Teses / dissertações sobre o tema "Homogenous catalysts"
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Ruiz, Botella Sheila. "The importance of ligand design for the development of supramolecular catalysts and ion receptors". Doctoral thesis, Universitat Jaume I, 2017. http://hdl.handle.net/10803/402550.
The present thesis is divided in two different parts. Part 1 is titled the importance of ligand design for the development of supramolecular catalysts. This part includes three different chapters: introduction chapter 1, chapter 2 and chapter 3. Chapter 1 shows a brief overview of the most interesting items related to supramolecular catalysis. In chapter 2 is described the synthesis and characterization of three different p-xylylbis-benzimidazolylidene iridium and rhodium complexes. Chapter 3 reports the synthesis, characterization and catalytic studies of different palladium, iridium and rhodium complexes, which are formed by N-heterocyclic ligands featuring different topologies, and some of them decorated with pyrene functionalities. The importance and influence of these ligands in the conformational and catalytic behaviour of the metal complexes is studied in detail, providing evidences of the effects produces due to non-covalent interactions such as π-π interactions. Part 2 is titled the importance of ligand design for the development of ion receptors. This part includes three chapters: introduction chapter 4, chapter 5 and chapter 6. Chapter 4 is a brief introduction of the most relevant aspects related to supramolecular host-guest chemistry. The approaches described in chapter 5 consist of two different strategies for the preparation of imidazole resorcinarene based cavitands for the recognition of anions or cations. Chapter 6 reports the synthesis of tris-azolium and tris-iodoazolium tripodal receptors for the recognition of anions. In both chapters (5 and 6) are studied the binding capabilities of the receptors towards several ions, showing the importance of the development in ligand design to improve the properties of the receptors.
Guo, Chris. "Alkane Oxidation Catalysis by Homogeneous and Heterogeneous Catalyst". Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/622.
Guo, Chris. "Alkane Oxidation Catalysis by Homogeneous and Heterogeneous Catalyst". University of Sydney. Chemistry, 2005. http://hdl.handle.net/2123/622.
Damian, Karen Serena. "Pd catalysed synthesis of phosphines for homogeneous catalysis". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/907.
Craig, Kim Meyer. "New concepts in catalyst design: homogeneous organometallic catalysts with tunable architectures". Thesis, University of Auckland, 2010. http://hdl.handle.net/2292/6114.
Gao, Tianyu. "Hétérogénéisation de catalyseurs homogènes à l'aide de matériaux à structures organiques covalentes". Electronic Thesis or Diss., Centrale Lille Institut, 2022. http://www.theses.fr/2022CLIL0016.
Heterogenization of homogeneous catalysts is an effective way to combine highactivity, selectivity and recyclability of catalysts. Covalent Organic Frameworks (COF) are promising organic porous materials that are worthy to be developed as host structures for the heterogenization of homogeneous catalysts, due to their high specific surface area, microporous structure, easy functionalization and high thermal stability. In this thesis, homogeneous phosphotungstic acid (HPW) is heterogenized via encapsulation into the interlayer spacing of 2D COF CIN-1. The heterogenized HPW@CIN-1 catalyst shows high catalytic activities and stability in acid-catalyzed reactions. Heterogenization of homogeneous Ru ions is achieved via tethering by diphenylphosphinobenzaldehyde ligand in the interlayer spacing of CIN-1. The obtained heterogenous Ru@CIN-1 catalyst shows high catalytic activity and stability in model reactions of amination and hydrogenation. In order to widen the application of Ru@CIN-1 catalyst, it has been pyrolyzed under inert atmosphere to obtain Ru supported over carbon nitride material. The obtained novel Ru@g-C3N4 material demonstrates a super performance in electrocatalytic water splitting. Homogeneous Fe(NO3)3 catalyst is heterogenized via grafting to hydroxyl-substituted bidentate 2D COF LZU1 (LZU1-OH). The obtained Fe@LZU1-OH catalyst shows high activity in oxidation model reactions comparable to the parent homogeneous catalyst at high stability
Richardson, John Michael. "Distinguishing between surface and solution catalysis for palladium catalyzed C-C coupling reactions: use of selective poisons". Diss., Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22704.
