FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Tao Xie,Jing-Pei Cao,Chen Zhu,Xiao-Yan Zhao,Ming Zhao,Yun-Peng Zhao,Xian-Yong Wei
Selectively cleaving the C O bonds in lignin to produce aromatic products are challenging problems. Currently, catalytic hydrogenolysis of C O bonds in lignin requires harsh conditions. Herein, selectively cleaving C O bond of benzyl phenyl ether (BPE) was studied over Pd/AC, Ru/AC and Ni/AC. Among these catalysts, Pd/AC efficiently cleaved C O bond in BPE under super mild conditions (25 °C, 2 h and 0.1 MPa H 2 ). The products were toluene and phenol without hydrogenation of the aromatic ring . The main competitive step of hydrogenolysis and hydrogenation is sensitive to reaction temperature over Pd catalyst. A mild temperature is preferred for hydrogenolysis, since the H species nearby the oxygen atom are more strongly adsorbed than nearby the benzene rings . With the different H-donor solvents, the highest conversion of BPE was obtained in isopropanol. Based on the experiments, the reactions occurred via cleavage of the C aliphatic -O bond in BPE and the synergetic effects between the H from absorbed H 2 on the surface of the Pd and the intermediates radicals of benzyl and phenoxy should be the key points to such an optimum result.
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高影响因子
ACS Nano
·
2019
·
IF 13.903
Qinjie Weng,Xi Hu,Jiahuan Zheng,Fan Xia,Nan Wang,Hongwei Liao,Ying Liu,Dokyoon Kim,Jianan Liu,Fangyuan Li,Qiaojun He,Bo Yang,Chunying Chen,Taeghwan Hyeon,Daishun Ling
Gadolinium-based contrast agents (GBCAs) are widely used for T1-weighted magnetic resonance imaging (MRI) in clinic diagnosis. However, a major drawback of GBCAs is that they can increase the toxicological risk of nephrogenic systemic fibrosis (NSF) in patients with advanced renal dysfunction. Hence, safer alternatives to GBCAs are currently in demand, especially for patients with renal diseases. Here we investigated the potential of polyethylene glycol (PEG)-stabilized iron oxide nanoclusters (IONCs) as biocompatible T1MRI contrast agents and systematically evaluated their NSF-related risk in rats with renal failure. We profiled the distribution, excretion, histopathological alterations, and fibrotic gene expressions after administration of IONCs and GBCAs. Our results showed that, compared with GBCAs, IONCs exhibited dramatically improved biosafety and a much lower risk of causing NSF, suggesting the feasibility of substituting GBCAs with IONCs in clinical MRI diagnosis of patients with renal diseases.
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PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Chen Zhu,Jing-Pei Cao,Xiao-Yan Zhao,Tao Xie,Ming Zhao,Xian-Yong Wei
The synergistic catalysis in the catalytic hydrogenolysis (CH) of lignin and its model compounds over a Ni-Ru/AC bimetallic surface was well established. The Ni-Ru/AC exhibits excellent activity and stability for catalytic hydrogenolysis of lignin and its model compound. The additions of Ru into supported Ni/AC can not only improve the overall reactants conversion, but also modify the product distribution. The apparent activation energy (E a ) of BPE hydrogenolysis over Ni-Ru/AC is measured approximately to be 18.3 kJ/mol. This value is considerably lower than the values measured for monometallic Ni/AC (42.4 kJ/mol). Additionally, the turnover frequency (TOF) of Ni-Ru/AC (62.7 h −1 ) was much higher than that of Ni/AC (5.1 h −1 ). In case of CH of lignin, Ni-Ru/AC gave better total liquid yield and higher relative content of main aromatic monomers . The enhancement in the overall hydrogenolysis activity of reactants over bimetallic Ni-Ru/AC is related to the synergistic effect of Ni and Ru. Various characterization methods (XRD, XPS , TEM-EDS, SEM-EDX and BET) are performed to elucidate the formation of synergistic effect. This synergistic effect could originate from the generation of additional surface active sites, small size of metal particles and high dispersion of metal particles.
