In this work, platinum nanoparticles were dispersed on SBA-15 mesoporous material by incipient wetness method and the synthesized materials were characterized by XRD, TEM, EDX spectroscopies and N2 adsorption-desorption isotherm measurement. The results indicated that 2D hexagonal ordered structure of SBA-15 was still maintained after grafting Pt on SBA-15 support and platinum nanoparticles existed both inside and outside the pore channels of SBA-15 material. Catalytic activity of these materials was tested in the aqueous phase D-glucose oxidation as a model reaction. ...
Polymers present a class of materials that play a role of importance growing in catalysis. Polymeric catalysts based on polypropylene-polyacrylic acid (PP-APA) were prepared by the two methods: co-polymerization in the presence of transition metal ions (Cu(II), Fe(III), Co(II), Mn(II)…) and soaking method. Their catalytic activity was determined by oxidation reactions of ions S2- and hydroquinone by molecular oxygen in normal condition.
Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Self-assembly of copper and cobalt complexes with hierarchical size and catalytic properties for hydroxylation of phenol
ITuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: nﬂuence of Rare Earth Doping on the Structural and Catalytic Properties of Nanostructured Tin Oxide
Characterization and elucidation of the size-dependent evolution of the physical
and chemical properties of finite materials aggregates, having discrete
quantized energy level spectra, specific structural and morphological motifs
and exhibiting unique dynamical characteristics, are among the outstanding
challenges of modern materials science.
Transparent heat mirror thin films have high transmittance in the visible range of wavelength and high reflectance in the infrared range of wavelength. TiO2/TiN/TiO2 films prepared via a D.C reactive magnetron sputtering method on Corning glass and Alkali glass substrates, serve as transparent heat mirrors. The outer TiO2 layer has both the photo-catalytic and anti-reflective properties. The experiment data showed that the film thickness required for photocatalytic properties exceeds 350nm.
Fe-SBA-15 and Fe-SBA-16 ordered mesoporous materials were synthesized via hydrothermal treatment by in situ incorporating Fe(III) oxalate complex species into framework of SBA-15 and SBA-16. The prepared samples were characterized by different techniques such as XRD, BET, UV- Vis and TEM. The obtained results showed that both Fe-SBA-15 and Fe-SBA-16 samples have an ordered mesoporous structure. The hexagonal symmetry of Fe-SBA-15 and cubic ones of Fe-SBA- 16 were not affected by incorporation of Fe into SBA-15 and SBA-16 frameworks.
Although alkaline phosphatase (APase) fromEscherichia
colicrystallizes as a symmetric dimer, it displays deviations
from Michaelis–Menten kinetics, supported by a model
describing a dimeric enzyme with unequal subunits [Orha-novic´ S., Pavela-Vrancˇicˇ M. and Flogel-Mrsˇic´ M. (1994)
Acta. Pharm.44, 87–95]. The possibility, that the observed
asymmetry could be attributed to negative cooperativity in
binding, has been examined. The influence of the
metal ion content on the catalytic properties of APase from
E. colihas been examined by kinetic analyses. ...
We live in the age of biology—the human and many other organisms’
genomes have been sequenced and we are starting to understand the
function of the metabolic machinery responsible for life on our planet.
Thousands of new genes have been discovered, many of these coding for
enzymes of yet unknown function. Understanding the kinetic behavior
of an enzyme provides clues to its possible physiological role. From
a biotechnological point of view, knowledge of the catalytic properties
of an enzyme is required for the design of immobilized enzyme-based
“There’s Plenty of Room at the Bottom” ⎯ this was the title of the lecture Prof. Richard Feynman delivered at California Institute of Technology on December 29, 1959 at the American Physical Society meeting. He considered the possibility to manipulate matter on an atomic scale. Indeed, the design and controllable synthesis of nanomaterials have attracted much attention because of their distinctive geometries and novel physical and chemical properties.
Just as the chemical and physical properties of petroleum have offered challenges
in selecting and designing optimal upgrading schemes, they also introduce
challenges when determining the effects of petroleum and its product on the environment.
In particular, predicting the fate of the polynuclear aromatic systems,
the heteroatom systems (principally, compounds containing nitrogen and sulfur),
and the metal-containing systems (principally, compounds of vanadium, nickel,
and iron) in the feedstocks is the subject of many studies and migration models....
Now neutron diffraction is widely applied for the research of crystal, magnetic structure and internal stress of crystalline materials of various classes, including nanocrystalls. In the present book, we make practically short excursion to modern state of neutron diffraction researches of crystal materials of various classes.
Catalysis and Electrocatalysis at Nanoparticle Surfaces reflects many of the new
developments of catalysis, surface science, and electrochemistry. The first three
chapters indicate the sophistication of the theory in simulating catalytic processes
that occur at the solid–liquid and solid–gas interface in the presence of external
potential. The first chapter, by Koper and colleagues, discusses the theory of
modeling of catalytic and electrocatalytic reactions.
Investigations of kinetics of p-xylene deep oxidation on CuO/ -Al2O3 and CuO/ZSM-5 have been carried out. Specific surface area and pore size of catalyst samples as well as metallic state characteristics and catalytic properties of copper have been established. Catalyst CuO/ZSM-5 has been found to be more active than the first one, but it expressed lower stability because of less stable active form of Cu2+ on zeolite surface.
In Bacteria and Archaea, high-affinity potassium uptake is mediated by the
ATP-driven KdpFABC complex. On the basis of the biochemical properties
of the ATP-hydrolyzing subunit KdpB, the transport complex is classified as
type IA P-type ATPase.
The purpose of this work was to study the catalytic properties of rat buty-rylcholinesterase with benzoylcholine (BzCh) and N-alkyl derivatives of
BzCh (BCHn) as substrates. Complex hysteretic behaviour was observed in
the approach to steady-state kinetics for each ester. Hysteresis consisted of
a long lag phase with damped oscillation.