Schätz, Alexander. "Immobilization of homogeneous catalysts on nanoparticles and their application in semi-heterogeneous catalysis". kostenfrei, 2009. http://www.opus-bayern.de/uni-regensburg/volltexte/2009/1239/.
Martins, Tânia Isabel Quintas. "Continuous flow homogeneous catalysis using ionic liquid/supercritical fluid biphasic systems". Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/982.
Lummiss, Justin Alexander MacDonald. "Olefin Metathesis: Life, Death, and Sustainability". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32277.
Craythorne, Steven James. "Heterogenizing homogeneous hydrogenation catalysts". Thesis, Queen's University Belfast, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486059.
Jones, Rebecca S. "Carbon Dioxide as a Benign Solvent for Homogeneous Catalyst Recovery and Recycle". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/11641.
Müller, Ruben S. Ramon. "Homogeneous gold catalysts : development of applications for gold(I) catalysts bearing N-heterocyclic carbene ligands". Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2531.
Oh, Seokjoon. "Graphite-conjugated catalysts : bridging heterogeneous and homogeneous catalysts". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122714.
Cataloged from PDF version of thesis. Page 156 blank.
Includes bibliographical references.
This interconversion occurs via complex multistep, multielectron reactions, which can be carried out by either metallic heterogeneous or molecular homogeneous electrocatalysts. Metallic heterogeneous catalysts have a continuum of electronic states that distribute the redox burden of multielectron reactions, allowing for efficient catalysis. However, heterogeneous catalysts display a variety of active sites and local electronic structures, and are difficult to fine-tune at a molecular level. On the other hand, homogeneous catalysts allow a great degree of synthetic control over the catalytic active site. Moreover, the relative ease in spectroscopic characterization allows a mechanistic understanding of molecular catalysis at a level that is unattainable for heterogeneous catalysis. To bridge the advantages of both types of catalysts, we have developed a surface functionalization strategy for conjugating molecularly well-defined active sites to graphitic carbon surfaces.
First, I will discuss the preparation and characterization of two new types of conjugating N-heterocyclic linkages to graphitic carbon surfaces. This work presents a general method for characterizing modified carbon surfaces with molecular-level structural detail. Then, I will present the electrocatalytic carbon dioxide reduction activity of a graphite-conjugated rhenium catalyst, and compare its catalytic behavior to that of a molecular analog. Electrochemical and spectroscopic data show that graphite-conjugated catalysts do not behave identically to their molecular analogs, but rather show properties similar to that of metallic heterogeneous catalysts, providing a unique bridge between the worlds of heterogeneous and homogeneous catalysis.
Finally, in the appendix, I will present a chapter on the stability of graphite-conjugated linkages under electrochemical polarization, followed by a chapter on catalyzing the reduction of molecular pyridinium species using a graphite-conjugated rhodium catalyst.
by Seokjoon Oh.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Chemistry
Evans, P. L. "Ligand design for homogenous catalysis". Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376909.
Durrani, Jamie T. "Palladium catalysed asymmetric hydroxy- and alkoxycarbonylation of alkenes". Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/6276.
Adams, Nicholas James. "Studies in homogeneous catalysis". Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312264.
Downs, Emma. "An Investigation of Transition Metal Catalysts for Cyanohydrin Hydration: The Interface of Homogeneous and Heterogeneous Catalysis". Thesis, University of Oregon, 2014. http://hdl.handle.net/1794/18348.
2015-09-29
Nicol, Mairi. "Modification of polydienes via homogenous catalysis". Thesis, University of St Andrews, 1998. http://hdl.handle.net/10023/15183.
Groot, Debby de. "Dendrimers as homogeneous transition metal catalysts". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2001. http://dare.uva.nl/document/58731.
Desset, Simon L. "New strategies for the rhodium-catalysed aqueous-biphasic hydroformylation of medium chain alkenes". Thesis, University of St Andrews, 2009. http://hdl.handle.net/10023/842.
Cooper, Christine J. "Catalysts for stereoselective transformations". Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.548099.
Maddox, P. J. "Oxidative addition on homogeneous catalysis". Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379910.
Garland, Carl Sherman. "Redox promotion of homogeneous catalysis". Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257734.
La, Sorella Giorgio <1987>. "Supramolecular approaches to Homogeneous catalysis". Doctoral thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/8319.
