CHINESE CHEMICAL LETTERS
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2017
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IF 1.932
Muhammad Ammar,Yan Cao,Peng He,Li-Guo Wang,Jia-Qiang Chen,Hui-Quan Li
A set of mono- and bimetallic (Zn-Co) supported ZSM-5 catalysts was first prepared by PEG-additive method. The physicochemical properties of the catalysts were investigated by FTIR, XPS, XRD, N 2 adsorption-desorption measurements, SEM, EDS and NH 3 -TPD techniques. The physicochemical properties showed that the ZnCo 2 O 4 spinel oxide was formed on the ZSM-5 support and provided effectual synergetic effect between Zn and Co species for the bimetallic catalyst. Furthermore, bimetallic supported ZSM-5 catalyst exhibited weak, moderate and strong acidic sites, while the monometallic supported ZSM-5 catalyst showed only weak and moderate or strong acidic sites. Their catalytic performances for thermal decomposition of hexamethylene–1,6–dicarbamate (HDC) to hexamethylene–1,6–diisocyanate (HDI) were then studied. It was found that the bimetallic supported ZSM-5 catalysts, especially Zn-2Co/ZSM-5 catalyst showed excellent catalytic performance due to the good synergetic effect between Co and Zn species, which provided a suitable contribution of acidic sites. HDC conversion of 100% with HDI selectivity of 91.2% and by-products selectivity of 1.3% could be achieved within short reaction time of 2.5 h over Zn-2Co/ZSM-5 catalyst.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2017
·Vol. 93
·期 5
·1347-1358
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IF 3.135
Yu Shen,Fumin Wang,Zongzhuang Han,Xubin Zhang
BACKGROUND ZSM-5 zeolites are of great importance in industrial catalysis. However, the diffusion limitations caused by small pore opening restrict the extent of catalytic conversions over conventional ZSM-5. Many studies have shown that mass transfer in zeolite channels can be improved by controlling the morphology or creating additional mesoporosity. Here, the catalytic performance is further improved by the creation of hollow structure and intracrystalline mesopores in ZSM-5 zeolite. RESULTS The characterization results demonstrated that hollow ZSM-5 with intracrystalline mesopores can be synthesized by using a simple one-step hydrothermal strategy with a commercial gemini-type cationic surfactant containing hydrophilic hydroxyl groups. Compared with the Fe-substituted conventional ZSM-5, the Fe-substituted hollow ZSM-5 with intracrystalline mesopores show remarkably enhanced catalytic performance in the hydroxylation of phenol. About 52.2% conversion of phenol can be obtained with almost 96.8% selectivity to dihydroxybenzenes. The catalytic activity remained almost unchanged after five cycles. CONCLUSION The newly created hollow structure and intracrystalline mesopores in ZSM-5 zeolite showed enhanced catalytic activity and reusability for the hydroxylation of phenol, which is higher than most reported systems. The prepared catalyst is a promising alternative material for the hydroxylation of phenol. © 2017 Society of Chemical Industry
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2016
·Vol. 408
·期 27
·7595-7605
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IF 3.125
Bo Chunmiao,Wang Chaozhan,Wei Yinmao
Immobilized metal affinity chromatography (IMAC) has been widely used for the specific separation of biopolymers. However, leakage of metal ions from IMAC adsorbents is of concern in IMAC. In this study, we designed a novel tridenate bis(5-methyltetrazolium)amine (BMTA) to reduce the leakage of metal ions by improving the affinity to immobilized metal ions. The ligand was bonded onto silica via three-step reaction to prepare a high-performance IMAC stationary phase. The chromatographic behaviors of ribonuclease A, cytochrome c , and lysozyme on the Cu(II)-, Ni(II)-, and Zn(II)-chelated stationary phase were investigated with respect to pH effect and elution with an imidazole gradient. The retention times of these three proteins increased by increasing the pH of the mobile phase but decreased by increasing the concentration of the competitive displacer. The retaining strength of the three proteins on the chelated stationary phase were in the order Cu(II) > Ni(II) > Zn(II). The behavior of these three proteins was consistent with the properties of a typical IMAC. The BMTA ligand exhibited a much stronger affinity for Cu(II) and Ni(II) than iminodiacetic acid (IDA), which is often regarded as a standard tridentate IMAC ligand. Quantum mechanical calculations at the B3LYP/6-31G level were used to image the coordination mode of the protein-metal ions-BMTA complex. In addition, a fused histidine-tagged cecropin b-human epidermal growth factor (CB-EGF) from Escherichia coli crude extract was purified by the Ni(II)-chelated stationary phase, and the purity of the CB-EGF was determined to be at least 90 %. These results suggest that the BMTA ligand may have potential applications in the preparation of therapeutics.
