Дисертації з теми "Catalyseurs – Surfaces"
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Norsic, Sébastien. "Traitement chimique des surfaces des alumines silicées : application à l'hydrocraquage." Poitiers, 2006. http://www.theses.fr/2006POIT2314.
The aim of our work was to find new hydrocracking catalysts allowing a selective transformation of vacuum distillates into gas oil. Hydrocracking catalysts are bifunctional, associating a metallic function (hydro-dehydrogenating) and an acidic function (isomerizing). The vacuum distillates containing nitrogen and sulphur compounds, the hydro-dehydrogenating function will be provided by metal sulphides. On the other hand, if gas oil is the desired product, the acid function must be fairly strong. The most currently used catalysts are sulphides of Ni and W deposited on silica-alumina. We chose in this work to use a little different support : silicated aluminas, and to study the effect of heat treatments of this support, calcination or steaming, on the activity and the selectivity for hydrocracking of the sulphided catalysts. Calcination or steaming of silicated alumina brings important modifications of surface and pore volume, but do not modify the characteristics of the solid. In addition, these treatments, and in particular the steaming, create new Brönsted acid sites on the surface. The isomerizing activity of the corresponding catalysts is higher, and consequently their activity in hydrocracking is also higher. Indeed we observed that on these catalysts, the rate limiting step of hydrocracking was the acidic step. At the difference of what is generally observed, this increase in activity is not accompanied by a decrease in selectivity. Thus, the sulphided NiW/silicated alumina catalysts could be excellent industrial catalysts for hydrocracking. We also showed that it was possible to protect the acid sites of silicated alumina during the impregnation by nickel and tungsten, by blocking these sites by adsorption of pyridine. Unfortunately, the presence of pyridine considerably harms the formation of the sulphided phase, which makes the catalysts not very efficient in hydrocracking
Tougerti, Asma. "Elaboration de catalyseurs MoOx/Al2O3 : une approche science des surfaces en phase aqueuse." Paris 6, 2010. http://www.theses.fr/2010PA066137.
Ionescu, Andrei-Radu. "Modélisation des catalyseurs d'hydrodésulfuration : étude théorique des interactions entre le support et la phase active." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11023.
Herry, Soazic. "Étude de l'activation de catalyseurs d'hydrodésulfuration des gazoles préparés par modification du précurseur oxyde." Lille 1, 2006. http://www.theses.fr/2006LIL10160.
The presence of heteroatoms such as sulphur is an atmospheric pollutant because of its combustion products. 2005 is important year with the application of Euro4 regulations, in the European Union, which allowed 50 ppm of sulphur in gasoline and diesel and in 2009 this will decrease to 10 ppm. This implies an optimization of HDS process as well as the improvement of HDS catalysts. One of way of study to improve HDS catalysts is to add organic compounds in the preparation of catalysts. The purpose of this work is to understand the role of these molecules on the oxidic precursors, on the activation step and on the active phase morphology. An activation study has thus been done, in both gas and liquid phases which completed by physico-chemical characterizations, and showed the main role of organic compounds. The characteristic evolution of metals during sulfidation induces an optimization of the active phase morphology which is in correlation with the improvement of the catalytics performances
Marion, Ronan. "Catalyse supportée en flux continu utilisant des feutres de carbone de grande surface spécifique." Rennes 1, 2011. http://www.theses.fr/2011REN1S130.
This work is about the synthesis of new copper and ruthenium complexes containing tripodal ligands for application in continuous flow catalysis. These catalysts have been tested in oxidation reactions. A family of N-tripodal ligands has been prepared to determine the influence of several parameters on the catalytic activity such as steric effects, basicity or electronic effects of the substituants. Moreover, these ligands have a functionalized arm, which will be to attach the complexes onto the support. Copper complexes have been tested in homogeneous catalysis and then in continuous flow catalysis in a catechol oxidation reaction to study the influence of their immobilization on their catalytic activity. Once the determining factors in homogeneous medium were identified, a covalent grafting process on graphite felt has been set up. By electrochemical reduction of diazonium salts, a homogeneous and fast functionalization of the graphite felt has been achieved, allowing the chemical attachment of the complexes with volume concentrations around 10-8 mol. Cm-3. Then, continuous flow catalysis has been realized showing better catalytic activities than in homogeneous medium. Studies about the stability and the influence of the chain nature and length have also been performed. A preliminary study on ruthenium catalysts provided the synthesis of a new complex containing a N-tripodal ligand
Bara, Cédric. "Catalyseurs d'hydrotraitement à base de Mo supporté sur alumine : genèse de la phase active et effet de support par une approche science des surfaces." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066332/document.
The objective of this work was to develop a surface science approach to study the support effect on the genesis and structure of the active phase (molybdenum sulfide) on alumina supported Mo based hydrotreating catalysts supported on alumina which are used for petroleum refining. The originality of the work lies in the aqueous phase metal precursor deposition (molybdates) according to two synthetic routes (equilibrium adsorption and impregnation) on α alumina single crystals (γ alumina surrogate) with 4 different orientations (C (0001), R "(1" ¯("1" ) "02)" , A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" ). The combination of several physico-chemical characterization techniques (XPS, AFM, TEM, EXAFS) has shown that the surface structure of each crystal orientation governs the strength of metal/support interaction in the oxide state and thus the sulfidation degree and size of the sulfide active phase nanoparticles. This sulfide phase has been associated to a type I (strong metal/support interactions, lower sulfurability) for the R "(1" ¯("1" ) "02)" plane and to a type II (weaker metal/support interactions and better sulfurability) for C (0001), A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" planes. In addition, EXAFS results suggest a predominantly basal orientation of the sulfide phase on the C (0001) plane while a random orientation is highlighted on the other faces. The surface structural analogies between α and γAl2O3 polymorphs allows us to transpose these results to the industrial support (γ-Al2O3) and hence, to conclude that a proper control of the industrial support morphology constitutes a way to tune the genesis of the sulfide phase and improve the performances of hydrotreating catalysts
Barthe, Philippe. "Etude des effets du broyage et de l'addition de catalyseurs sur la réactivité d'un coke de charbon de Freyming." Lyon 1, 1987. http://www.theses.fr/1987LYO10533.