Wang, Xia. "Artificial Photosynthesis : Carbon dioxide photoreduction and catalyst heterogenization within solid materials". Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLET025/document.
In the context of global warming and the necessary substitution of renewable energies (solar and wind energy) for fossil fuels, efficient energy-storage technologies need to be urgently developed. Recently, energy storage via the reduction of CO2 has seen renewed interest. Although reduction of CO2 into energy-dense liquid or gaseous fuels is a fascinating fundamental issue, its practical implementation in technological devices is highly challenging due to the high stability of CO2 and thus the endergonic nature of its transformation. Furthermore, the reactions involve multiple electrons and protons and thus require efficient catalysts to mediate these transformations.The objective of this thesis is to investigate different strategies for the storage of solar energy in chemical compounds, through visible-light-driven CO2 reduction. This thesis comprises of two main parts. After an introduction, the first part describes the investigation of homogeneous catalysts in combination with a photosensitizer, either separately or connected covalently. Due to the easily-tunable synthesis and facile characterization of molecular catalysts, homogeneous photosystems are more controllable and can give deep insight into product selectivity and mechanistic issues.With regards to future applicability, however, homogeneous catalysis often suffers from additional costs associated with solvents, product isolation and catalyst recovery, amongst other factors. The integration of molecular catalysts into solid platforms offers the possibility to maintain the advantageous properties of homogeneous catalysts while moving towards practical system designs afforded by heterogeneous catalysis. The second part of this thesis is therefore the immobilization of molecular catalysts within solid materials, namely MOFs and PMO. The ultimate goal of this thesis is to incorporate both catalyst and photosensitizer into the solid support
Grootboom, Natasha Denise. "Alkane oxidation using metallophthalocyanine as homogeneous catalysts". Thesis, Rhodes University, 2002. http://hdl.handle.net/10962/d1007794.
Shinde, Kiran. "Biodiesel production under ultrasound and homogeneous catalysts". Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/28233.
Biodiesel is obtained by transesterification reaction of triglycerides from vegetable oils or fats and a mono alcohol like methanol. This reaction is also known as alcoholysis. Ultrasound biodiesel production technique has recently emerged as a promising technology for synthesis of this alternative for fossil fuels. Ultrasound biodiesel production is based on the use of ultrasonic probes. By using this technique biodiesel production can be made on a large scale. Continuous ultrasonication technique can induce strong emulsion of alcohol and oil phases in a short time. Within very small residence time, high conversions are obtained in presence of different homogeneous catalysts. Therefore, it is necessary to solve the remaining challenges of biodiesel production, in terms of reactor design, catalyst recovery, cost and environment issues, in order to address the biodiesel production as a viable industrial technology. The previously studied biodiesel production technologies still show some challenges such as: methanol recovery issue, catalyst separation, reaction time, reaction temperature and oxide impurities in products. Therefore, there is still need to develop and modify the continuous biodiesel production technology. This work deals with the development of ultrasound biodiesel production. The original aspect of the present work conclusions is a vision of how ultrasound waves affect the transesterification reactions rates. Ultrasounds generate a fine emulsion of the biphasic system in the entire reactor volume. This will obviously affect interphase mass transfer. The catalytically active volume is however restricted to a small part of the reaction medium located in the immediate vicinity of the sonotrode probe. Within this volume fraction the extremely high reaction rate is very likely associated with the effects of cavitation. To increase the biodiesel production in presence of ethanol under ultrasound we tested the possible effects of minor methanol or other low vapor tension component additions on the accelerating phenomenon in triglycerides transesterification reactions due to ultrasounds. In the last part of the work we studied the transesterification reaction of canola oil with methanol and different types of catalysts using both mechanical stirring and ultrasonication reaction. The efficiency of mass transfer in the ultrasound field enhanced the higher rate of transesterification reaction as compared to stirring conditions. In case of propyl-2, 3 dicyclohexylguanidine and 1, 3- dicyclohexyl 2 n-octylguanidine (DCOG) as catalysts under ultrasound transesterification reaction we got noticeable TG conversion where as more than 80% regeneration of guanidine is possible from the reaction mixture by using silica cation exchanger columns. Keywords: ultrasound, transesterification, canola oil, FAME, sodium methoxide, sodium hydroxide, potassium hydroxide, Tetramethyl ammonium hydroxide, Guanidine, silica cation exchanger columns.
