scholarly journals Oxygen Affinity of Transition Metal Cations: A Coherent Descriptor in Catalytic Oxygenate Transformations

2021 ◽  
Author(s):  
Huixiang Li ◽  
Peifang Yan ◽  
B.Q. Xu ◽  
Conrad Zhang
Keyword(s):  
Interaction Strength ◽  
Oxygen Affinity ◽  
Metal Cations ◽  
Intrinsic Property ◽  
Far Infrared ◽  
Dissociation Kinetics ◽  
Metal Chlorides ◽  
Glucose Isomerization ◽  
Kinetics Of

This work reports a complementary descriptor to acidity for metal cations, oxygen affinity, to scale the interaction strength of metal cations with oxygenate groups. A method for measuring oxygen affinity is developed in alkyl methylimidazolium chloride solvents using in-situ far infrared (FIR) spectroscopy. The relative oxygen affinity values of metal cations in metal chlorides with model compounds including cyclopentanol (for alcohols), cyclohexanone (for ketones), ethylene glycol diethyl ether (for ethers), and H2O are measured from the dissociation kinetics of the metal-oxygenate complexes. The concentrations of metal-chloride and metal-oxygenate complexes are determined during evaporative removal of oxygenate molecules according to the FIR absorbance of metal-Cl bonds. The oxygen affinity values are shown to reasonably account for the catalytic performances of metal cations in furfural-acetone condensation and glucose isomerization reactions. The oxygen affinity descriptor could be potentially exploited as an intrinsic property of metal cations broadly in metal chlorides and metal oxides.

Manipulating the water dissociation kinetics of Ni3N nanosheets via in situ interfacial engineering

2019 ◽  
Vol 7 (18) ◽  
pp. 10924-10929 ◽  
Author(s):  
Shuwen Niu ◽  
Yanyan Fang ◽  
Jianbin Zhou ◽  
Jinyan Cai ◽  
Yipeng Zang ◽  
...  
Keyword(s):  
Water Dissociation ◽  
Dissociation Kinetics ◽  
Interfacial Engineering ◽  
Kinetics Of

The sluggish water dissociation kinetics of Ni3N is significantly accelerated by in situ interfacial engineering. Owing to the unique synergy between Ni3N and MoO2, Ni3N/MoO2 displays exceptional alkaline HER activity.

scholarly journals Structure-Induced Dynamics of Erythrocyte Aggregates by Microscale Simulation

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Tong Wang ◽  
Zhongwen Xing ◽  
Dingyu Xing
Keyword(s):  
Blood Flow ◽  
Interaction Strength ◽  
Erythrocyte Aggregation ◽  
Immersed Boundary ◽  
Dissociation Kinetics ◽  
Intercellular Interaction ◽  
Fundamental Understanding ◽  
Membrane Stiffness ◽  
Kinetics Of

Erythrocyte aggregation and dissociation play an important role in the determination of hemodynamical properties of blood flow in microcirculation. This paper intends to investigate the adhesion and dissociation kinetics of erythrocytes through computational modeling. The technique of immersed boundary-fictitious domain method has been applied to the study of erythrocyte aggregates traversing modeled stenotic microchannels. The effects of stenosis geometry, cell membrane stiffness, and intercellular interaction strength on aggregate hemodynamics including transit velocity are studied. It is found that the width of the stenosis throat and shape of stenosis have a significant influence on the dissociation of the aggregates. Moreover, horizontally orientated erythrocyte aggregates are observed to dissociate much easier than their vertical counterparts under the same simulation conditions. Results from this study contribute to the fundamental understanding and knowledge on the biophysical characteristics of erythrocyte aggregates in microscopic blood flow, which will provide pathological insights into some human diseases, such as malaria.

In Situ Raman Study of the Formation and Dissociation Kinetics of Methane and Methane/Propane Hydrates

2020 ◽  
Vol 34 (5) ◽  
pp. 6288-6297
Author(s):  
Hai S. Truong-Lam ◽  
SeongDeok Seo ◽  
Suhkmann Kim ◽  
Yongwon Seo ◽  
Ju Dong Lee
Keyword(s):  
Dissociation Kinetics ◽  
In Situ Raman ◽  
Raman Study ◽  
Kinetics Of

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

In situ observation of the martensitic transformation in (Mg,Y)-PSZ

1986 ◽  
Vol 44 ◽  
pp. 500-501
Author(s):  
R-R. Lee
Keyword(s):  
Martensitic Transformation ◽  
High Strength ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Considerable Potential ◽  
Transmission Electron ◽  
Structural Applications ◽  
Applied Stresses ◽  
Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

Growth kinetics of Al2Cu in an Al-1.5Cu thin film by in Situ TEM

1993 ◽  
Vol 51 ◽  
pp. 1172-1173
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson
Keyword(s):  
Thin Film ◽  
In Situ Tem ◽  
Collector Plate ◽  
Transmission Electron ◽  
Device Processing ◽  
Corrosion Susceptibility ◽  
Precipitation Phenomena ◽  
Semiconductor Chips ◽  
Kinetics Of

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Catalytic activity of rhodium(I) complexes containing (ω-trimethylsilylalkyl)diphenylphosphines

1980 ◽  
Vol 45 (8) ◽  
pp. 2219-2223 ◽  
Author(s):  
Marie Jakoubková ◽  
Martin Čapka
Keyword(s):  
Catalytic Activity ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Electron Density ◽  
Phosphorus Atom ◽  
Proton Acceptor ◽  
Trimethylsilyl Group ◽  
Kinetics Of

Kinetics of homogenous hydrogenation of 1-heptene catalysed by rhodium(I) complexes prepared in situ from μ,μ'-dichloro-bis(cyclooctenerhodium) and phosphines of the type RP(C6H5)2 (R = -CH3, -(CH2)nSi(CH3)3; n = 1-4) have been studied. The substitution of the ligands by the trimethylsilyl group was found to increase significantly the catalytic activity of the complexes. The results are discussed in relation to the electron density on the phosphorus atom determined by 31P NMR spectroscopy and to its proton acceptor ability determined by IR spectroscopy.

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