Carlier, Eric. "Elaboration et caractérisation de catalyseurs par greffage de polymères fonctionnalisés sur silices poreuses : tests de l'activité catalytique." Lyon 1, 1990. http://www.theses.fr/1990LYO10225.
Weissmann, Martin. "Modification de supports carbonés pour catalyseurs de pile à combustible par greffage de molécules à propriétés spécifiques." Poitiers, 2009. http://theses.edel.univ-poitiers.fr/theses/2009/Weissmann-Martin/2009-Weissmann-Martin-These.pdf.
The modification of carbon substrates by chemical functions significantly affects the surface properties of the material. These changes can be carried out by different methods: oxidation of the support, or grafting of molecules by reduction of a synthon. This last method seems more attractive because it helps to maintain the integrity of the support. The realization of grafted layers on carbon surface is carried out by reduction of diazonium or iodonium ions. This reduction results in the formation of radicals, which react with carbon surface to form a covalent bond. This method allows grafting a large variety of molecules; by selecting appropriate terminal groups it is possible to change different characteristics of the active layer of PEMFC electrodes, such as the hydrophobic / hydrophilic properties, platinum / support interactions and ionic conductivity. In this context, thiophenol grafted layers were realized to strengthen the anchorage of platinum nanoparticles on carbon support, limiting the migration of nanoparticles in course of sintering process. Carbon functionalized with benzenesulfonic acid groups and trifluoromethylbenzene groups were used to adjust the wettability of active layers, in order to improve water management in fuel cells. Grafted layers of alkynyl groups with ionic end functions could also be performed to confer ionic conductivity (protons or hydroxyls) to the catalyst support, in order to improve the use of catalyst in fuel cell electrodes
Rosal, Iker Del. "Modélisation de nanoparticules produites par voie organométallique et de catalyseurs greffés : structure, spectroscopie, réactivité." Toulouse 3, 2009. http://thesesups.ups-tlse.fr/1272/.
The work presented in this PhD manuscript concerns the study of surface chemistry and it is based on two questions asked by different experimental research groups. These questions cover different areas of surface chemistry, their answer would lead to a better understand the interactions occurring on these surfaces. This work is divided into two parts, each of which are based on the following issues: In which positions are the hydrogen atoms coordinated on the surface of ruthenium nanoparticles and which effect have the ligands on these atoms? It is of great interest in materials science to be able to control the size, shape and composition of nanoparticles (NPs) during their synthesis process. Their physico-chemical properties, comprised between those exhibited by small molecular compounds and the bulk, are one of the best advantages of these NPs. The NPs have an extremely rich surface chemistry, relatively little studied, that may influence both their chemical and physical properties. In this study, we are particularly interested in hydrogen atoms that play a key role in both the size and the shape of the NPs. However, their coordination mode remains unknown. To answer this first question, the NPs were modeled by two limit systems : small clusters and periodic surfaces. The study of these two systems allowed us, through a theory / experiments comparison of several spectroscopic data such as proton, deuterium NMR and infrared data to determine the most likely coordination mode of these hydrogen atoms and the effect of ligands on them. How organometallic catalysts are they grafted on a silica surface during catalytic supported reactions and which is the impact of the grafting mode on their reactivity ? The importance of catalysis both from an economic perspective (industrial) and environmental perspectives, requires the use of more efficient catalysts. One approach to achieve this goal is to have a better distribution and definition of active sites involved in heterogeneous catalysis process. One possibility to achieve this control is the use of supported catalysis. However, a prerequisite for this type of catalysis includes precise knowledge of the different types of interactions existing between the catalyst and its support. However, in the case of a lanthanide catalyst grafted on silica surface, the grafting mode remains unknown. As in the previous study, there are two methods to address this problem: either by a periodic approach, either by a molecular approach. Several different considerations led us to choose a molecular approach to conduct this study. For that purpose, we have created a molecular model that represents as accurately as possible the silica surface. The grafting reaction was then studied on this model, giving rise to different grafting modes, which are in accordance with the experimental data. Finally, a comparison between different catalytic reactions taking place with a metallocene lanthanide complex and the grafted catalyst above described has also been undertaken. Throught this investigation we could compare the reactivity of these two systems and determine the role of surface on the catalyst reactivity
Courthéoux, Laurence. "Préparation, mise en forme et évaluation des catalyseurs destines à la petite propulsion spatiale : décomposition du nitrate d'hydroxylammonium." Poitiers, 2004. http://www.theses.fr/2004POIT2279.