Wojcik, Karolina. "D-glucosamine as "green" substrate in synthesis of ligands for asymetric catalysis". Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00974873.
Funes, Ardoiz Ignacio. "Computational Chemistry for Homogeneous Redox Catalysis". Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/456826.
Esta Tesis Doctoral se ha centrado en el estudio computacional mediante metodología DFT (Teoría del funcional de la densidad) de reacciones redox catalizadas en fase homogénea. La primera parte versa sobre el estudio computacional de dos ciclos catalíticos de acoplamiento oxidativo. Este estudio dio con una de las claves en este tipo de reacciones, el efecto del oxidante externo. Demostramos en ambas reacciones como diferentes metales de transición podían colaborar para dar una reacción más eficiente y selectiva. Además descubrimos las claves para la regioselectividad en ambas reacciones. La segunda reacción fue estudiada en colaboración con el grupo experimental del profesor Frederic Patureau (University of Kaiserslautern). Por otro lado, la segunda parte de esta tesis se centra en el estudio teórico de la reacción de oxidación de agua catalizada por complejos de la primera serie de transición. Desarrollamos una nueva familia de catalizadores mononucleares de cobre con la colaboración experimental del grupo del profesor Antoni Llobet (ICIQ), descubriendo un nuevo mecanismo en la formación de enlace oxígeno-oxígeno, el ataque nucleófilo del agua mediante la transferencia de un electrón (SET-WNA). Tras esto extendimos este mecanismo a otros sistemas de cobre y de rutenio, redefiniendo el contexto mecanístico para esta reacción en catálisis homogénea. Esta tesis, por tanto, proporciona una profunda base mecanística sobre el estudio de importantes reacciones redox mediante química computacional a través de los métodos DFT.
This Doctoral Thesis is focused on the computational study by DFT methodology (Density Functional Theory) of homogeneous redox catalized reactions. The first part describes successfully the mechanism of two different catalytic cycles of oxidative coupling reactions. This study found out the explanation about one of the challenging questions on the field, the key role of the external oxidant. We demonstrated the cooperation between different transition metals is essential to catalyze the reaction efficiently and with good selectivities. Additionally, we explained also the regioselectivity of both reactions, in very good agreement with the experimental results. The second reaction was studied in collaboration with the experimental group of professor Frederic Patureau (University of Kaiserslautern). On the other hand, the second part of the thesis is focused on the theoretical study of water oxidation reaction catalyzed by first-row transition metal complexes. Firstly, we developed a new family of mononuclear copper complexes in collaboration with the experimental group of professor Antoni Llobet (ICIQ), discovering a new mechanism for the oxygen-oxygen bond formation step, the water nucleophilic attack. single electron transfer (SET-WNA). From this point, we extended the new mechanism to other catalytic systems based on copper and ruthenium, redefining the mechanistic scenario for the homogeneous catalytic version of this reaction. Therefore, this thesis provides a deep theoretical knowledge abour the homogeneous redox catalysis mechanisms by DFT calculations.
Stemp, Michael C. "Homogeneous catalysis in alkaline water electrolysis". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0019/MQ45844.pdf.
Taylor, Russell Alan. "Hydrogen bonding effects in homogeneous catalysis". Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500138.
Mitsui, Kazuhiko. "Dendritic Effects in Homogeneous Asymmetric Catalysis". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1245200227.
Patil, R. P. "Studies in homogeneous catalysis: carbonylation reactions". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1990. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3026.
Kieffer, Raphaëlle. "Développement de nouveaux catalyseurs pour la dépolymérisation de la lignine par voie d’oxydation". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10124/document.
