ELECTROANALYSIS
·
2012
·Vol. 24
·期 2
·286-292
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IF 2.872
Chengxiang Ruan,Li Xu,Xiuzhen Wang,Jin Lou,Weimin Gao,Wei Sun
In this paper a molecular wire modified carbon paste electrode (MW-CPE) was firstly prepared by mixing graphite powder with diphenylacetylene (DPA). Then a graphene (GR) and chitosan (CTS) composite film was further modified on the surface of MW-CPE to receive the graphene functionalized electrode (CTS-GR/MW-CPE), which was used for the sensitive electrochemical detection of adenosine-5′-triphosphate (ATP). The CTS-GR/MW-CPE exhibited excellent electrochemical performance and the electrochemical behavior of ATP on the CTS-GR/MW-CPE was carefully studied by cyclic voltammetry with an irreversible oxidation peak appearing at 1.369 V (vs. SCE). The electrochemical parameters such as charge transfer coefficient ( α ) and electrode reaction standard rate constant ( k s ) were calculated with the results of 0.53 and 5.28×10 −6 s −1 , respectively. By using differential pulse voltammetry (DPV) as detection technique, the oxidation peak current showed good linear relationship with ATP concentration in the range from 1.0 nM to 700.0 µM with a detection limit of 0.342 nM (3 σ ). The common coexisting substances, such as uric acid, ascorbic acid and guanosine-5′-triphosphate (GTP), showed no interferences and the modified electrode was successfully applied to injection sample detection.
研究领域:
分析化学
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生物医学工程
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RAPID COMMUNICATIONS IN MASS SPECTROMETRY
·
2020
·Vol. 34
·期 21
·e8899
·
IF 2.2
Hanfeng Jin,Jiuzhong Yang,Aamir Farooq
Rationale Aromatic hydrocarbons play an important role in the formation and growth of polycyclic aromatic hydrocarbon (PAH) and soot particles. Measurements of their absolute photoionization cross-sections (PICSs), that benefit the quantitative investigation of mass spectrometry, are still lacking, however. Methods PICSs of some aromatic hydrocarbons were measured with tunable synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). Nitric oxide and benzene were chosen as standard references for PICS calibration, since their photoionization cross-sections are well documented in the literature. Binary liquid mixtures of the investigated molecules and their specific solvents were used in the measurements. Results The investigated aromatics include naphthalene, phenanthrene, 1-methylnaphthalene, indene, 2-/3-/4-methylphenylacetylene, 2-methylindene, diphenylacetylene, 1-/2-ethynylnaphthalene and acenaphthylene. Photo-induced fragments from the molecules were also observed with increasing photon energy. Conclusions Based on our measurements and literature data, PICSs of most aromatic molecules have very similar values beyond their ionization energies. However, molecules that contain the phenylacetylene structure have PICSs higher than other aromatics.
研究领域:
分析化学
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质谱学
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大气化学
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环境科学
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DOI
PubMed
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Yuan Ren,Ruiyun Guo,Yanan Li,Zixin Ge,Yaohui Zhao,Jiapeng Huang,Qian Wang,Junhao Lu,Mingshang Jin
While electrochemical semihydrogenation (ESH) of alkynes using water-derived hydrogen presents an eco-friendly alternative to traditional thermocatalytic methods, achieving high alkene selectivity remains fundamentally constrained by subsurface hydrogen accumulation in palladium (Pd)-based electrocatalysts. To address this challenge, we developed a class of carbon-doped Pd nanocubes (PdCx NCs) with precisely modulated interstitial carbon occupancy in lattice interstitial sites. The optimized PdC0.15 NCs achieved high catalytic performance with 95.4% alkene selectivity at −1.0 V (vs Hg/HgO) and full conversion, representing a 3-fold selectivity enhancement over pure Pd counterparts without activity compromise. Through comprehensive structural and electrochemical characterization, we identified two critical mechanistic advantages: (1) carbon intercalation effectively suppresses subsurface hydrogen formation through lattice occupation effects, and (2) strategically weakened intermediate adsorption energetics prevent overhydrogenation pathways. In situ spectroscopic analysis and deuterium isotope tracing elucidated water-derived H* as the active hydrogen species, facilitating radical-mediated hydrogenation that preserves sensitive functional groups (e.g., C–Cl bonds) while achieving complete Z-selectivity for challenging internal alkynes. This interstitial doping strategy fundamentally resolves the inherent selectivity limitations of Pd catalysts, establishing an energy-efficient platform for ambient-condition synthesis of high-yield alkenes with preserved functionality.
