镍系非晶态合金催化剂的研究进展

镍系非晶态合金催化剂作为一类以镍为主要活性组分的环境友好型催化剂,具有高活性、高选择性和价格低廉等特性,被广泛应用于不饱和化合物的催化加氢、化合物脱硫、硼氢化物水解和燃料电池中的电催化氧化等方面。本文概述了镍系非晶态合金催化剂的结构特点,综述了镍系非晶态合金催化剂近年来国内外的研究状况,重点总结金属助剂、载体、制备方法对镍系非晶态合金催化剂的性能的影响,并对镍系非晶态催化剂的未来研究方向进行了分析展望。     

Glycerol steam reforming over Ni–Fe–Ce/Al2O3 catalyst for hydrogen production

Research on Chemical Intermediates - In this study, we focused on the catalytic activity, stability, and kinetics of glycerol steam reforming (GSR) for the hydrogen production over...     

Synthesis and characterization of Al-modified SBA-15 for Fischer–Tropsch synthesis (FTS) reaction

Research on Chemical Intermediates - In this work, we synthesized a Co-based catalyst supported on modified SBA-15 to obtain the uniform particle size of active metal and selective products with...     

Density functional theory prediction of cobalt pincer complexes for catalytic dehydrogenation of ethanol

A density functional theory (DFT) study reveals that dehydrogenation of ethanol catalyzed by aliphatic PNP pincer cobalt complexes, [(PNP^Et)Co(H)(OMe)] (1a) and [(PNP^Et)Co(H)(CH₂SiMe₃)] (1b) (PNP^Et = bis(2-(diethylphosphino)ethyl)amine), undergoes a self-promoted mechanism, in which an ethanol assists the formation of H₂ as a bridge for proton transfer. The calculated total free energy barriers of ethanol dehydrogenation catalyzed by 1a and 1b are 23.9 and 22.2 kcal mol^?1, respectively, which indicate that 1b is a promising catalyst for the dehydrogenation of ethanol under mild conditions.     

Discrimination of Fluoroamphetamine Regioisomers by Raman Spectroscopy

The ability of a portable Raman spectrometer to perform on‐site and real time discrimination of fluoroamphetamine regioisomers demonstrated in this study. It suggests the presence and the position shifts of Star of David ring breathing vibration around 1000 cm^?1 and C? F stretching vibrations are assigned at 1232 cm^?1 (2‐FA), 1241 cm^?1 (3‐FA) and 1217 cm^?1 (4‐FA) are good indicators to differentiate ortho‐, meta‐ and para‐FAs, whereas the C? F vibrational shifts can help to confirm the determination.     

Chemical Constituents from Termite‐associated Xylaria acuminatilongissima YMJ623

Three previously unreported benzofurans, namely acumifurans A–C ( 1 – 3 ), along with five known compounds, 2‐(isopropyl‐1′‐ol)‐2,3‐dihydrobenzofuran‐5‐carbinol ( 4 ), fomannoxin alcohol ( 5 ), fomannoxin ( 6 ), acremine S ( 7 ) and cyclo(L ‐Pro‐L ‐Leu) ( 8 ), were isolated from the ethyl acetate extracts of the fermented broths of termite n est associated Xylaria acuminatilongissima YMJ623. Compound 4 , a synthe tic benzofuran analogue of 1 – 3 , was isolated for the first time from natural resources. The str uctures of 1 – 8 were determined through spectroscopic data analyses. The absolute configurations of 1 – 4 were established based mainly on ROESY experiment and Mosher’s reaction, and compared the optical rotation data with the literatures. The effects of these compounds on the inhibition of NO production in lipopolysaccharide (LPS)‐activated murine macrophage RAW264.7 cells were also evaluated. Of the compounds tested, 6 showed a mild NO production inhibitory activity without any cytotoxicity, and its mean maximum inhibition (E_max) at 100 μM was 42.98±0.87 %.     

A glassy carbon electrode modified with MoS<Subscript>2</Subscript> nanosheets and poly(3,4-ethylenedioxythiophene) for simultaneous electrochemical detection of ascorbic acid,dopamine and uric acid

We describe a chemical exfoliation method for the preparation of MoS₂ nanosheets. The nanosheets were incorporated into poly(3,4-ethylenedioxythiophene) (PEDOT) by electrodeposition on a glassy carbon electrode (GCE) to form a nanocomposite. The modified GCE is shown to enable simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA). Due to the synergistic effect of MoS₂ and PEDOT, this electrode displays better properties in terms of electrocatalytic oxidation of AA, DA and UA than pure PEDOT, which is illustrated by cyclic voltammetry and differential pulse voltammetry (DPV). Under optimum conditions and at pH 7.4, the respective sensitivities and best working potentials are as follows: AA: 1.20 A?mM^?1?m^?2, 30 mV; DA: 36.40 A?mM^?1?m^?2, 210 mV; UA: 105.17 A?mM^?1?m^?2, 350 mV. The calculated detection limits for AA, DA and UA are 5.83 μM, 0.52 μM and 0.95 μM, respectively. The modified electrode was applied to the detection of the three species in human urine samples and gave satisfactory results.

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Graphical abstract MoS₂ nanosheets were prepared by a facile chemical exfoliation method. MoS₂ and poly(3,4-ethylenedioxythiophene) nanocomposite modified glassy carbon electrodes were fabricated, which are shown to enable simultaneous determination of ascorbic acid, dopamine and uric acid with high sensitivity and selectivity.

     

Supramolecular imprinted electrochemical sensor for the neonicotinoid insecticide imidacloprid based on double amplification by Pt-In catalytic nanoparticles and a Bromophenol blue doped molecularly imprinted film

The authors describe an electrochemical sensor for the neonicotinoid insecticide imidacloprid (IMI) based on Pt-In catalytic nanocomposite film and Bromophenol blue amplification. The Pt-In nanocomposite film was deposited on the surface of a modified glassy carbon electrode. The composite molecularly imprinted polymer (MIP) was prepared by electro-polymerization using bromophenol blue doped o-aminophenol as functional monomer and 4-tert-butylcalix[6]arene-IMI supramolecular inclusion complex as template molecule. The experimental results showed that the current intensity of IMI was clearly amplified in the potential range from ?0.3 to ?1.8 V, because of the double amplification, based on the Pt-In film and Bromophenol blue catalysis. Moreover, the double recognition ability of the sensor, which relied on the MIP and the vacuum structure of 4-tert-butylcalix[6]arene, effectively increased the specific recognition performance. The feasibility of its practical applications has been demonstrated by the analysis of vegetable samples.

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Graphical abstract A supramolecular imprinted electrochemical sensor for imidacloprid determination was prepared based on Pt-In nanocomposite film and bromophenol blue amplification. Because of the advantages of the specific recognition sites in MIPs and supramolecular chemistry, the sensor showed good selectivity for imidacloprid.

     

Sentaurus® based modeling and simulation for GFET's characteristic for ssDNA immobilization and hybridization

The graphene field effect transistor (GFET) has been widely studied and developed as sensors and functional devices. The first report about GFET sensing simulation on the device level is proposed. The GFET's characteristics, its responding for single strand DNA (ssDNA) and hybridization with the complimentary DNA (cDNA) are simulated based on Sentaurus, a popular CAD tool for electronic devices. The agreement between the simulated blank GFET feature and the reported experimental data suggests the feasibility of the presented simulation method. Then the simulations of ssDNA immobilization on GFET and hybridization with its cDNA are performed, the results are discussed based on the electron transfer (ET) mechanism between DNA and graphene.