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高影响因子
POLYMER SCIENCE SERIES B
·
2019
·Vol. 61
·期 2
·124-131
·
IF 0.907
Guanghong Lin,Xiang Hongping,Xi Lu,Wen Zhixia,Wang Zhaowei,Yu Junwei,Liu Xiaoxuan
Abstract A tricomponent catalyst comprising titanium tetrachloride, triisobutyl aluminum and diphenyl ether is developed for the highly cis -1,4-selective polymerization of isoprene. The influence of the content of diphenyl ether and its complexation order on polymerization, microstructure and performance of polyisoprene are studied. The polyisoprene synthesized presents high monomer conversion (91–99%). With the increasing of diphenyl ether content, intrinsic viscosity and viscosity-average molecular weight of polyisoprene increase. The molar percentage of cis -1,4-unit is almost unaffected by diphenyl ether and different complexation sequence. The polyisoprene reveals comparable T g (–61.31°C) and mechanical strengths (11.14 MPa, 667%) to commercially available LHIR-80 synthesized with neodymium. However, the viscosity and viscosity-average molecular weight of the former are lower than that of the latter, which avails the processability and maintains excellent mechanical properties.
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高影响因子
Jove-Journal of Visualized Experiments
·
2019
·
IF 1.108
Weixiang Guan,Chuang Li,Xiao Chen,Xiao-Ying Lu,Chi-Wing Tsang,Haoquan Hu,Hongxu Qi,Changhai Liang
We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption. The study revealed that HNbWO6 nanosheets were attached on CNTs, with some edges of the nanosheets being bent in shape. The acid strength of the supported Pt catalysts increases in the following order: Pt/CNTs < Pt/5HNbWO6/CNTs < Pt/20HNbMoO6/CNTs < Pt/20HNbWO6/CNTs < Pt/20HTaWO6/CNTs. In addition, the catalytic hydroconversion of lignin-derived model compound: diphenyl ether using the synthesized Pt/20HNbWO6 catalyst has been investigated.
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PubMed
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 47
·22849-22859
·
IF 6.97
Jin Cheng,Qian Zhang,Sisi Fan,Amin Zhang,Bin Liu,Yuping Hong,Jinghui Guo,Daxiang Cui,Jie Song
Inorganic nanoparticles (NPs), particularly iron oxide (IO) and gold (Au) NPs, are widely used in a variety of biomedical applications, such as diagnosis and cancer therapy. As an important component of host defense in organisms, macrophages play a crucial role in responding to foreign substances, such as nanoparticles. Thus, it is of utmost importance to understand the nanotoxicity effects on the immune system by investigating the influences of such nanoparticles. In this study, we found that macrophages can take up large amounts of amphiphilic polymer (PMA)-modified Au and IO NPs, which will induce macrophage cell vacuolization and enhance macrophage polarization. This mechanism is an essential part of the immune response in vivo. In addition, we report that smaller-sized nanoparticles (ca. 4 nm) show more significant effects on the macrophage polarization and caused lysosomal damage compared to larger nanoparticles (ca. 14 nm). Moreover, the amount of NP uptake in macrophages decreases upon trapping the PMA with PEG, resulting in reduced vacuolization and a reduced immune response. We hypothesize that vacuoles are formed in large amounts during NP uptake by macrophages, which enhances the immune response and induces macrophages toward M1 polarization. These findings are potentially useful for disease treatment and understanding the immune response when NPs are used in vitro and in vivo.
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高影响因子
SN Applied Sciences
·
2019
·Vol. 2
·期 1
·1-11
·
IF 0
Li Genrong,Yu Wenqin,Xiao Zhaojing,Long Mei,Tong Lanyan,Qiu Yue
A rapid, sensitive, and practical QuEChERS method coupled with gas chromatography–mass spectrometry was developed for the simultaneous determination of 16 chemical adjuvant residues in samples of fruits (apple, nectarine, grape) and vegetables (tomato, cucumber, spinach). All target compounds were separated in less than 16 min. Samples were extracted with acetonitrile, and the types of extraction salt and cleanup sorbent were optimized. The optimized method was validated by evaluating the linearity, accuracy, precision, and matrix effect. The recoveries of the 16 pesticides adjuvants ranged from 61.2 to 116.3% with relative standard deviations lower than 11.6%. Limits of detection ranged from 0.21 to 3.02 μg/kg, and limits of quantification ranged from 0.71 to 10.07 μg/kg. Finally, the developed method was successfully employed to identify and quantify pesticide adjuvant residues in the analysis of 30 real fruit and vegetable samples.