The control of the attitude of the satellites is due to small thrusters using the catalytic decomposition of a monopropellant. The high toxicity of hydrazine, used as monopropellant, induces high costs and then its replacement by a less toxic product is of current interest. The most studied monopropellant for this purpose corresponds to aqueous solutions of hydroxylammonium nitrate (HAN, NH3OH+NO3-) and fuel. Nevertheless, the use of such mixtures involves drastic conditions due to the high temperature reached during the decomposition (up to 1400 ʿC). Therefore, the catalytic activity at low temperature associated with a high thermal stability of the catalyst is a critical parameter for the future development of a new engine. Platinum supported on Si-doped alumina displays a good activity for this reaction. The Si-doped, powder or shape formed, alumina (aerogel or xerogel) are obtained by sol-gel procedure and are stable at high temperature (1200 ʿC, 5 h); the Pt/Al2O3Si catalysts are prepared by impregnation or by sol-gel method. The characterization before and after reaction by XRD, TEM, SEM and BET measurements display the homogeneity of materials prepared by impregnation on xerogel support. Moreover, the decomposition of the monopropellant begins at ambient temperature for these materials, which remain active in water and during 30 injections. Furthermore, the products formed during the reaction are followed with a mass spectrometer. A model is also proposed to describe the evolution of the active phase during the reaction
Tountian, Dihourahouni. "Hydrogénation électrocatalytique : effet de la conductivité et de la fonctionnalisation du support des nanoagrégats métalliques, utilisation du dioxyde d’étain comme support." Strasbourg, 2009. https://publication-theses.unistra.fr/public/theses_doctorat/2009/TOUNTIAN_Dihourahouni_2009.pdf.
The electrocatalytic hydrogenation (ECH) is a heterogeneous catalysis in which the nature of the electrode material is of high importance. New composites electrocatalysts (conductor and non-conductor) of palladium nanoparticles supported on tin dioxide were prepared by three different methods for phenol and cyclohexanone ECH. The results presented in this thesis show that the conductivity of the electrode material is an important factor in the ECH process. When the support material is conductor, there is an effective production of chemisorbed hydrogen by simultaneous polarization of all the metallic nanoparticles which contributes to greater efficiency of hydrogenation. Also, the ECH is pH dependent and this dependency is reflected by the variation in molecular species in solution and their adsorption on the electrode. The in situ functionalization of electrode materials by carboxylic acids with different side chains allowed controlling the adsorption step (rate-determining step) and thus modulating the efficiency of hydrogenation. This result opens up promising prospects for selective and enantioselective hydrogenation
Bara, Cédric. "Catalyseurs d'hydrotraitement à base de Mo supporté sur alumine : genèse de la phase active et effet de support par une approche science des surfaces." Electronic Thesis or Diss., Paris 6, 2015. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2015PA066332.pdf.
The objective of this work was to develop a surface science approach to study the support effect on the genesis and structure of the active phase (molybdenum sulfide) on alumina supported Mo based hydrotreating catalysts supported on alumina which are used for petroleum refining. The originality of the work lies in the aqueous phase metal precursor deposition (molybdates) according to two synthetic routes (equilibrium adsorption and impregnation) on α alumina single crystals (γ alumina surrogate) with 4 different orientations (C (0001), R "(1" ¯("1" ) "02)" , A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" ). The combination of several physico-chemical characterization techniques (XPS, AFM, TEM, EXAFS) has shown that the surface structure of each crystal orientation governs the strength of metal/support interaction in the oxide state and thus the sulfidation degree and size of the sulfide active phase nanoparticles. This sulfide phase has been associated to a type I (strong metal/support interactions, lower sulfurability) for the R "(1" ¯("1" ) "02)" plane and to a type II (weaker metal/support interactions and better sulfurability) for C (0001), A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" planes. In addition, EXAFS results suggest a predominantly basal orientation of the sulfide phase on the C (0001) plane while a random orientation is highlighted on the other faces. The surface structural analogies between α and γAl2O3 polymorphs allows us to transpose these results to the industrial support (γ-Al2O3) and hence, to conclude that a proper control of the industrial support morphology constitutes a way to tune the genesis of the sulfide phase and improve the performances of hydrotreating catalysts
Guillaume, Denis. "Modification et caractérisation des sites responsables du craquage acide sur des supports à base d'alumine." Paris 6, 1997. http://www.theses.fr/1997PA066368.
Ma, Jiwei. "Développement de catalyseurs cathodiques nanométriques sélectifs à l'environnement organique pour leur utilisation dans une pile microfluidique." Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2274/document.
Fuel cells without polymeric membrane such as the microfluidic fuel cells (MFFC) possess very interesting perspectives for low-power energy applications. The study aimed at pursuing the development of nanometric cathodic catalysts and to study their activity, stability and tolerance in a microfluidic system. In the present thesis, the activity, stability and tolerance of Pt-based nanoparticle electrocatalysts were investigated. The effect of the support materials and the influence of surface modification by a second element including 3d transition metal (titanium) and chalcogenide (selenium) were studied. The separation and reduction of the complexity of the interaction between nanoparticles-support and nanoparticles modification by a second element enables to achieve a clear relationship of the structure-activity-stability-tolerance of the supported fuel-cell electrocatalysts. The present experimental results from the effects of the support materials and of the modification of Pt by a second element led to improve activity, stability and tolerance. The developed approach and acquired knowledge about surface property correlation can be further generalized and used in the design of advanced selective electrocatalysts. Furthermore, the synthesized electrocatalysts were used as cathode in an organic microfluidic fuel cell
Humbert, Olivier. "Synthèse, caractérisations et propriétés de surface de nanopoudres d'oxydes à vocation catalytique." Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL086N.
