Journal of Physical Chemistry C
·
2014
·
IF 4.835
Ming Wen,Bo Zhou,Hao Fang,Qingsheng Wu,Shipei Chen
An approach has been explored to highly improve the catalytic activity and stability for methanol oxidation reaction (MOR) by using dominant α-(NiCu)3Pd phase-structural NiCuPd nanoparticles (NPs) as anode catalysts. The NiCuPd alloy NPs are monodispersed with the diameter of ∼10 nm and have been prepared by the reduction of Pd(acac)2, Ni(acac)2, and Cu(acac)2 following alloying growth process. In the Ni–Cu–Pd alloy system, Ni atoms fused in Cu3Pd phase to form α-(NiCu)3Pd phase together with NiCuPd solid solution phase. As Ni concentration gradually enriched, the crystallinity of α-(NiCu)3Pd became higher, while its percentage decreased by one degree. Owing to the synergistic effect between components and facet atom arrangement, the catalytic activity and stability of NiCuPd NPs can be adjusted toward the MOR in alkaline media. The maximized crystallinity of α-(NiCu)3Pd results in the largest catalytic activity. Compared with commercial Pd/C with (111) facets, α-(NiCu)3Pd phase with (117) facets afforded a more open-atom arrangement surface and exhibited the remarkable catalytic activity and stability. Containing maximized crystallinity of α-(NiCu)3Pd, Ni63Cu12Pd25 NP-modified electrode, afforded the highest catalytic activity (333 mA·mg–1) toward the MOR, which is about 2.5 times higher than that of the commercial Pd/C-modified one (145 mA·mg–1). Combining the advantages of high electrochemical activity, stability, and economical effectiveness, the novel phase of α-(NiCu)3Pd has great potential as an anode catalyst for methanol fuel cells.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Weida Shi,Zhihao Jin,Juanjuan Wen,Xianfu Chen,Kaiyun Fu,Xiaowei Da,Minghui Qiu,Yiqun Fan
The development of tight ceramic ultrafiltration membranes for water purification facilitates is challenging because of high fabrication costs and low permeate flux . In this study, a low-energy rapid thermal process (RTP) was comprehensively investigated for fabricating of high-precision, permeable α-alumina tight ultrafiltration membranes. Compared to the conventional thermal process (CTP), RTP offers an ultra-fast heating rate and shorter holding time, effectively mitigating grain growth and pore aggregation. Moreover, the decomposition of organic matter is delayed during RTP, providing a lower interfacial energy that enables direct formation of α-alumina at a low temperature of 750 °C. During a secondary subsequent RTP, the residual phase is fully converted to α-alumina by the in-situ seeding effect. By utilizing RTP, we successfully prepared α-alumina ultrafiltration membranes within 30 min by calcination , with an average pore size of approximately 6 nm, a narrow pore distribution coefficient of 1.12, and high permeance of 219 L −1 ·m −2 ·h −1 ·bar −1 .
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高影响因子
BioDesign Research
·
2024
·
IF 0
Xinyue Gui,Fei Li,Xinyu Cui,Ranran Wu,Dingyu Liu,Chunling Ma,Lijuan Ma,Huifeng Jiang,Chun You,Zhiguang Zhu
Terpenoids of substantial industrial interest are mainly obtained through direct extraction from plant sources. Recently, microbial cell factories or in vitro enzymatic biosystems have emerged as promising alternatives for terpenoid production. Here, we report a route for the synthesis of α-farnesene based on an in vitro enzyme cascade reaction using methanol as an inexpensive and renewable C1 substrate. Thirteen biocatalytic reactions divided into 2 modules were optimized and coupled to achieve methanol-to-α-farnesene conversion via integration with natural thylakoid membranes as a green energy engine. This in vitro enzymatic biosystem driven by light enabled the production of 1.43 and 2.40 mg liter−1 α-farnesene using methanol and the intermediate glycolaldehyde as substrates, respectively. This work could provide a promising strategy for developing light-powered in vitro biosynthetic platforms to produce more natural compounds synthesized from C1 substrates.
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AUSTRALIAN JOURNAL OF CHEMISTRY
·
2023
·Vol. 76
·期 11
·774-784
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IF 1.1
Fan-Ming Yang,Xi-Da Li
Rod-like porous α-Fe2O3 was synthesized by static hydrothermal treatment at 160°C and used as a symmetric supercapacitor. The phase information, structure, morphology, valence state and composition of the prepared sample were characterized using X-ray diffraction, infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption. The results show that the prepared α-Fe2O3 is a rod-like porous material dominated by mesopores. Moreover, the α-Fe2O3 is a hexagonal single crystal with [FeO6] octahedrons and the interplanar crystal spacings are large enough for electrolyte ion diffusion. In both KOH and Na2SO4 electrolytes, the α-Fe2O3 sample displays good pseudocapacitance performance. However, the specific discharge capacity and energy density in KOH are larger than in Na2SO4. In 1molL–1 of KOH, remarkable capacities of 139 and 35.5Fg–1 are obtained and an energy density of 3.91 and 1.01Whkg–1 is achieved at 1 and 20Ag–1 respectively. After 10000 cycles, 87.7% of the specific capacitance is still retained at 1Ag–1. The good capacitance properties may attributed to the rod-like porous structure and large interplanar spacing, which provide good ion insertion–exit paths, enough oxidation–reduction active sites and a fast ion transfer velocity.