A novel ligand of tridenate bis(5-methyltetrazolium)amine (BMTA) was designed to reduce the leakage of metal ions from the column in immobolized metal affinity chromatography (IMAC).
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JOURNAL OF MOLECULAR LIQUIDS
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2016
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IF 2.74
Jiang Xiao,Yongzhong Jia,Chenglong Shi,Xingquan Wang,Ying Yao,Yan Jing
A novel liquid–liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquids (ILs = [C 6,8,10,12 mim] + [PF 6 ] － ) as extraction solvent and benzo-15-crown-5 (B15C5) as extractant. The effects of the concentration of lithium salt , counter anion of lithium salt, initial pH of aqueous phase, and extraction temperature on the lithium isotopes separation were studied. The maximum single-stage separation factor α of 6 Li/ 7 Li obtained in the present study was 1.038 ± 0.002, indicating the lighter isotope 6 Li was enriched in organic phase while the heavier isotope 7 Li was concentrated in the aqueous phase. The formation of 2:1 complex Li(B15C5) 2 + in the IL phase was determined on the basis of slope analysis method. The large value of the free energy change (− G 0 = 77.87 J mol −1 ) indicated the high separation capability of the lithium isotopes by B15C5/30%CH 3 Cl-70% C 6 mimPF 6 mixture extraction system. Lithium in Li(B15C5) 2 + complex was stripped by 0.5 mol·L −1 HCl solution. The extraction system offers high efficiency, simplicity application prospect to separation lithium isotope separation from LiCl solution.
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ACS Applied Materials & Interfaces
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2016
·
IF 7.145
Wei Zhang,Jingyan Xie,Wei Hou,Yangqing Liu,Yu Zhou,Jun Wang
Supported catalysts are widely studied, and exploring new promising supports is significant to access more applications. In this work, novel copper-containing MOR-type zeolites Cu–MOR were synthesized in a one-pot template-free route and served as efficient supports for vanadium oxide. In the heterogeneous oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) with molecular oxygen (O2) under ambient pressure, the obtained catalyst demonstrated high yield (91.5%) and good reusability. Even under the ambient air pressure, it gave a DFF yield of 72.1%. Structure–activity relationship analysis indicated that the strong interaction between the framework Cu species and the guest V sites accounted for the remarkable performance. This work reveals that the Cu–MOR zeolite uniquely acts as the robust support toward well-performed non-noble metal heterogeneous catalyst for biomass conversion.
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MICROPOROUS AND MESOPOROUS MATERIALS
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2017
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IF 3.615
Yong Zhang,Huiping Zhang,Ying Yan
A heterogeneous catalyst (Cu/ZSM-5) was prepared by a metal-organic chemical vapor deposition (MOCVD) method under nitrogen atmosphere using Cu(acac) 2 as the copper precursor, and further characterized by XRD , AAS , SEM, BET, H 2 -TPR and XPS as well as catalytic activity performance for the oxidation of toluene. N 2 adsorption data revealed that the samples (CVD-4) prepared by MOCVD with calcination at 500 °C for 4 h possessed higher surface areas than that (CVD-BC) not calcined. The results of XPS demonstrated that CVD-4 exhibited higher redox property and more surface oxygen species compared with CVD-BC and IM (Cu/ZSM-5 catalyst prepared by impregnation). In particular, the CVD-4 catalysts prepared by MOCVD with calcinations showed the highest catalytic activity for toluene oxidation with 90% conversion of toluene at 293 °C with the feed concentration of 1000 ppm and GHSV of 15,000 h −1 , which was lower than IM (310 °C). The results of a reaction durability test revealed that the Cu/ZSM-5 catalysts prepared by MOCVD possessed excellent durability for toluene oxidation for 63 h, while the conversion of toluene fell down from 90% to 60% after 48 h over IM catalyst.
