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Showing 1 to 20 of 32 for “"Palladium catalysts"”.
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Preparation and Characterization of Palladium Catalysts
… critical need for improved combustion-oxidation catalysts to reduce emissions of toxic volatile organic compounds (VOCs) emitted from exhaust gas of gasoline combustion in automotive vehicles. Materials and systems currently available, such as the three way catalytic converter (TWC), have low …
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The development of palladium-catalysts for organic synthesis
… ability in the high activity of catalysts derived from ligands of this type. Further, when the aryl bromide becomes too hindered, an interesting C-H bond functionalization-cross-coupling sequence intervenes to provide product in high yield. Chapter 2. The direct transformation of …
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Decomposition of methanol into synthesis gas over supported palladium catalysts
Includes bibliographical references (pages 87-92).
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Oxidation of Carbon Monoxide Over Ceria and Alumina Supported Palladium Catalysts
<p>Palladium catalysts on both Al2O3 and CeO2, supports were studied for efficacy in low temperature carbon monoxide oxidation. Calcination temperatures were varied between 500-900°C for alumina supported catalysts and shown to have no significant difference in activity. X-Ray Photoelectron …
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Synthesis, Activation and Catalytic Activity of N-Heterocyclic Carbene Bearing Palladium Catalysts
… complexes. The use of those complexes as pre-catalysts in cross-coupling (Suzuki- Miyaura, Buchwald-Hartwig) and related (catalytic dehalogenation, £-ketone arylation) reactions is also discussed. A comparison of the activity of a variety of (NHC)Pd complexes as pre-catalysts for …
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Synthesis, Characterization and Activity of Palladium Catalysts on the Dual Support of Cerium and Aluminum Oxides
… under lean conditions were investigated. The catalysts were prepared by a combination of impregnation, slurry and vortexing methods. The catalysts had 4.7 wt.% Pd and 10.7 wt.% Ce based on inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The catalysts were …
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Understanding the effects of promoters on the direct synthesis of hydrogen peroxide over supported palladium catalysts
… the formation of H2O2 on most transition metal catalysts which lowers the H2O2 selectivity of direct synthesis. Hence, significant research has been directed towards improving H2O2 selectivity through various methods (addition of promoters, alloying Pd with other transition metals). The addition …
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Late transition metal catalyzed C-N and C-C bond forming reactions
New methods for the palladium-catalyzed amination of aryl halides are described. Key to these is the development of new catalysts and reaction conditions for these transformations. Initially, P(o-tol)3 ligated palladium catalysts were investigated but gave way to systems that used chelating …
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Polymerization and Isomerization of Olefins using Late-Transition Metal Complexes
… serve as efficient olefin polymerization catalysts. The mechanism of α-diimine-palladium and nickel catalyzed olefin polymerization is well understood. By understanding the fundamental steps of olefin polymerization, catalysts can be rationally designed to achieve a polymer with desired …
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Mononuclear and Dinuclear Complexes of Allylated alpha-Diimines as Catalysts for the Polymerization of Ethylene
… the goal of this project to synthesize dinuclear catalysts that provide two different active sites for the oligomerization and polymerization of alpha-olefins, especially ethylene. The plan of synthesis involves precursors consisting of a diimine moiety coordinated to a late or early transition …
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Palladium-catalyzed C-C, C-N and C-O bond formation
… proper choice of ligand and reaction conditions. Palladium catalysts supported by bulky, monodentate phosphine ligands with a biaryl backbone or the bidentate ligand, Xantphos, effectively promote the formation of ca-aryl carbonyl compounds. Base-sensitive functional groups are better tolerated …
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Development of N-Heterocyclic Carbenes as Organic Catalysts and Efficient Ligands in Palladium Mediated Transformations
… that end, NHCs represent an important class of catalysts and catalyst modifiers which mandate continued research efforts. Prospective applications of processes catalyzed by NHCs and NHC-metal catalysts provide a strong impetus to develop them and related methodologies. This dissertation focuses …
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Catalytic Reduction of NO and N2O with Hydrogen in Water by Polymer-Protected Palladium Nanoparticles
… gases to harmless dinitrogen by nanoparticulate palladium catalysts is a promising method for treating NO and N2O formed in water. However, creating a better understanding of the method of catalytic activity and corresponding selectivity is critical for developing an optimal process. We have …
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Selective hydrogenation of α,β[alpha,beta]-unsaturated aldehydes towards clean synthesis over noble metal catalysts in mass transfer efficient three phase reactors
… using both in-house-prepared and commercial palladium, platinum and ruthenium catalysts was carried out in stirred tank reactors and cocurrent downflow reactors in order to study the kinetics and mass transfer characteristics and the selectivity towards the corresponding desired product, …
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New methodologies and approaches to reaction discovery in transition metal catalysis
… alkyl electrophiles has been developed. Simple palladium catalysts enable the coupling of aryl boronate esters formed from iridium-catalyzed C-H borylation to be coupled with various allylic halides, allylic carboxylates and benzylic halides. Nickel catalysts bearing diamine or phenanthroline- …
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Palladium Catalyzed Hydrodechlorination of 4-Chloroanisole in Phosphonium Ionic Liquids
… as a model compound. In this fundamental study, palladium-catalyzed dechlorination of chloroanisole was studied in ionic liquids (ILs), where the catalyst was expected to be more stable than in methanol, the previously used solvent. This thesis describes the hydrodechlorination efficacy and …
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Catalytic Process for the Conversion of Synthesis gas to Ethanol for Use as an Alternative Fuel
… coal, natural gas and biomass. Rhodium-based catalysts have been found to be the most active/selective for higher alcohols. However, the literature shows that the yields of C2+-alcohols that can be achieved with current catalysts, even the most active/selective, are not practical, typically …
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Palladium-catalyzed PMHS reductions of imines
… the PMHS and KF concentrations, a screening of palladium salts was conducted. This screening proved that Pd(OAc)<sub>2</sub> is the most efficient catalyst for these reductions.Chemoselective reductions of aromatic imines were achieved in the presence of nitriles, nitro, fluoride, and chloride …
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