Lignin is one of the most abundant biopolymers on earth. It is issued from plants and represents the largest source of aromatics in biomass. Projects aiming at depolymerizing lignin to obtain value-added small molecules for the chemical industry are more and more developed due to the high potential of this bio-resource. The goal of our project was to develop a new catalytic system for the depolymerization of lignin. We have been interested in designing new homogeneous and heterogeneous catalysts based on the known structure of the Fe(TAML) complex. We have studied their reactivity and stability under oxidative catalysis conditions, and have compared them to the characteristics of the existing Fe(TAML). To do so, the catalysis study has been realized on lignin small model molecules to avoid the analytical problems related to a polymer backbone. In a first hand, we will present the strategy of functionalization of the known TAML ligand to design new complexes to be grafted on a silica support. In a second hand, we will talk about the results of oxidative catalysis in homogeneous and heterogeneous conditions, and the influence of the ligand structure change on the activity of the catalysts
Dreimann, Jens M. [Verfasser]. "Process Intensification in Homogeneous Catalysis - Catalyst Recovery via Thermomorphic Solvent Systems and Organic Solvent Nanofiltration / Jens M. Dreimann". München : Verlag Dr. Hut, 2017. http://d-nb.info/1139538349/34.
Dreimann, Jens [Verfasser]. "Process Intensification in Homogeneous Catalysis - Catalyst Recovery via Thermomorphic Solvent Systems and Organic Solvent Nanofiltration / Jens M. Dreimann". München : Verlag Dr. Hut, 2017. http://d-nb.info/1139538349/34.
Rahman, Mohd Basyaruddin Abdul. "Energy dispersive EXAFS studies on homogeneous metal catalysts". Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285766.
Monterio, Mario G. Kool. "Polymerization Studies using homogeneous and supported metallocene catalysts". Thesis, University of Manchester, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.642948.
Thevenon, Arnaud. "Homogeneous catalysts for the synthesis of oxygenated polymers". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:25c312d1-11c9-4180-a62d-b87a41f521c0.
Nair, V. S. "Hydroformylation of olefins using homogeneous and biphasic catalysts". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1999. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2952.
Lamb, Gareth W. "Phosphine modified rhodium catalysts for the carbonylation of methanol". Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/574.
Borole, Y. L. "Studies on catalysis and kinetics of hydroformylation reactions by homogeneous catalysis". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2004. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2889.
Motika, Stephen. "Diversifying Homogenous Au(I)-Catalysis through New Reaction Discovery". Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6911.
Segarra, Maset Maria Dolores. "Switchable and tunable ligands for homogeneous catalysis". Doctoral thesis, Universitat Rovira i Virgili, 2010. http://hdl.handle.net/10803/9110.
En la primera parte se describe el desarrollo de ligandos fosfina que incorporan en su estructura la unidad azobenceno, la cual puede presentar dos isómeros estructuralmente diferentes. Se estudia el efecto de la isomerización sobre diferentes reacciones catalíticas.
En la segunda parte se utilizan interacciones supramoleculares para inducir quiralidad sobre una difosfina biarílica proquiral. Se estudian los complejos supramoleculares formados, así como su efecto en catálisis asimétrica.
En la última parte se describe la obtención de ligandos trans-bidentados. Se sintetizan fosfininas y piridinas monodentadas que forman ligandos bidentados al asociarse mediante enlaces de hidrógeno. Adicionalmente, se incorpora la unidad azobenceno en la estructura de fosfininas y piridinas bidentadas para conseguir la coordinación trans mediante la isomerización del doble enlace.
This thesis describes the development of new ligands with unusual properties to be applied in homogeneous catalysis. Three strategies were envisaged to obtain the the new ligand systems. Accordingly, the thesis is divided in three parts.
The first part describes the design of phosphine ligands that include in their structure the azobenzene moiety, which occurs in two structurally different isomers. The effect of the isomerization on several catalytic reactions was studied.
The second part presents the use of supramolecular interactions to induce chirality in a prochiral biaryl diphosphine. The formation of the supramolecular complexes and the effect on asymmetric catalysis were also investigated.
Frew, Jamie J. R. "Novel bulky fluorinated ligands for homogeneous catalysis". Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/852.
Kelly, Keith. "Homogeneous catalysis routes to heat resistant polymers". Thesis, University of East Anglia, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257476.
Gibbard, Jonathan Peter. "Homogeneous catalysis for the selective hydrogenation of nitroalkenes". Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248125.
Crawford, Luke. "Mechanistic insights into enzymatic and homogeneous transition metal catalysis from quantum-chemical calculations". Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7818.
Zafar, Muhammad Naveed. "Development of new ligands for homogeneous transition metal catalysts". Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/7287.