We studied the influence of high energy bail milling crushing on Iwo types of oxides with catalytic properties. First of ail, two titanium dioxide powders (TiO2 PG and TiO2 GG) were characterized according to the time of milling. During milling, TiO2 anatase is transformed into rutile via a phase hot pressure/hot temperature called TiO2 Il. With TiO2 PG, we tried to correlate the decrease of the photocatalytic activity and the evolution of the properties of surface with the time of milling. The second family of oxides is composed of zirconia and ceria as weil as two solid solutions formed starting from these two powders. We compared the properties of surface of the powders synthesized according to three ways (an annealing and 2 milling) for the solid solutions and the effect of milling on the properties of surface of the starting powders. We could note notable and interesting differences between the powders obtained by milling and the powders obtained by thermal way
Dontsova, Dariya. "Titania based photocatalytically active layer-by-layer coatings on model surfaces and textile materials." Strasbourg, 2011. http://www.theses.fr/2011STRA6203.
The photocatalytic properties of commercially available and synthesized catalysts were studied for on-stream decomposition of a model odorous compound hydrogen sulphide (H2S) under UV-A and visible light irradiation. A simplified qualitative model for visualization of the catalyst deactivation is proposed. Further, catalysts were incorporated into multilayer films using different polyelectrolytes. Such films were characterized by ellipsometry, AFM, UV-visible spectroscopy and SEM on model surfaces. These films are homogeneous and transparent, and their porosity allow for almost free mass transport of the volatile compounds within the film. In order to test the photocatalytic activity of LbL films containing catalysts, such films were assembled on tubular glass reactors (with the diameter of 2. 7 cm and the length of 40 cm) and subjected to H2S flow under UV-A irradiation. The activity of films was found to be proportional to the number of film constituent layers of catalyst and dependent on the chemical nature of the film constituent polyelectrolyte. After the film structure was optimized with respect to catalytic component and polyelectrolyte component, the most efficient films were deposited on cotton textiles, and their photocatalytic activity was measured for on-stream decomposition of H2S under visible light irradiation. Further, the potential applications of such LbL-coated textiles for the removal of other common indoor pollutants were exemplified by decomposition of acetaldehyde, methyl ethyl ketone and ammonia gas under visible light irradiation
Goubert, Guillaume. "Étude de la (stéréo)sélectivité et d'interactions non covalentes à l’échelle de la molécule unique sur le Pt(111)." Doctoral thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/26180.
Le travail décrit au sein de cette thèse a pour objectif l’exploration des phénomènes liés au transfert de chiralité à des sites uniques sur une surface catalytique. Plus précisemment, le but est d’effectuer des études dynamiques de la stéréochimie sur des molécules uniques. Au cours de ce travail, plusieurs problématiques ont été explorées : 1. La question du transfert de chiralité sur une surface de catalyseur, le Pt(111). En particulier, le cas du transfert d’information chirale d’un modificateur chiral vers un substrat prochiral est étudié, les deux molécules étant liées de façon non-covalente. 2. L’étude et la définition de sites catalytiques uniques sur un catalyseur métallique, le Pt(111). 3. Le comportement dynamique de réactifs à des sites catalytiques uniques. Pour réaliser cette étude, on a utilisé le microscope à effet tunnel (STM), sur une surface de Pt(111) sous ultra haut vide (UHV), pour obtenir des images possédant une résolution moléculaire et sousmoléculaire des réactifs. Des images précises des assemblages entre modificateurs et réactifs peuvent ainsi être obtenues et les assemblages peuvent être classés en familles distinctes. L’acquisition de séries d’images dans le temps permet également d’obtenir une information dynamique sur la formation et la transformation des assemblages. Des expériences de spectroscopie vibrationnelle ont également été réalisées. Ces résultats expérimentaux en science des surfaces sont complétés par des calculs théoriques en théorie fonctionnelle de la densité (DFT) effectués par nos collaborateurs du groupe Hammer de l’Université d’Aarhus au Danemark. La synthèse de molécules et les tests en solution ont été effectués par les membres du groupe Boukouvalas du département de chimie de l’Université Laval. Cette méthode expérimentale permet l’étude de sites catalytiques uniques. La problématique de l’analyse des sites actifs sur un catalyseur est au coeur de la recherche en catalyse hétérogène moderne. Notre méthode est une des voies de recherche, complémentaire des études in situ et operando sur les catalyseurs en conditions réelles. En effet, le STM permet de caractériser des molécules uniques et de séparer espèces actives et spectatrices. Il ne fournit cependant pas d’information chimique directe. En effet, le courant tunnel ne donne pas d’information sur la source des électrons ou des atomes à travers lesquels les électrons ont pu passer. C’est pour cette raison que les calculs théoriques et les mesures de spectroscopie vibrationnelle sont importantes pour la compréhension des phénomènes de surface. En premier lieu, on a suivi dans le temps la déshydrogénation de l’ethylnaphtalène (chapitre 2) puis le bris d’une liaison C−N dans le pantoyl-naphtyléthylamine (PNEA) pour former une aminolactone chirale, décrite au chapitre 3. Cette dernière réaction n’était auparavant pas connue dans la litérature et l’effet de cette aminolactone sur le transfert de chiralité