-KIT-6(20) and the biphasic MIBK-water system are responsible for the improved performance of glucose dehydration to HMF.
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高影响因子
Journal of Energy Chemistry
·
2018
·
IF 3.886
Dan Li,Qiying Liu,Changhui Zhu,Haiyong Wang,Chunhua Cui,Chenguang Wang,Longlong Ma
2,5-dimethyfuran (DMF), which is produced from 5-hydroxymethyfurfural (HMF) by hydrodeoxygenation (HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Selective hydrogenation of HMF into liquid fuel DMF has been widely researched. In this paper, Co 3 O 4 catalyst was prepared by co-precipitation and was reduced at different temperatures to form Co–CoO x catalysts. The characterization of catalysts was tested by XRD , TEM, XPS , TPR, BET and NH 3 -TPD. Co–CoO x possessed a high amount of Co metal and CoO x acidic sites, wherein Co worked as the active hydrogenation sites and CoO x acted as the acid promoter to facilitate the selective HDO of HMF to DMF. The synergistic effect of Co–CoO x is the key for HDO of HMF, obtaining 83.3% of DMF yield at 170 °C, 12 h and the reduction temperature of 400 °C. This method not only saves the catalyst cost, but also promotes the utilization of biomass energy.
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高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 21
·期 14
·3930-3939
·
IF 9.405
Guo Qiu,Chongpin Huang,Xiuliang Sun,Biaohua Chen
Bio-based platform chemical 5-hydroxymethylfurfural (5-HMF) can be converted into large-scale, high value-added compounds generally obtained from petroleum. Hence, developing an efficient catalytic system to transform glucose (a cheap and abundant branch of biomass) into 5-HMF has drawn significant attention. Earlier reports have concentrated on a two-step conversion of glucose to 5-HMF involving glucose isomerization into fructose and subsequent dehydration. In this work, efficient heterogeneous niobium-loaded montmorillonite (Nb-MMT) catalysts containing Lewis and Brønsted acid sites have been synthesized by a readily cation-exchanged synthetic method and were used to convert glucose and showed high selectivity and conversion. An optimum 5-HMF yield of 70.52% with a 99% conversion of glucose was achieved in a biphasic solvent of methyl isobutyl ketone (MIBK)/water at 170 °C for 3 h. The catalytic system also exhibited an excellent activity in the conversion of disaccharides and polysaccharides to 5-HMF with satisfactory yields. In addition, Nb-MMT was effectively reused four times without significant loss of activity. Nb-MMT also featured good catalytic activity and selectivity towards carbohydrate conversion in water. Furthermore, the reaction mechanism for the transformation of glucose to 5-HMF over Nb-MMT was investigated by density functional theory (DFT) calculations, and the results showed that niobium oxyhydroxide species of Nb-MMT played an essential role in glucose conversion, and the catalytic mechanism was a synergetic proton transfer process via hydrogen bonding. This study paves the way for improvements in Nb-containing solid acid catalysts for conversion of carbohydrates.
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