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RSC Advances
·
2019
·Vol. 9
·期 69
·40546-40552
·
IF 3.049
Zhiming Chen,Jiaojiao Song,Qingpeng Zhu,Zhiguo Li,Renchun Yang
Core–shell magnetic Fe3O4@PVBC–TMT (Fe3O4@polyvinylbenzyl chloride–trithiocyanuric acid) nanoparticles containing trithiocyanuric acid groups were fabricated and employed for the fast removal of heavy metals from an aquatic environment. The morphology, structure and properties of Fe3O4@PVBC–TMT nanoparticles were characterized by a series of modern analytical tools. The adsorption behavior of the Fe3O4@PVBC–TMT nanoparticles for heavy metals ions in aqueous solutions was investigated by batch experiments. The maximum removal capacities of the Fe3O4@PVBC–TMT nanoparticles toward Mn2+, Ni2+, Cu2+, Cd2+ and Pb2+ ions were 127.4, 146.6, 180.5, 311.5, and 528.8 mg g−1, respectively. Importantly, it is found that Pb2+ ions can be completely and quickly removed by the Fe3O4@PVBC–TMT nanoparticles. The equilibrium was established within 6 min, and the removal efficiencies were found to be 99.9%, 99.8% and 99.5% for Pb2+ ions at the initial concentrations of 100 mg L−1, 200 mg L−1 and 300 mg L−1, respectively. It is hoped that the core–shell magnetic Fe3O4@PVBC–TMT nanoparticles may find application in wastewater treatment.
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高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Pengwei Xie,Pengcheng Du,Jiagen Li,Peng Liu
Facile approach was established to fabricate the hybrid cluster bombs of PEGylated chitosan encapsulated doxorubicin (DOX)-loaded superparamagnetic nanoparticles as tumor-specific theranostics for targeted DOX delivery and magnetic resonance (MR) imaging, by simply co-precipitation of poly(ethylene glycol) modified chitosan (CS-PEG), oleylamine modified Fe 3 O 4 (OA-Fe 3 O 4 ) nanoparticles and DOX. In presence of OA-Fe 3 O 4 , the particle size of the DOX/OA-Fe 3 O 4 @CS-PEG cluster bombs decreased to around 80 nm from 300 nm of the DOX/CS-PEG nanoparticles, with high drug-loading capacity (DLC) of 24.3% and saturation magnetization (Ms) of 4.11 emu/g, respectively. The in vitro evaluation results indicated that the blank OA-Fe 3 O 4 @CS-PEG clusters showed excellent cytocompatibility, while the DOX/OA-Fe 3 O 4 @CS-PEG clusters could be uptaken into HepG2 cells to deliver DOX into the cell nuclei with enhanced anti-cancer efficacy in comparison with free DOX. In the tumor intracellular micro-environment, the stimuli-responsive hybrid cluster bombs disassembled and re-self-assembled into the OA-Fe 3 O 4 nanoparticle clusters with higher Ms for MR imaging-guided diagnosis, owing to the tumor-specific DOX release and dissolution of CS-PEG.
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高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Wenjing Song,Shijie Zhou,Shihua Hu,Weikun Lai,Yixin Lian,Jianqiang Wang,Weimin Yang,Meiyu Wang,Peng Wang,Xingmao Jiang
We propose a surface atom engineering strategy to obtain a well-dispersed Co-incorporated MoS2 nanomaterial, which maximizes the Co–Mo–S phase and achieves high activity in hydrodeoxygenation (HDO) of lignin-derived phenolic compounds. It was shown by X-ray diffraction, transmission electron microscopy, Ramanspectroscopy, high-sensitivity low-energy ion scattering, and X-ray photoelectron spectroscopy that plenty of accessible Co–Mo–S phase were generated on the catalyst surface, which could accelerate the hydrodeoxygenation (HDO) reaction. Notably, most of the Co–Mo–S phases were located at the top surface of MoS2, which explained the full deoxygenation performance of the CoMoS catalyst. Moreover, among the diverse lignin-derived oxygenated compounds, phenolic hydroxyl HDO was structure-sensitive relative to diphenyl ether over Co-doped MoS2 catalysts. Effective conversion of mixed phenols to corresponding arenes such as BTX (benzene, toluene, and xylene) with high yield (>85%) and stable recyclability was exhibited by using the CoMoS catalyst with highly dispersed Co–Mo–S phase.