n’avait donc pas été envisagé. La dernière réaction étudiée est l’hydrogénation partielle du 2,2,2-trifluoroacétophénone (TFAP) au chapitre 5. Ce dernier cas a permis d’isoler un intermédiaire dans l’hydrogénation du TFAP, le produit final de l’hydrogénation, l’alcool, n’a pas été observé. La détermination de la structure chimique de cet intermédiaire a été possible en observant un changement dans la géométrie des assemblages bimoléculaires formés en fonction de la température, avec le support de calculs théoriques. Ce dernier cas montre que la géométrie des assemblages intermoléculaires est un marqueur utile de l’état chimique des espèces en surface. Il en résulte qu’une grande partie des résultats de cette thèse concerne l’identification et la caractérisation des liaisons non covalentes qui mènent aux assemblages intermoléculaires, en particulier les liaisons hydrogène faibles qui peuvent se former entre un carbonyle et les hydrogènes d’un groupement aryle ou alkyle dans le chapitre 2. La capacité de ces interactions à créer des assemblages intermoléculaire et à contrôler leur géométrie même en présence d’interactions fortes entre les molécules organiques et la surface métallique a également été étudiée. Dans le cas d’adsorbat chiraux, l’étude des assemblages intermoléculaires permet de comprendre les mécanismes de transfert de chiralité. En effet, dans le cas d’une réaction asymétrique sur une surface métallique les réactifs sont immobilisés dans une géométrie particulière par un modificateur chiral. Il est donc possible de découper la réaction à un site asymétrique comme suit : 1. Adsorption des réactifs 2. Rencontre du réactif avec le modificateur et formation d’assemblages énantiosélectifs. 3. Réaction au sites asymétrique et formation d’un énantiomère du produit de façon préférentielle. Il en découle que l’étude des assemblages énantiosélectifs permet de mieux comprendre le transfert de chiralité. C’est ce qui a été réalisé au chapitre 3 pour l’étude des assemblages entre l’aminolactone chirale formée in-situ avec le TFAP et le cétopantolactone (KPL). On a ainsi montré qu’en présence de KPL, des assemblages multimoléculaires sont formés. Ce mode d’interaction n’avait jamais été observé ni postulé dans la littérature pour des systèmes catalytiques asymétriques. Dans le chapitre 4, les assemblages entre le méthylebenzoyl formate (MBF) et le (R)-1-(1-naphtyléthyleamine) (R)-NEA) ont été étudiés. On a examiné s’il était possible généraliser les résultats obtenus précédemment sur les assemblages entre le (R)-NEA et le TFAP [1] puis le méthyle trifluoropyruvate (MTFP) [2], pour expliquer le rôle des liaisons hydrogène, de la répulsion stérique et des sites d’adsorption sur la géométrie des assemblages. La dernière partie de mes travaux concerne l’étude de la diffusion des réactifs sur la surface, en particulier le (R)-NEA) et le TFAP aux chapitres 6 et 7. Nous avons montré que la diffusion des deux conformères du (R)-NEA) est très différentes, ce qui montre que c’est un marqueur précis de la structure chimique. La diffusion peut être considérée comme une autre façon d’attaquer le problème du transfert de chiralité. En effet la liberté de diffusion des réactifs contrôle l’accès aux différents sites catalytiques et le passage de l’un à l’autre comme on le montre au chapitre 7.
Garcia, de Castro Insua Ricardo Antonio. "Catalyseurs d’hydrotraitement modèles à base du Mo et supportés sur α-Al2O3 : étude sur l’incorporation du cobalt, phosphore et triéthylène glycol par une approche de science de surfaces". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS145.
The genesis of the active phase in hydrotreating catalysts is deeply influenced by the nature of the support. However, a fine description of active phase-support interactions at the molecular level is still missing since the traditional support γ-Al2O3 exhibits ill-defined sorption sites. A surface-science approach in aqueous phase circumvented this limitation by using α-Al2O3 single crystals with four different orientations: C(0001), A(112 ̅0), M(101 ̅0), and R(11 ̅02) as surrogates to study the genesis of MoS2 exerting control over surface sites. Such approach revealed that properties of MoS2 were dictated by Mo-support interactions which are, in turn, determined by the nature of surface -OH. The present work aims to take a step further in closing the gap between model and industrial catalysts by incorporating cobalt, phosphorus and TEG in model catalyst formulation. Surface-sensitive techniques are used to expose such dependencies. It is shown that phosphorus interacts differently depending on support orientation, leading to a surface-dependent sulfidation. Conversely, it is shown that cobalt promotion of MoS2 is exclusively dependent on Mo sulfidation. At last, it is shown how omitting calcination and TEG incorporation reduces metal-support interactions leading to higher sulfidation. The catalytic activity of promoted catalysts is studied through a thiophene hydrodesulfurization reaction revealing that A(112 ̅0)-based catalysts display the highest activity. In that sense, intermediate metal-support interactions are key to achieve higher catalytic performance. These results could lead to a new generation of hydrotreating catalysts through control of support morphology
Bentahar, Fatima Zohra. "Etude de la réactivité de composés alkyls, alcoolates et carboxylates d'étain tributyle avec les surfaces de platine et de palladium supportés sur silice, alumine ou charbon : application des catalyseurs bimétalliques obtenus à la déshydrogénation de l'isobutane en isobutène." Lyon 1, 1997. http://www.theses.fr/1997LYO10078.
Doghri, Hanène Kaouther. "Conception des catalyseurs hétérogènes bio-inspirés à base de métaux divalents greffés dans des silices mésoporeuses pour l'activation de CO2." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEN032.
