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Showing 1 to 20 of 27 for “"catalyst preparation"”.
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Surface science approach to catalyst preparation
… of surface science studies related to the preparation of supported metal catalysts on well-defined oxide surfaces applying procedures used in real-world catalysis are presented. Specifically, a thin Fe3O4(111) film grown on Pt(111) was chosen as support and its surface was exposed to …
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Characterising catalyst preparation: from adsorbed precursor complex to catalyst particle
Catalyst performance can be enhanced by the high dispersion of precious metals onto supports. The deposition of metal particles and the structural arrangement they adopt once impregnated on a support is therefore of interest in determining the necessary conditions required for maximum catalyst …
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Catalyst preparation and evaluation for synthesis of anisole by phenol aklylation
Includes bibliographical references.
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Evaluation of alkali and alkaline earth doped samarium oxide catalysts for the oxidative coupling of methane
… to 900°C) in the presence of a solid metal oxide catalyst to produce the desirable products, ethane and ethylene, as well as the undesirable products, carbon monoxide and carbon dioxide. Although the homogeneous reactions are well understood, the heterogeneous reactions and their effect on the …
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Characterization of gold catalysts for methanol synthesis
The activity (per mass of catalyst) of supported gold catalysts across a range of reduction and oxidation reactions is significantly affected by the average crystallite size of the gold crystallites in the catalyst. Supported gold catalysts are most commonly characterized for particle size using …
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Reactor Design for Partial Upgrading of Bitumen via Aquaprocessing
… experimental results indicate that the effect of catalyst particle size depends on the catalyst preparation techniques. The steam diffusivity in bitumen was found to increase linearly with increase in reaction temperature. 0.05 psi/m pressure drop and 39 vol.% liquid holdups are predicted for the …
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Part I: Mechanistic Insight in Alkyl-Alkyl and Aryl-Aryl Negishi Cross-Coupling Part II: Large Scale Synthesis of NHC Precursors: 2,6-DI(3-Pentyl) Aniline and 2,6-DI (4-Heptyl) Aniline
… using Pd-PEPPSI-IPent (Pyridine-Enhanced Pre-catalyst Preparation Stabilization and Initiation) pre-catalyst has been developed. The method requires no additive (such as LiX) or use of a polar co-solvent (such as THF/DMI) and reactions proceed in THF solvent alone. The transmetalating species …
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Investigation of the potential catalytic activities of several metal organic framework (MOF) materials
… Ni(FA) and Zn(FA). These MOFs are used as catalyst supports for iron or platinum nanoparticles. The catalysts are prepared using incipient wetness impregnation method and characterized with Brunauer-Emmett-Teller (BET), pulse chemisorption, X-ray diffraction (XRD), temperature-programmed …
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A characterization and study of barium promoted silver catalysts for the partial oxidation of ethylene
… using oxygen was studied. Six silver-based catalysts were prepared, and the effects of BaCO<sub>3</sub> and BaO<sub>2</sub> as moderators were investigated. Silver components of the catalysts were either AgO or Ag<sub>2</sub>CO<sub>3</sub>.</p> <p>The catalysts were characterized before and …
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Nanosized iron crystallites for Fischer-Tropsch synthesis
… are cobalt and iron. In this work iron-based catalysts were studied. To ensure maximum metal utilisation and therefore a high weight specific catalytic activity, the metal crystallites should possess large specific surface areas and that is only achievable with small metal crystallites. …
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Development and Application of in Situ/Operando Spectroscopic Techniques for Understanding Active Sites and Surface Intermediate Species in Heterogeneous Catalysis
… systems, enabling detailed insights into catalyst structures, reaction intermediates, and mechanisms. This thesis presents the application of innovative methods, including in situ transient Raman spectroscopy, Differential Derivative Reflectance (DDR) UV-Vis Spectroscopy, Modulation …
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Design and use of novel metal catalysts in organic synthesis
… and synthesis of novel dirhodium carboxylate catalysts, and their precursor ligands, for use as enantioselective catalysts in transformations of α-diazocarbonyl compounds. Chapter One focuses on the literature background over the past thirty years in transition metal-catalysed asymmetric …
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Heterogeneous catalysis in the different reactor types on the examples of ethyl benzene to styrene, methane dehydroaromatization and propylene carbonate, methanol transesterification
… as e.g. contact times, temperature control, catalyst regeneration procedure etc. can be varied and adjusted to the special reaction requirements. Correct reactor choice is the decisive factor for the optimal reaction performing. One of the objectives of this work is to find a way to produce …
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Part I: Palladium PEPPSI-IPENT CI, A Useful Catalyst for Challenging Amination Reactions Part II: Generation Of Benzynes in Flow Reactors followed by Subsequent Diels-Alder Reactions
… Hartwig amination reactions using Pd-NHC pre-catalysts. Specifically, we focused on: a) coupling of sterically hindered primary and secondary amines and b) coupling of 2-aminopyridine derivatives with aryl and heteroaryl halides. Although several approaches have been developed and proven to be …
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Development of bimetallic Pd-Zn catalysts for methanol steam reforming: hydrogen production for fuel cells
… it can be easily handled. Typically, Cu-based catalysts are used for steam reforming of methanol due to their high activity (i.e. H₂ production) and high selectivity towards CO₂. As CO poisons anodic catalyst of PEMFC, high selectivity towards CO₂ is crucial so as to eliminate or at least …
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PEM-fuel cell catalysts from nanoscopic precursors : a comparative study
… to 60% from the amount usually applied for the preparation of Pt/Ru organosol using a combination of (Octyl)4N[Bet3H] and Li[Bet3H] as reductants. Further, it was found that the particle size can be controlled during this synthesis by the "reverse" addition of suspended metal salts to the …
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Exploring Enantioselective and Multicomponent One-Pot Reactions Utilizing Alkynes as Linchpins Toward Biologically Active Molecules
… dienes. Herein we report a new BINOL-Al-Cl catalyst preparation that is robust enough to catalyze such a reaction with great success both in terms of yield and enantiomeric ratios. The products, 1,4-cyclohexadienes, have two regiochemically different alkenes, which can serve as functional …
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The performance of structured cobalt catalysts in Fischer-Tropsch synthesis
Cobalt is the preferred catalyst metal for the production of clean burning, high cetane number diesel fuel from synthesis gas using the Fischer-Tropsch synthesis. Hence, increasing C5+ selectivity of cobalt catalysts is one of the hot topics in Fischer-Tropsch synthesis. Internal mass transport …
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Gold catalysts prepared by ion exchange for use in ethylene glycol oxidation: An exploratory study
… focuses on a relatively uncommon method of gold catalyst preparation, ion exchange, which involves the suspension of the support in a solution containing cationic or anionic gold complex precursors at a fixed pH, followed by separation of the solid catalyst from this solution, drying and …
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