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高影响因子
Sustainable Chemistry and Pharmacy
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2024
·
IF 5.5
Wei Yang,Jiaqi Liu,Bingbing Wang,Xiaohui Xu,Zhong Sun
A heterogeneous copper-catalyzed dioxygenation of alkenes with N -hydroxyphthalimide (NHPI) is described, providing concise access to α -oxygenated ketones under air atmosphere without the addition of any extra additives. The heterogeneous catalyst consists of copper and bionic material polydopamine (CuCl 2 @PDA), which has nontoxic, stable, cheap and recyclable characters. The catalyst can be recycled and reused at least 7 times. This reaction shows mild and operationally simple conditions, high efficiency, good substrate scope, excellent functional group compatibility, green and sustainable virtues.
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高影响因子
FITOTERAPIA
·
2019
·
IF 2.431
Xue Li,Ling-Juan Zhu,Jin-Peng Chen,Chen-Yu Shi,Li-Ting Niu,Xue Zhang,Xin-Sheng Yao
One new flavanonol , demethylmatteucinol ( 1 ), and nine new flavanone glucoside derivatives, matteflavosides H-J ( 2–4 ) and matteuinterates A-F ( 5 – 10 ), were isolated from the rhizomes of Matteuccia intermedia C.Chr., along with 21 known flavanones ( 11 − 31 ). Notably, all of them contain C -methylation in the A-ring. The structures of the compounds were elucidated by spectroscopic methods and chemical derivatization. The α -glycosidase inhibition assay indicated that compounds 12 – 17 showed potent inhibitory activity with IC 50 values of 12.4–69.7 μM, which suggested their hypoglycemic effect.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Xiaohui Fu,Zheng Li,Min Lin,Jing Sun,Zhibo Li
A series of N -alkylated glycine and l -alanine bearing oligoethylene glycol (OEG) and benzyl side chains, i.e., N -(4-oligoethylene glycol)benzyl glycine and N -(4-oligoethylene glycol)benzyl alanine (NMe(OEt) x OBnG and NMe(OEt) x OBnA, x = 1–3), have been readily synthesized via schiff base and reductive amination reactions. The successful ring opening polymerization (ROP) of N -substituted glycine N -carboxyanhydrides (NCA) results in three types of peptoid oligomers (PNMe(OEt) x OBnG, x = 1–3). Depending on the length of OEG side chains, PNMe(OEt) x OBnG show different solubility in water. Particularly, the as-prepared oligomers containing three ethylene glycol units (PNMe(OEt) 3 OBnG) display interesting thermoresponsive aggregation behaviors in water. DSC results reveal that all the oligomers show crystalline behaviors with melting temperatures decreasing as the OEG side chain length is increased. Both live-dead and MTT assays indicate low cytotoxicity of PNMe(OEt) 2 OBnG and PNMe(OEt) 3 OBnG toward HeLa cells, comparable to benchmark PEG. Concerning thermoresponsive and crystalline properties, the as-prepared peptoid oligomers are potentially promising building blocks for stimuli-responsive bioinspired materials and hierarchical self-assembly.
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高影响因子
Chemical Engineering and Processing-Process Intensification
·
2020
·
IF 3.731
Lan Jiang,Guang-Wen Chu,Ya-Zhao Liu,Wei Liu,Li-Xiong Wen,Yong Luo
A rotating packed bed (RPB) reactor with excellent mass transfer performance can be applied for catalytic reactions. However, the structure of catalyst particles randomly inside the rotor of the RPB reactor was easily deformed under the centrifugal field. In this work, a cordierite (COR) monolithic catalyst with high mechanical strength was prepared, aiming to be used in the RPB reactor for hydrogenation. The acid pretreatment and Al 2 O 3 coating were employed to increase the specific surface area of COR substrate. Active component palladium (Pd) was deposited on Al 2 O 3 /COR. Hydrogenation of α-methylstyrene (AMS) was selected as a model reaction for the RPB reactor with the above Pd/Al 2 O 3 /COR. Experimental results show that the space time yield (STY) in the RPB reactor was effectually enhanced 9.2 times higher than that in the fixed bed reactor at the operation conditions of 30 °C and 0.2 MPa, which shows potential prospects of the RPB reactor with Pd/Al 2 O 3 /COR monolithic catalyst for the process intensification of catalytic reaction.