Bio-inspired diethylenetriamine zinc(II) complexes were anchored into the nanopores of hexagonal mesoporous MCM41-like silicas. A step-by-step approach called “Molecular Stencil Patterning” was adopted to perform an in situ synthesis in order to mimic the zinc finger of the carbonic anhydrase. In the presence of a surface-masking pattern of TMA+ ions, some silanol groups were capped using grafted trimethylsilyl functions. Transition metal complexes have also been anchored in analogy to the metallic site of carbonic anhydrase with a molecular vicinity control comparable to that of materials containing zinc complexes. The interaction of adsorbed CO2 with the active sites of these materials has also been studied. The materials were characterized with a panel of techniques including XRD, elemental analysis, N2-adsorption-desorption, FT-IR, 29Si NMR, XPS and EPR that confirm the integrity of the porous structure and the complexes formation
Leroux, Denis. "Polystyrène sulfoné supporté sur silice poreuse : greffage et activité en catalyse acide." Lyon 1, 1994. http://www.theses.fr/1994LYO10290.
Chatelier, Corentin. "On the surface structures and catalytic properties of Al-based intermetallics." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0230.
Replacing noble metal (Pd, Pt, Au) catalysts with inexpensive, environmentally harmless, active, selective, and stable substitutes is a big challenge for the chemical industry. Several aluminium-based complex intermetallic compounds have shown promises for alkynes and alkenes hydrogenation reactions, which are of interest in the chemical industry. It is the case for Al5Co2, Al13Co4 and Al13Fe4 quasicrystalline approximants. The study of their catalytic properties demands different approaches, both theoretical and experimental, in order to determine first their surface structures under ultra-high vacuum or reaction conditions, then their catalytic properties. The combination of surface science experiments (scanning tunneling microscopy, surface X-ray diffraction) and theoretical chemistry calculations (surface energies, adsorption energies and reaction pathways) allows for a better understanding of the key parameters behind the promising catalytic properties of these materials
Hamraoui, Karim. "Étude théorique de la nature et de la réductibilité des entités d'oxyde de molybdène supportées sur l'oxyde de titane." Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-285.pdf.
Théodet, Manuel. "Nouvelle génération de précurseurs "bulk" de catalyseur d'hydrodésulfuration synthétisés en milieu fluides supercritique." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00559113.
Prin, Marie. "Effet stabilisant de cations sur l'évolution texturale d'un oxyde de cérium : Étude expérimentale et modélisation." Grenoble INPG, 1991. http://tel.archives-ouvertes.fr/tel-00844646.
Loffreda, David. "Modélisation théorique de l'adsorption et de la réactivité de la molécule NO sur les surfaces de catalyseurs à base de palladium, de rhodium et d'alliages palladium-manganèse." Lyon 1, 1999. http://www.theses.fr/1999LYO10295.
Souquet-Grumey, Julien. "Fonctionnalisation de nouveaux composites carbone-carbone et leur valorisation en catalyse hétérogène." Poitiers, 2010. http://www.theses.fr/2010POIT2316.
Tran, Quang Thuan. "Amination, phosphorylation spontanée ou électro assistée de surface de carbone vitreux pour l'élaboration de nouvelles électrode ligands." Rennes 1, 2011. http://www.theses.fr/2011REN1S122.
The objective of this thesis is to graft ligands on a support for facilitating the recovering and recycling of the catalyst. Furthermore, by using the electrode as a support, the redox state of the catalyst can be easily modulated by controlling the applied potential. We can therefore utilize one catalyst system for many reactions. The phosphine ligands, highly efficient in catalysis, were grafted on the surface of glassy carbon electrode using free radical electro-grafting methods. These methods are convenient procedure allowing the formation of robust linkage between the surface and the phosphine ligand moiety. These radicals are electrochemically generated by electro-oxidation amine or by electro-reduction of aryl diazonium salt generated from the diazotization in-situ of the aromatic amine. In this work, a major drawback which is the sensitivity of the phosphine ligand toward the chemical and electrochemical oxidation, was solved by the introduction of a borane moiety as a phosphines protecting group. We synthesized different aminophosphine-borane ligands and their corresponding organometallic complexes (Mo, Mn, Ru) both in solution and in solid-state, when grafted onto surfaces. These complexes were characterized by different techniques including NMR (¹H, ¹³C, ³¹P), X-ray diffraction, X-ray photoelectron spectroscopy and cyclic voltammetry. A promising preliminary result was obtained in the electro-catalysis of the oxidation reaction of an alcohol
Herbin, Morgane. "Etude de l’influence de différents modes de synthèse sur la nature de la phase active de catalyseurs à base de molybdène : Caractérisation par couplage de spectroscopies XPS/LEIS/ToF-SIMS." Electronic Thesis or Diss., Lille 1, 2014. http://www.theses.fr/2014LIL10069.
The coupling of surface analysis techniques (XPS, LEIS et ToF-SIMS) allowed to characterize the nature of the active phase on Mo-based catalysts according to different modes of synthesis. To imitate chemical means by impregnation mode, model catalysts we prepared by spin-coating. In addition, a new physical path, by magnetron sputtering, has been explored for the synthesis of catalysts. Correlations between spectroscopic data XPS and LEIS on model systems determine the recovery rate and the structure of the active phase : Mo low content monomeric and high content polymeric entities. Finally, the catalytic performances of the different catalytic systems for the controlled oxidation of methanol are discussed under spectroscopic characterizations. This work has been performed within INTERREG IV CATARR network (Materia Nova, Mons University and Lille1 University)
Bordet, Alexis. "Une nouvelle génération de nano-catalyseurs à base de carbure de fer pour le stockage chimique de l'énergie." Thesis, Toulouse, INSA, 2016. http://www.theses.fr/2016ISAT0017/document.