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JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Xilun Zhang,Hongliang Liang,Fei Chang
Catalytic hydrogenation of alkynes to alkenes is pivotal in both petrochemical and fine chemical industries. Its implementation relies on the use of transition metals, especially those precious Pd-based catalysts. In this work, we utilize a melt infiltration method to prepare magnesium oxide-supported potassium hydride (KH/MgO), which is illustrated as a transition-metal-free catalyst for selective hydrogenation of alkynes. H 2 -D 2 exchange experiment proves that dihydrogen activation and dissociation on KH/MgO is plausible at room temperature and ambient pressure. KH/MgO catalyzes hydrogenation of diphenylacetylene (DPA) already at 40 ℃, implying its high intrinsic activity at very mild conditions. Under an optimized condition of 80°C, 2 bar H 2 , and 40 h, 75 % conversion of DPA is achieved, affording 82 % selectivity to stilbenes. Mechanistic study suggests that surface hydride on KH/MgO plays an important role toward dihydrogen activation, and involved in the hydrogenation step to form stilbenes. This work shows the promise for using light metal hydrides consisting of earth-abundant elements as alternative hydrogenation catalysts.
研究领域:
化学
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催化科学
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高影响因子
CATALYSIS LETTERS
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2021
·Vol. 151
·期 10
·3004-3010
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IF 3.186
Zhou Junjie,Huang Yu,Shen Jialu,Liu Xiang
The production of H 2 from non-fossil sources is a key research challenge to contributing solving the forthcoming energy problem. Aqueous solutions of tetrahydroxydiboron have very recently appeared as a H 2 source, from which both hydrogen atoms are provided by water, in the presence of highly sophisticated nanocatalysts. Herein, commercial and cheap Pd/C is shown to be an efficient and recyclable catalyst for H 2 evolution upon tetrahydroxydiboron hydrolysis. Graphic Abstract
研究领域:
化学
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能源科学
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高影响因子
Molecular Catalysis
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2021
·
IF 5.062
Lingqi Huang,Kecheng Hu,Ganggang Ye,Zhibin Ye
Soluble small molecular/polymeric ligands are often used in Pd-catalyzed semi-hydrogenation of alkynes as an efficient strategy to improve the selectivity of targeted alkene products. The use of soluble ligands requires their thorough removal from the reaction products, which adds significant extra costs. In the paper, commercially available, inexpensive, metallic sulfide-based solid-phase ligands (SPL8-4 and SPL8-6) are demonstrated as simple yet high-performance insoluble ligands for a heterogeneous Pd nanocatalyst (Pd@CaCO 3 ) toward the semi-hydrogenation of alkynes. Based on the reactions with a range of terminal and internal alkyne substrates, the use of the solid-phase ligands has been shown to markedly enhance the selectivity of the desired alkene products by efficiently suppressing over-hydrogenation and isomerization side reactions, even during the long extension of the reactions following full substrate conversion. A proper increase in the dosage or a reduction in the average size of the solid-phase ligands enhances such effects. With their insoluble nature, the solid-phase ligands have the distinct advantage in their simple, convenient recycling and reuse while without contaminating the products. A ten-cycle reusability test with the SPL8-4/Pd@CaCO 3 catalyst system confirms its well-maintained activity and selectivity over repeated uses. A mechanistic study with x-ray photoelectron spectroscopy indicates that the solid-phase ligands have electronic interactions with Pd in the supported catalyst, contributing to inhibit the binding and further reaction of the alkene products. This is the first demonstration of solid-phase ligands for highly selective semi-hydrogenation of alkynes, which show strong promise for commercial applications.
