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1,2,3-(NH)-triazoles its metal-free synthesis and application as ligands in transition metal catalysis /Sengupta, Sujata. January 2010 (has links)
Thesis (Ph. D.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains xii, 328 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-91).
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An investigation of iron supported on titania as a catalyst for ammonia synthesisSantos, Jeannette. January 1982 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 135-141).
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Studies of silica supported metal catalystsBrown, Carole Elizabeth. Stiegman, Albert E. January 2006 (has links)
Thesis (M.S.)--Florida State University, 2006. / Advisor: Albert E. Stiegman, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains xiii, 83 pages. Includes bibliographical references.
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Alcohols conversion over transition metal based catalytsNdebele, Mthobisi Sbonelo January 2018 (has links)
Submitted in fulfillment of the requirements for the Master of Engineering Degree, Durban University of Technology, Durban, South Africa, 2018. / Ethanol and butanol obtainable through fermentation of lignocellulose biomass have become promising alternative feedstock for production of fuels as they are biodegradable and sustainably regenerated via the photosynthesis cycle. The properties of hydrocarbons produced through alcohol conversion closely resemble those of gasoline. Catalytic systems are reported to play a vital role during alcohol conversion to hydrocarbons. In this study ethanol and butanol were used as a feedstock for production of hydrocarbons over Fe, Zn and Ni catalyst systems supported on zeolite ZSM-5 (Zeolite Socony Mobil-5) and activated carbon (AC).
X- Ray Diffraction (XRD), Scanning Electron Microscope (SEM) coupled with Energy- dispersive X-ray spectroscopy (EDS) and Brunauer, Emmet, and Teller (BET) analyses were employed for catalyst characterization. XRD patterns confirmed the success of metal doping on ZSM-5 and activated carbon supports. Major peaks at 7.96° and 23.97° corresponding to ZSM-5 crystals were observed in ZSM-5, and AC was found to be amorphous. Impregnation with metals reduced the crystallinity of ZSM-5 supported catalysts. Whereas SEM analysis showed that catalysts supported on ZSM-5 exhibited irregular shapes and catalyst supported on activated carbon exhibited disordered structures. The BET analyses confirmed that the surface areas of promoted catalysts decreased after metal doping.
Evaluation of the catalysts were carried out in a ½ inch stainless steel reactor at 400 °C and atmospheric pressure with a weight hourly space velocity (WHSV) of 2.5 h-1 (g feed)/ (g catalyst). The ZSM-5 support performed better than activated carbon support. More than 90% conversion was achieved over catalysts supported on ZSM-5. Production of hydrocarbons over catalysts supported on activated carbon were as a result of the active component. Conversion of feedstock was observed to produce more benzene, toluene and xylene (BTX) compounds with an increase in butanol content. 100% conversion was achieved with pure butanol and not more than 99.86% conversion was achieved with pure ethanol.
Catalyst systems supported on HZSM-5 and activated carbon were successfully synthesised. Ethanol, butanol and ethanol-butanol mixtures were successfully converted to liquid hydrocarbons and the conversion was greater than 90%. On the promoted catalysts, production of BTX were suppressed and various metals were observed to perform differently. / M
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Supramolecular assemblies of bioinorganic complexes formed via reaction of (S)-proline with nickel clusters on Au(111)Green, Riho Thomas Seljamae January 2014 (has links)
Considerable research over several decades has been directed at the development of heterogeneous enantioselective hydrogenation catalysts via the chiral modification of Ni catalysts by chiral molecules such as α-hydroxy acids and α-amino acids. Some of these systems have proved to be very successful yielding catalysts achieving very high enantioselectivity. However, the modified surfaces display relatively poor stability under catalytic conditions, so there is a demand to produce more robust chiral architectures for application in this area of catalysis. The formation of metal organic coordination networks on surfaces has been the subject of intensive study in the last decade. This thesis reports the formation of metal organic structures via the reaction of (S)-proline with nanoscale Ni islands grown on Au(111). Initially, (S)-proline was studied Au(111) using low temperature scanning tunnelling microscopy (LT-STM), XPS and high resolution electron energy loss spectroscopy (HREELS). Adsorpton of (S)-proline at 300 K resulted in the formation of a mixture of the zwitterionic and anionic forms of proline. The former species condensed into ordered arrangements at 77 K giving a structure very similar to one crystal plane of solid proline. Proline species were relatively weakly bound and the vast majority of adsorbed proline desorbed by 370 K. (S)-proline adsorption was examined on Ni/Au(111) over a range of Ni coverages from 0.05 ML up to >1.0 ML STM, XPS, HREELS and DFT calculations. (S)-proline was found to oxidise Ni from the edges of the Ni islands producing nickel prolinate species. Five distinct classes of supramolecular assemblies were produced depending on Ni coverage and annealing temperature. The nature of each of these structures is described. It is concluded that one assembly is built up from Ni(prolinate)₂ (square planar) complexes, three of the assemblies have a fundamental building block consisting of a Ni(prolinate)₃ octahedral complex and the final structure, observed at high annealing temperatures, is constructed from oligomerized proline species. The interaction of the prochiral reagent, methyl acetoacetate, with some of these supramolecular assemblies is reported.