After several decades of oblivious fossil resources consumption, humanity is now facing major issues regarding global warming and energy production and storage. In the double context of intermittent renewable energy storage and CO2 recovery, the power-to-gas approach, and especially the Sabatier reaction (catalytic hydrogenation of carbon dioxide to methane + water) is of special interest. The main goal of this thesis is to perform the Sabatier reaction using magnetically activated nano-catalysts. The use of magnetic nanoparticles to convert electromagnetic energy into heat is indeed an approach of growing interest in catalysis, even if the field of biomedicine obviously concentrate most of the applications (magnetic hyperthermia, drug delivery, etc.). In this respect, the interest of the synthesized nanoparticles for biomedical applications is studied and discussed. We describe herein a pathway to iron carbide nanoparticles allowing a fine tuning of their carbon content and magnetic properties. We show that the carbon content and the crystallinity of the synthesized nanoparticles greatly impact their magnetic heating efficiency. The Fe2.2C crystallographic phase especially appears to be the key to highly enhanced specific absorption rates (SARs). We took advantage of these exceptional heating properties to investigate the Sabatier reaction in a continuous flow reactor, the catalyst being activated through magnetic induction. The SAR of synthesized iron carbide nanoparticles appeared to be sufficient to reach the temperature required for the activation of the Sabatier reaction (typically > 250°C), and promising results were obtained in a continuous flow reactor. We were thus able to demonstrate that the concept of magnetically induced catalysis can be successfully applied to the CO2 methanation reaction and represents an approach of strategic interest in the double context of intermittent energy storage and CO2 valorization
Gómez, Badillo Jennifer Sarelly. "Développement de méthodes RMN-(DNP) à hauts champs pour la détection des noyaux quadripolaires sur des surfaces." Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR041.
Surfaces are fundamental in the performance of modern materials. Surface properties play an important role in many fields as diverse as nanoscience, electrochemistry, electronics, energy conversion and storage as well as medicine. Therefore, fundamental understanding of surface processes and the characterization of their chemical properties are of central importance in developing new materials to meet nowadays challenges. However, the structural characterization of surface species at the atomic level is frequently challenging because they often lack long-range positional order and their fractions, among all sites, typically are quite low. Solid‐state NMR spectroscopy provides unique information on the local atomic-level structure. Nevertheless, the lack of sensitivity of NMR poses a major limitation to surface characterization especially when the investigated materials contain quadrupolar nuclei.Half-integer quadrupolar nuclei, such as 11B, 17O and 27Al, represent about two thirds of stable NMR-active nuclei and are present in several organic, inorganic and biological solids. However, the NMR observation of these nuclei in solid surfaces remains often more challenging because of the larger size of the density matrix for quadrupolar nuclei as well as the large quadrupolar interaction, which broadens their resonances and complicates the spin dynamics. The NMR signal of the surface can be selectively detected by a coherent transfer of the 1H polarization to the surface nuclei. In the case of half-integer quadrupolar nuclei, the cross-polarization under magic-angle spinning (CPMAS) technique lacks robustness and it is preferable to use methods for which no spin-lock is applied to the quadrupolar nucleus. Two types of sequences, without any spin-lock, can be used in this case: through-space refocused INEPT (D-RINEPT) and PRESTO.In this work, we introduced new robust symmetry-based heteronuclear dipolar recouplings built from composite inversion pulses, which can be combined with D-RINEPT and PRESTO schemes to transfer the polarization of protons to quadrupolar nuclei at MAS frequencies higher than 20 kHz. These transfers can be combined with DNP to enhance the NMR signals of quadrupolar isotopes, notably near the surface of the materials. Furthermore, they can be used to acquire hetereronuclear correlation spectra of protons and quadrupolar nuclei at fast MAS (62.5 kHz).For the observation of homonuclear proximities between quadrupolar nuclei, we have compared the performances of symmetry-based homonuclear dipolar recoupling schemes for nuclei with spin value I = 3/2, such as 11B, and 5/2, such as 27Al. For both isotopes, the double-quantum (DQ)-single-quantum (SQ) sequences are recommended, which yields good efficiency for both the cross- and auto-correlation peaks. For 11B isotope, the chemical shift differences are small or moderate, and therefore, bracketed recoupling schemes are recommended. For 27Al nuclei, the chemical shift differences are larger and un-bracketed recoupling schemes are recommended.We also investigated the surface of boron nitride and oxide supported on dendritic fibrous nanosilica, which are catalyst for the oxidative dehydrogenation of propane. Through a combination of 1D and 2D multinuclear (1H, 29Si and 11B) solid-state NMR experiments, it was demonstrated that BN phase undergoes a transformation to B2O3 (oxidation) during the reaction, which led to a larger fraction of hydrogen-bonded BOH groups at the surface of oxidized DFNS/BN with respect to as-prepared DFNS/B2O3. This structural difference could explain the higher selectivity towards propene of oxidized DFNS/BN
Molina, Jotel Laura. "Amélioration, optimisation et développement des procédés d'élaboration de matériaux catalytiques." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0134.
L’objectif de la thèse est de fabriquer des structures catalytiques washcoatées de taille centimétrique pour différentes réactions catalytiques comme le vaporeformage et le pré-reformage, le SNG (Substitute Natural Gas) et le MTP (Methanol to Propylene). L’étude de l’utilisation de ces structures alternatives aux catalyseurs extrudés conventionnels utilisés dans l’industrie est la conséquence des contraintes opératoires (gradients de pression et de température) et leur influence sur les coûts opératoires (endommagement des matériaux, désactivation des catalyseurs, perte de charge dans les réacteurs, etc.). Le dépôt des catalyseurs sur les architectures céramiques et métalliques a été possible grâce à l’étude minutieuse du comportement des solides catalytiques en suspension dans un milieu liquide. Le contrôle de paramètres comme la chimie de surface et la rhéologie a été nécessaire pour acquérir une maîtrise nécessaire afin d’obtenir des pièces catalytiques avec un dépôt homogène, stable mécaniquement et non fissuré
Yuan, Zheng. "Croissance de Nanoparticules de Pd sur surfaces de HOPG préstructurées." Thesis, Mulhouse, 2013. http://www.theses.fr/2013MULH4817/document.