研究领域:
催化化学
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材料科学
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ANALYTICAL LETTERS
·
2017
·
IF 1.15
Xueliang Niu,Lijun Yan,Zuorui Wen,Xiaobao Li,Yanyan Niu,Yaping Lu,Wei Sun
A carbon molecular wire electrode was fabricated using diphenylacetylene as the modifier and gold nanoparticles were electrodeposited on the surface. The morphology and electrochemical properties of this modified electrode were investigated by scanning electron microscopy and electrochemical impedance spectroscopy. Two well-defined peaks for metol appeared using this gold nanoparticle-modified carbon molecular wire electrode by cyclic voltammetry with a high current response. These results demonstrate a synergistic effect between the gold nanoparticles and the carbon molecular wire electrode resulting in a rapid electrochemical reaction. The electrochemical conditions for metol were optimized on the modified electrode and a detection limit of 0.64 µmol/L and a linear dynamic range between 2.0 to 800.0 µmol/L were obtained. This modified electrode provided good selectivity, high sensitivity, and acceptable reproducibility, demonstrating promise for the determination of metol in the water.
研究领域:
分析化学
·
电化学
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ChemCatChem
·
2017
·Vol. 9
·期 7
·1337-1342
·
IF 4.803
Kaixuan Yang,Xiao Chen,Lei Wang,Liangliang Zhang,Shaohua Jin,Changhai Liang
Graphical Vapor trail : Metal silicide (Pd 2 Si, Ni 2 Si, CoSi, Fe x Si, and Cu 6.69 Si) catalysts supported by SBA-15 are prepared by chemical vapor deposition. Of the SBA-15-supported metal silicide catalysts, Ni 2 Si/SBA-15 presents a modest activity, notable selectivity to styrene (>90 %), and high stability in the selective hydrogenation of phenylacetylene. Metal silicide (Pd 2 Si, Ni 2 Si, CoSi, Fe x Si, and Cu 6.69 Si) catalysts supported by SBA-15 have been prepared by a chemical vapor deposition method under a H 2 atmosphere using (CH 3 ) 2 SiCl 2 as the Si source. Of the SBA-15-supported metal silicide catalysts, Ni 2 Si/SBA-15 presented a modest activity, notable selectivity to styrene (>90 %), and high stability with respect to the selective hydrogenation of phenylacetylene, which is attributed to the active-site isolation and electron transfer in the silicide. Furthermore, Ni 2 Si/SBA-15 also has a high selectivity to diphenylacetylene and 1,4-butynediol, which demonstrates that Ni 2 Si/SBA-15 is a promising, low-cost catalyst alternative to noble-metal catalysts as a selective hydrogenation catalyst.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2018
·
IF 2.88
Yan Liang
Two fluoranthene derivatives with “propeller” structure, named as 7,8,9,10-tetraphenylfluoranthene ( TPFA ) and 3-phenoxy-7,8,9,10-tetraphenyl fluoranthene ( PO - TPFA ), were designed and synthesized by introducing outer phenyl and phenoxy substituents to fluoranthene. Given the steric hindrance of this unique structure, both organic dyes exhibited similar fluorescence spectra and strong fluorescence emission from the solution to the film state. The introduction of a phenoxy group showed obvious influence to the molecular optical properties of fluoranthene. Density functional theory calculations were further conducted to verify this finding. Both dyes were used as fluorescent probes and exhibited and sensitive fluorescence response to nitroaromatic explosives and highly selectivity to picric acid . Furthermore, PO - TPFA exhibited better detection performance to nitroaromatic explosives than TPFA . This work can serve as a guide for molecular fluorescence design because these dyes possess excellent fluorescence in solution and film states and can be used for the sensitive fluorescence detection of nitroaromatic explosives.