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RSC Advances
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2016
·Vol. 6
·期 97
·94976-94988
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IF 3.289
Longfei Liao,Ying Liu,Zengyong Li,Junping Zhuang,Yanbin Zhou,Size Chen
Amino modified Fe3O4@SiO2 (Fe3O4@SiO2–NH2) was used to immobilize Cu2+ and VO2+ for preparing Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalysts. Various technologies had been used for the characteristics of catalysts, such as XRD, XPS, FT-IR, SEM, TEM and VSM. The catalytic performance of Fe3O4@SiO2–NH2–VO2+ in HMF oxidation could be significantly enhanced by the use of Fe3O4@SiO2–NH2–Cu2+ as the co-catalysts. The type of reaction solvents showed a great influence on the oxidation of HMF. The highest HMF conversion reached up to 98.7% at 110 °C in toluene with an optimal 2,5-diformylfuran yield of 85.5%. Moreover, the Fe3O4@SiO2–NH2–Cu2+ and Fe3O4@SiO2–NH2–VO2+ catalyst exhibited great stability and could be readily applied in the next recycle after magnetic separation.
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RSC Advances
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2016
·Vol. 6
·期 84
·80368-80382
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IF 3.289
Yating Shen,Yunlei Zhang,Enwei Zhu,Yao Chen,Pei Jin,Meng Liu,Yongsheng Yan,Chunxiang Li
Herein, hierarchical pore foam catalysts (HPFCs) containing Brønsted–Lewis acidic sites and with hierarchical porous properties were synthesized, and their catalytic performance was applied to convert cellulose into HMF through a one-pot reaction. Sulfated ZrO2 nanostructures (SZs) were synthesized through grafting ZrO2 onto the surface of mesoporous silica nanoparticles, and superacid was further introduced onto the surface of the ZrO2 shells through sulfuric acid treatment and calcination. The representative SZs firstly acted as stabilizers in the synthesis of oil-in-water (O/W) Pickering high internal phase emulsions (Pickering HIPEs). After a subsequent ion-exchange process, Brønsted acidic sites were located on the surface of HPFCs. The resulting HPFCs exhibit advantageous properties for catalysis, such as favorable meso–macro porosity, strongly acidic surfaces, and structural stability. Compared with other catalysts (e.g., one without superacid and mesopores (HPFCs-1) and another (HPFCs-2) without mesopores), HPFCs-3 manifested more efficiently (42%) the production of 5-hydroxymethylfurfural (HMF) from cellulose. This study develops a promising method for the fabrication of specific functional solid catalysts, which can be applied to the value-added conversion of abundant cellulose.
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Nanoscale
·
2016
·Vol. 8
·期 46
·19270-19279
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IF 7.76
Zheng Zhang,Yunsheng Chen,Heng Xu,Yan Wo,Zhen Zhang,Ying Liu,Weijie Su,Daxiang Cui,Yixin Zhang
Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is an alternative therapy for hypertrophic scars (HS), which destroys human hypertrophic scar fibroblasts (HSF). However, the poor permeability of ALA both in HS tissue and HSF significantly restricts the PDT of HS. To overcome these barriers, ALA-loaded ethosomal vesicles (ALA-ES) were developed by a pH gradient active loading method and characterized by morphology, entrapment efficiency (EE) and stability. Results show that prepared ALA-ES are homogenous spherical lamellar vesicles, 53 ± 7 nm in size, 50.6 ± 2.3% in EE and have excellent stability. In vitro transdermal delivery studies through HS tissue were carried out by using Franz diffusion cells. Compared to the traditional ALA hydroalcoholic solution (ALA-HA), ALA-ES achieve higher drug retention in less administration time, and fluorescence microscopy showed that ALA-ES penetrate into the deeper dermis of HS in a shorter time, indicating that ALA-ES can enhance the penetration of ALA into HS. Additionally, ALA-ES was visualized in HS tissue for the first time by transmission electron microscopy (TEM). The irregular and collapsed ALA-ES suggest that they can squeeze through narrow spaces to the target area and release ALA into HS. Taking HSF as the target, the transcellular delivery of ALA-ES into HSF cells was investigated by intracellular protoporphyrin IX (PpIX) accumulation. The efficiency of PDT for HSF cells, including the formation of reactive oxygen species (ROS) and cell apoptosis, were also well investigated. Furthermore, the detailed changes of HSF were observed by TEM. The results strongly indicate that ALA-ES can facilitate ALA penetration into HSF cells, and can cause a higher level of cell apoptosis or necrosis than ALA-HA. ALA-ES with high EE is therefore a promising transdermal delivery system for topical ALA administration and has great potential in ALA-PDT of HS.