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高影响因子
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
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2020
·
IF 3.391
Lin Yin,Shanshan Fu,Roujun Wu,Shuyue Wei,Juzhen Yi,Li-Ming Zhang,Liqun Yang
A neutral tea polysaccharide (TPSN) was isolated from green tea. Gas chromatography analysis showed that TPSN was composed of d -glucose, l -arabinose and d -galactose residues at a molar ratio of 90.0: 9.1: 0.9. The weight-averaged molecular weight of TPSN was determined as about 2.0 × 10 5 g mol −1 using static light scattering analysis. The result of nuclear magnetic resonance (NMR) spectroscopy indicated that TPSN and water-soluble starch had similar structures. TPSN exhibited inhibitory activity towards α-amylase through the noncompetitive inhibition mechanism, but the tertiary structure of α-amylase related to enzymatic activity , analyzed using circular dichroism spectroscopy, was not affected by TPSN. Meanwhile, TPSN exhibited hydrolysis properties catalyzed by α-amylase. Molecular docking analysis revealed that the various behaviors of TPSN to α-amylase could be attributed to that the different chain segments of TPSN combined with different amino acid residues of α-amylase.
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高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Fu He,Wencheng Ma,Dan Zhong,Yixing Yuan
The pipe deposits from water distribution network are iron-wastes, which could be used as a catalyst of advanced oxidation processes (AOPs). This paper prepared one main composition (α-FeOOH) of pipe deposits and compared the difference of chloramphenicol (CAP) degradation by α-FeOOH-activated hydrogen peroxide/persulfate and α-FeOOH-activated hydrogen peroxide/peroxymonosulfate with hydroxylamine assistance. Several key affecting factors were investigated. The results revealed that the double-oxidant system has a synergy effect in CAP degradation process. The hydroxyl radicals were identified as the predominant radicals in two different degradation processes via electron paramagnetic resonance (EPR) technique. The possible degradation pathways and products were confirmed by liquid chromatography-mass spectrometry (LC-MS). This study provided a theoretic research for pollutant removal by taking full advantage of pipe deposits and advance the development of water quality security in water distribution network in future.
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高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 19
·2705-2712
·
IF 3.304
Liangfei Ouyang,Tengfei Zheng,Liang Shen
The application of in situ powder X-ray diffraction (XRD) to monitor the polymorphic transformation and crystallization of glycine from an ionic liquid–water system is introduced. We compared the polymorphic crystallization processes of glycine in pure water, a hydrophilic ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF4)- and a hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6)-water system. In these three cases, the mixture was predominantly composed of the metastable α-glycine, while the least stable β-glycine was only observed during the growth of crystals at room temperature and 32% humidity. The phase transformation from α- to β-glycine was clearly observed through the change in the intensity of characteristic peaks at 29.9° and 18.0° (2 theta) in the XRD patterns. In addition, the effect of the ionic liquid [Bmim]PF6 as an anti-solvent on the re-crystallization process of glycine from three commercially available brands was estimated. Also, the satisfactory reproducibility was obtained from glycine crystallization in the ionic liquid [Emim]BF4-water system in four independent experiments. Therefore, laboratory-based powder XRD analysis can not only provide dynamic information about phase transformation in situ, but can also discover the unstable or transition state in the polymorphic design and control crystallization processes by adding ionic liquids or other additives.
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高影响因子
RSC Advances
·
2021
·Vol. 11
·期 13
·7294-7304
·
IF 3.361
Zheng Yue,Meihuan Yao,Guangyue Bai,Jiuxia Wang,Kelei Zhuo,Jianji Wang,Yujie Wang
Surfactant plays a critical role in enzymatic multi-functionalization processes. However, a deep understanding of surfactant-enzyme interactions has been lacking up until now due to the extreme complexity of the mixed system. This work reported the effect of cationic gemini surfactants, alkanediyl-α,ω-bis(dimethyldodecylammonium bromide) (C12CSC12Br2, S = 2, 6, and 10) on the enzymatic activity and conformation of α-chymotrypsin (α-CT) in phosphate buffer solution (PBS, pH 7.3). The enzymatic activity was assessed by the rate of 2-naphthyl acetate (2-NA) hydrolysis measured by UV-vis absorption. The superactivity of α-CT in the presence of C12CSC12Br2 appears in the concentration region below the critical micelle concentration (cmc) of the surfactant, and its maximum superactivity is correlated to the spacer length of C12CSC12Br2. Subtle regulation of the charge density of headgroups of the cationic surfactant can be achieved through partial charge neutralization of cationic headgroups by introducing inorganic counterions or oppositely charged surfactant, demonstrating that the electrostatic interaction plays the crucial role for emergence of the superactivity. The interaction between C12CSC12Br2 (S = 2,6, and 10) and α-CT was characterized by isothermal titration calorimetry (ITC), and the obtained endothermic enthalpy change indicates that the interaction induces the change in conformation and enzymatic superactivity. The methodologies of fluorescence spectroscopy, circular dichroism (CD), and differential scanning calorimetry (DSC) show that the gemini surfactants with different spacer lengths induct and regulate the secondary, tertiary and even fourth structures of the protein. The present work is significant to get deeper insight into the mechanism of the activation and denaturation of enzymes.
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高影响因子
危险品化学品经营许可证（带存储）