研究领域:
化学
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材料科学
·
爆炸物检测
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PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2013
·
IF 2.404
Fan Shi,Shixing Gong,Li Xu,Huanhuan Zhu,Zhenfan Sun,Wei Sun
In this paper, a graphene (GR) ionic liquid (IL) 1-octyl-3-methylimidazolium hexafluorophosphate and chitosan composite-modified carbon molecular wire electrode (CMWE) was fabricated by a drop-casting method and further applied to the sensitive electrochemical detection of adenosine-5′-monophosphate (AMP). CMWE was prepared with diphenylacetylene (DPA) as the modifier and the binder. The properties of modified electrode were examined by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical behaviors of AMP was carefully investigated with enhanced responses appeared, which was due to the presence of GR-IL composite on the electrode surface with excellent electrocatalytic ability. A well-defined oxidation peak of AMP appeared at 1.314 V and the electrochemical parameters were calculated by electrochemical methods. Under the selected conditions, the oxidation peak current of AMP was proportional to its concentration in the range from 0.01 μM to 80.0 μM with the detection limit as 3.42 nM (3 σ ) by differential pulse voltammetry. The proposed method exhibited good selectivity and was applied to the detection of vidarabine monophosphate injection samples with satisfactory results.
研究领域:
电化学
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材料科学
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分析化学
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DOI
PubMed
高影响因子
COMBUSTION AND FLAME
·
2022
·
IF 5.767
Hanfeng Jin,Weiye Chen,Lili Ye,Hao Lou,Qiang Xu,Beibei Feng,Zhandong Wang,Aamir Farooq
The reaction between phenyl radical and phenylacetylene is a prototype for the reactions of aryl radicals and alkynyl peri‑condensed aromatic hydrocarbons (PCAHs), which may help explain the dimerization of PCAHs by covalent bond with acetylene assistance. In this work, we have experimentally and theoretically investigated reaction kinetics of phenyl radical and phenylacetylene. Gas chromatography-mass spectrometry (GC–MS) is applied to separate and identify molecular structures of reaction products in a jet-stirred reactor (JSR). Diphenylacetylene is observed as the major product of this reaction, which shows dominant concentration near 1000 K. Formation of phenanthrene increases with temperature, while 9-methylene-fluorene is a minor product, and 2-ethynyl-biphenyl is negligible. The potential energy surface and rate coefficients of phenyl and phenylacetylene reaction are calculated by quantum chemistry and transition state theory. 1,2-Diphenylvinyl is the only resonance-stabilized radical (RSR) among the adducts formed via all six possible addition reaction channels. Its formation reaction channel has a much lower energy barrier and deeper potential well and, therefore, it wins the competition in the reaction of phenyl and phenylacetylene at combustion-relevant intermediate temperatures.
研究领域:
燃烧化学
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物理化学
·
化学动力学
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高影响因子
ChemSusChem
·
2021
·Vol. 15
·期 4
·e202102455
·
IF 8.928
Xingwang Lan,Juan Wang,Qing Li,Aiqing Wang,Yize Zhang,Xianheng Yang,Guoyi Bai
Graphical Building bridges : Acetylene or vinylene-bridged π-conjugated covalent triazine polymers, A-CTP-DPA and V-CTP-DPE, are fabricated toward metal-free photocatalytic oxidation under visible light irradiation. Impressively, compared to the one without acetylene or vinylene bridge, A-CTP-DPA and V-CTP-DPE exhibit superior activity in photocatalytic selective oxidation of sulfides and oxidative coupling of amines. Solar-driven photocatalytic chemical transformation provides a sustainable strategy to produce valuable feedstock, but designing photocatalysts with high efficiency remains challenging. Herein, two acetylene- or vinylene-bridged π-conjugated covalent triazine polymers, A-CTP-DPA and V-CTP-DPE, were successfully fabricated toward metal-free photocatalytic oxidation under visible light irradiation. Compared to the one without acetylene or vinylene bridge, both resulting polymers exhibited superior activity in photocatalytic selective oxidation of sulfides and oxidative coupling of amines; in particular, A-CTP-DPA delivered an optimal photocatalytic performance. The superior activity was attributed to the broadened spectral response range, effective separation, rapid transportation of photogenerated charge carriers, and abundant active sites for photogenerated electrons due to the existence of the acetylene bridge in the framework. This work highlights the potential of acetylene and vinylene bridges in tuning catalytic efficiency of organic semiconductors, providing a guideline for the design of efficient photocatalysts.
研究领域:
材料科学
·
光化学
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PubMed
高影响因子
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