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Study on osmium and manganese complexes of chiral binaphthylic tetradentate ligands and their application to asymmetric epoxidationof alkenes何振華, Ho, Chun-wah. January 1994 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
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Homogeneous gold catalysts : development of applications for gold(I) catalysts bearing N-heterocyclic carbene ligandsMüller, Ruben S. Ramon January 2011 (has links)
Recently established as an excellent activator for π-systems, efforts made in gold chemistry have increased enormously, resulting in a new ‘Gold Rush’ in chemistry. This thesis is a small contribution to it. There are two main aspects dominating the following chapters: gold catalysts bearing N-heterocyclic carbenes (NHCs) as supporting ligand, and H₂O assisted catalysis. The initial motivation for the presented work was to specifically demonstrate the potential of [(NHC)AuCl] as suitable catalysts for both known and new organic transformations and to establish these commercially available catalysts in gold chemistry, a field currently dominated by phosphine bearing gold complexes. Water mediated catalysis became the next repeatingly occurring aspect of this thesis by pursuing this initial aim and finding water as a useful solvent or agent, respectively. Various useful applications for gold-NHC complexes are presented, starting with the Meyer-Schuster rearrangement of propargylic alcohols as a continuation of the work realized with propargylic acetates by the Nolan group in early investigations on gold catalysts. Next, a study on alkyne hydration is presented with focus on low catalysts loadings to establish gold catalysts as a powerful choice for such a highly relevant reaction. The catalytic system is then advantageously adapted to a silver-free variation, still active at low catalyst loadings and with further mechanistic insight. Inspired by gold activation of alkynes, a gap of reactivity in gold catalysis is closed by a successful demonstration of nitrile hydration, a functionality previously thought to be inert towards gold activation. In this context, formation and role of dinuclear hydroxy-bridged gold complexes is investigated highlighting these complexes as a possible resting state of gold complexes in the presence of water. Next, the formation of furanones via alkoxylation/lactonization of propargylic propiolates is presented, an observation initially made when exploring the scope of the Meyer-Schuster rearrangement. The dissertation finally closes with the gold-catalyzed formation of amides, this time however achieved from aldoximes reacting via dehydration/hydration mechanism.
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An ethanol conversion study over titania supported catalystsChen, Yao-Kuan January 1992 (has links)
A thesis Submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, for the Degree of Master of Science.
Johannesburg, December 1992. / The ethanol conversion to hydrocarbons over acidic catalysts proceeds with high activity and selectivity and has hence generated considerable interest. In this thesis an investigation of the use of a range of supports, loaded with metals as potential catalysts for the ethanol transformation reaction, is reported. In particular, Ti02 was investigated as a support and the addition of a secondary component to the catalyst was examined with respect to product selectivities. [Abbreviated Abstract. Open document to view full version] / AC2017
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A user-friendly synthesis of aryl arsines and phosphines.January 2001 (has links)
by Lai Chi Wai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 63-68). / Abstracts in English and Chinese. / Table of Contents --- p.i / Acknowledgments --- p.iii / Abbreviations --- p.iv / Abstract --- p.v / Chapter Chapter 1 --- General introduction / Chapter 1.1 --- Background of phosphines and arsines ligands in metal catalysis --- p.1 / Chapter 1.2 --- Electronic effect of phosphines and arsines ligands in metal catalysis --- p.2 / Chapter 1.3 --- Synthesis of Aryl Phosphines --- p.7 / Chapter 1.4 --- Synthesis of Aryl Arsines --- p.9 / Chapter 1.5 --- The objective of this work --- p.11 / Chapter Chapter 2 --- Palladium catalyzed phosphination of aryl triflates / Chapter 2.1 --- Synthesis of aryl triflates --- p.12 / Chapter 2.2 --- Palladium catalyzed phosphination of aryl triflates --- p.15 / Chapter 2.3 --- Mechanistic studies of phosphination --- p.19 / Chapter Chapter 3 --- Palladium catalyzed arsination of aryl triflates --- p.22 / Chapter 3.1 --- Solvent and catalyst screening in palladium catalyzed arsination --- p.23 / Chapter 3 2 --- Stoichiometry of triphenylarsine --- p.24 / Chapter 3.3 --- Temperature effect of arsination --- p.25 / Chapter 3.4 --- Results of palladium catalyzed arsination --- p.26 / Chapter 3.5 --- Mechanistic studies of arsination --- p.28 / Chapter Chapter 4 --- Green chemistry approach 一 solventless phosphination and arsination / Chapter 4.1 --- Introduction to green chemistry --- p.30 / Chapter 4.2 --- Results of solventless phosphination --- p.31 / Chapter 4.3 --- Results of solventless arsination --- p.33 / Conclusion --- p.36 / Experimental --- p.37 / Reference --- p.63
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Atom transfer radical polymerizationDing, Shijie. January 2006 (has links)
Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 20, 2007). Includes bibliographical references.
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