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高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Beili Pang,Shan Lin,Yongtang Shi,Yingying Wang,Yingjie Chen,Shuai Ma,Jianguang Feng,Chunkai Zhang,Liyan Yu,Lifeng Dong
A novel nanocomposite of CoFe 2 O 4 nanoparticles with graphene nanosheet (CoFe 2 O 4 /GN) is prepared as a counter electrode (CE) for dye-sensitized solar cells (DSSCs). The size of CoFe 2 O 4 nanoparticles is about 3 nm, and the influence of CoFe 2 O 4 on the electrochemical properties of graphene is studied. The CoFe 2 O 4 nanoparticles anchored on graphene nanosheets can serve as spacers to prevent graphene aggregations and thereby provide efficient diffusion pathways and more active surface area for electrolyte molecules. Also, the CoFe 2 O 4 nanoparticles with substantial catalytic activity accelerate the reduction of triiodide. Meanwhile the graphene improves charge transfer during the catalytic process. Compared with CoFe 2 O 4 , graphene, and Pt electrodes, the CoFe 2 O 4 /GN electrode displays higher catalytic activity because of its minimal charge transfer resistance. The DSSCs fabricated with CoFe 2 O 4 /GN demonstrate an improved photoelectric conversion efficiency of 9.04% in comparison to Pt electrodes (6.54%). This study suggests that CoFe 2 O 4 /GN can replace expensive Pt electrodes for large-scale fabrication of low cost and high efficiency DSSCs.
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ChemSusChem
·
2015
·Vol. 8
·期 10
·1761-1767
·
IF 7.657
Yi Shao,Qineng Xia,Xiaohui Liu,Guanzhong Lu,Yanqin Wang
Graphical Mild mannered: Under mild conditions (170 °C, 2.5 MPa), Pd/10 %Nb 2 O 5 /SiO 2 is effective for the hydrodeoxygenation reactions of 4-(2-furyl)-3-buten-2-one (the aldol adduct of furfural with acetone), palmitic acid, tristearin, and diphenyl ether (model compounds of vegetable oils, microalgae oils, and lignin) and gives high yields (>94 %) of alkanes with little C C bond cleavage. A simple Pd-loaded Nb 2 O 5 /SiO 2 catalyst was prepared for the hydrodeoxygenation of biomass-related compounds to alkanes under mild conditions. Niobium oxide dispersed in silica (Nb 2 O 5 /SiO 2 ) as the support was prepared by the sol–gel method and characterized by various techniques, including N 2 adsorption, XRD, NH 3 temperature-programmed desorption (TPD), TEM, and energy-dispersive X-ray spectroscopy (EDAX) atomic mapping. The characterization results showed that the niobium oxide species were amorphous and well dispersed in silica. Compared to commercial Nb 2 O 5 , Nb 2 O 5 /SiO 2 has significantly more active niobium oxide species exposed on the surface. Under mild conditions (170 °C, 2.5 MPa), Pd/10 %Nb 2 O 5 /SiO 2 was effective for the hydrodeoxygenation reactions of 4-(2-furyl)-3-buten-2-one (aldol adduct of furfural with acetone), palmitic acid, tristearin, and diphenyl ether (model compounds of microalgae oils, vegetable oils, and lignin), which gave high yields (>94 %) of alkanes with little C C bond cleavage. More importantly, owing to the significant promotion effect of NbO x species on C O bond cleavage and the mild reaction conditions, the C C cleavage was considerably restrained, and the catalyst showed an excellent activity and stability for the hydrodeoxygenation of palmitic acid with almost no decrease in hexadecane yield (94–95 %) in a 150 h time-on-stream test.
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高影响因子
危险品化学品经营许可证（带存储）