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TALANTA
·
2025
·
IF 6.1
Zihan Huang,Hongfeng Lu,Hui Dong,Zhiao Chen,Renwei Lu,Yangguang Zhao,Yanru Du,Yuhan Liu,Yuhan Wu,Maotian Xu,Yanfeng Bi,Yanli Zhou
Pre-designed core-shell metal-organic frameworks (MOFs@MOFs) with customized functionalities can enhance the material properties compared to conventional single MOFs. The porous carbon composites derived from MOFs@MOFs also have excellent functionality due to the presence of multiple metal/metal oxide nanoparticles. This paper synthesized a novel MOFs@MOFs composite (MIL-101(Fe)@Ni-MOF) with a core-shell structure with MIL-101(Fe) as the core and Ni-MOF as the shell. After pyrolysis of the above composite, nitrogen-doped porous carbon (Fe 3 O 4 /Ni@NPC) anchored with Fe 3 O 4 nanoparticles and Ni nanoparticles with synergistic catalytic effects were constructed. Fe 3 O 4 /Ni@NPC exhibited synergistic catalytic effects for the synchronous and ultra-sensitive detection of dopamine (DA) and 5-hydroxytryptamine (5-HT) with a detection limit of 0.165 μM for DA and 0.327 μM for 5-HT. Highly accurate and sensitive target detection was also achieved in experiments with human serum and PC12 cells, which was of great clinical importance.
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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2024
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IF 5.8
Xue-Yu Ren,Jing-Pei Cao,Ming-Wen Ma,Xiao-Yan Zhao
We have created a self-assembly method to synthesize the mesoporous structure (SBA-15 and MCM-48) in micro-ZSM-5 by a seed induced crystallization. The micro/mesoporous MCM-48@Z5 composite display the complement effect of micro/mesopores structure in the aromatic yield and coke deposits during catalytic fast pyrolysis of lignite towards aromatics, compared to SBA-15@Z5. Impressively, the mesoporous MCM-48 from the epitaxial growth of ZSM-5 crystal achieved the high alkyl-substituted aromatics in the upgraded tar. By contrast, the developed mesopores in SBA-15@Z5 composites presented the low content of aromatics owing to insufficient acidity. Moreover, from the analysis of the coke nature and composition deposited on the spent zeolites, it can be found that the coke species possessed the light species ( i.e. , benzene, naphthalene and it’s derivatives) and heavy species ( i.e. , long-chain aliphatics), similarly to the coke species on ZSM-5. The coke growth strongly depends on the polymerization on the surface area during catalytic fast pyrolysis of lignite towards aromatics, despite more mesopores on catalysts.
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NEUROSCIENCE LETTERS
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2025
·
IF 2
Xiao Li,Hui Yang,Ming Qian,Hang Liu,Shuang Zuo,Jin-Chun Liu,Wei-Hong Ge,Lin Zhou
Vincristine (VCR) is a commonly used clinical anti-cancer drug, but it can also induce neurotoxicity and cause vincristine-induced neuropathic pain (VINP). The metabotropic glutamate receptor 5 (mGluR5) within spinal dorsal horn neurons regulates the transmission of pain mediated by glutamate. In this study, we investigated for the first time the role of mGluR5 in the transmission of noxious information in VINP. Expression of mGluR5 protein was significantly increased in the spinal cord from days 6 to 14 after VCR injection. Immunofluorescence double staining showed that mGluR5 colocalized with the neuron-specific marker NeuN. The intrathecal administration of MPEP (a specific antagonist of mGluR5) or DHPG (an agonist of mGluR5) influenced the pain threshold and mGluR5 protein expression in VINP mice. The expression of c-Fos protein was also affected by MPEP. Furthermore, simulated blockade of intracellular mGluR5 site by intrathecal injection of small interfering RNA (siRNA) of the excitatory amino acid transporter 3 (EAAT3) reduced mechanical allodynia and thermal hyperalgesia and suppressed the expression of mGluR5 and c-Fos proteins. The results collectively indicate that mGluR5 site in spinal dorsal horn neurons may be involved in the regulation of intracellular nociceptive signal transmission in VINP, and the expression of c-Fos largely depends on the intracellular mGluR5.
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