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. ...
Recovering useful hydrocarbons from sewage sludge using zirconia-supporting iron oxide catalysts was investigated. Zirconia has activity for decomposing water molecules to generate active oxygen and hydrogen species.
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.
“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.
I would like to express gratitude to the many people who contributed
to this book. Special thanks to Alberto Ibargüen and
Paula Ellis at the John S. and James L. Knight Foundation who
supported both the research and our Harvard Kennedy School
convenings of leading civic entrepreneurs. I am indebted to
Vanessa Kirsch and Kim Syman and their colleagues at New
Profi t Inc. for sharing their experiences and vision for promoting
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.
In petroleum industry, it is desirable to produce lighter hydrocarbons such as gasoline, kerosene and gas–oil from unused heavy oils. Thus we have developed zirconia-supporting iron oxide catalysts View the MathML source to decompose petroleum residual oil (atmospheric distilled residual oil) with steam.
The catalytic competence of the natural thrombin mutant with deletion of
the Lys9 residue in the A-chain (DK9) was found to be severely impaired,
most likely due to modification of the 60-loop conformation and catalytic
triad geometry, as supported by long molecular dynamics (MD) simula-tions in explicit water solvent.
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. ...
The term NEMCA refers to nonfaradaic electrochemical modiﬁcation of catalytic activity. The NEMCA effect is also known as electrochemical promotion or electrochemical promotion of catalysis (EPOC) or electropromotion. It is the effect observed on the rates and selectivities of catalytic reactions taking place on electronically conductive catalysts deposited on ionic (or mixed ionic–electronic) supports upon application of electric current or potential (typically 72 V) between the catalyst and a second (counter or auxiliary) electrode also deposited on the same support. ...
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.
The USG’s long history and successful programming in Indonesia provides examples of the GHI principles in action. Working under the guidance of national strategies and priorities and in partnership with government and private sector, investing in innovation, putting the interests of women and girls at the center of programming and increasing impact through strategic coordination have all been core approaches used by the USG in Indonesia and will continue to guide its work.
Large-pore three-dimensional (3D) mesoporous silicas are among the most interesting mesoporous materials discovered in recent years, and they have attracted much attention for potential applications requiring easily accessible, uniform and large pores. Examples of these are SBA-15 (p6 mm) and SBA-16 (Im3m), which have cylindrical- and cage-type structures, respectively.
A new set of experimental kinetic data on the hydrolysis of a series of
phenylacetylp-substituted anilides catalyzed by penicillin G acylase from
Escherichia coli(PGA) is presented in this article. The Hammett plot of
⁄kcat,H) versus rp
has three linear segments, which distinguishes
the enzyme from the other N-terminal nucleophile hydrolases for which
data are available.