Nanoparticles exhibit size-related properties that different from those observed in bulk materials. Nanoparticle research has attracted intense interest due to its great potential applications. It has been shown that some metallic nanoparticles are catalytically active and effective, such as-Palladium.The aim of this thesis is to study the formation of Pd nanoparticles deposited on pre-structured HOPG (Highly Ordered Pyrolytic Graphite) surfaces in order to optimize their size, density and surface stability. Three major steps were taken in our studies: preparation of substrates, deposition of Pd and characterization of samples by scanning tunneling microscopy (STM). Substrats preparations itself contains two steps : the creation of defects by Aun+ clusters implantation or by bombardment of Co2 ions, followed by thermal oxidation. These steps give the formation of hales with controlled depth and diameter, which serve as anchoring sites for Pd nanoparticles.The STM measurements have allowed us to establish the relationships between the quantity of deposited Pd and the size of Pd nanoparticles formed on the HOPG surface. Two growth modes were clearly observed which are related to the defect sizes created on the HOPG surface. Nanoparticles are present either in the form of pearl necklace or in the form of isolated particles. These samples were then characterized by catalytic measurements in organic synthesis (Heck) and gas catalysis (CO oxidation)
Huang, Lin. "Chimie organométalllique de surface, étude de la chimisorption et de la thermodécomposition de clusters bimétalliques du groupe VIII supportés sur magnésie : propriétés catalytiques en synthèse Fischer-Tropsch." Lyon 1, 1987. http://www.theses.fr/1987LYO10029.
Colin-Gouillou, Marie. "Etude théorique de l'échange isotopique H/D et 16-O/18-O sur la surface (001) de MgO." Poitiers, 1999. http://www.theses.fr/1999POIT2294.
Xia, Yuzhen. "Carbone fonctionnalisé pour une meilleure performance des piles à combustible." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0116/document.
In the development of the performances of PEM fuel cell, sulfonated Pt/Vulcan catalysts were prepared by grafting with either polystyrene sulfonate (PSSA) or with 4-phenysulfonic acid (PSA). The influences of the graft ratio, the amount of Nafion and the gas diffusion layer, on the electrochemical performances were studied in a half-cell and membrane electrode assembage (MEA). Larger electrochemical surface area of the catalyst was obtained in the presence of microporous layer on the carbon paper, as well as higher ORR current and lower charge transfer resistance. PSSA was grafted onto Pt/Vulcan catalysts by in-situ radical polymerization with 5, 10 and 20 wt.% sodium styrene sulfonate. It was presented in the half-cell tests and fuel cell tests that the catalysts grafted with 5 and 10 wt.% sulfonated groups performed improved properties. Pt/Vulcan catalysts were also grafted with 5.8, 11.6 18.0 and 23.3 wt.% PSA. Compared with non-functionalized catalysts, significant developments were achieved because of the sulfonation. The MEA with 18.0 wt.% PSA was studied in accelerated durability tests and showed excellent durability after 3000 cycles. For half-cells and MEAs with catalysts grafted with 5wt.% PSSA or PSA groups, low Nafion addition resulted in to lower performances. However, the MEAs with 10 and 20 wt.% PSSA exhibited an enhanced performance than the counterparts with 0.50 mg•cm-2 Nafion
Muller, Sébastien. "Caractérisation de catalyseurs deNOx et deN2O par modélisation LSER (Linear Solvation Energy Relationship) : étude structure-propriétés." Thesis, Metz, 2008. http://www.theses.fr/2008METZ048S.
This study presents the characterisation of deNOx and deN2O catalysts in terms of structure-properties relationship in order to understand the different interactions involved between catalysts and gaseous species present in the system and to contribute to the formulation of these materials. The LSER modelisation (Linear Solvation Energy Relationship) allows us to prove the interactions involve during the adsorption process of compounds at the surface. The evolution of the catalyst’s surface after different treatments is following by the LSER approach. The comparison of the affinity proves the differences observed in the LSER equations: especially the polarity, basicity and acidity terms, implicated in aromatics, alcohol and water adsorption. This method shows differences between different steps in the processes of NOx and N2O elimination (as the strong adsorption of reducers on the catalyst for the coal-deNOx, whereas the same effect involves weaker performances in the case of the deN2O. The LSER method which consists in a thermodynamic approach, is a new useful technique for the understanding of the phenomenon involved in the deNOx and deN2O catalysis processes. It also demonstrates that the adsorption processes are not so important in the catalysts performances
Xu, Minrui. "Synthèse et caractérisation de catalyseurs acido-basiques par greffage covalent sur supports carbonés. Application dans le domaine de la valorisation de molécules bio-sourcées." Thesis, Poitiers, 2019. http://www.theses.fr/2019POIT2292/document.
Homogeneous catalyst applications are usually limited in industrial chemical processes because massive wastes are produced and catalyst separation with raw materials and products is inconvenient during industrial production processes. As a result, the heterogenization of homogeneous catalysts onto solid supports was often investigated and proven to be more promising for industrial applications. Nevertheless, not only the tedious catalyst synthesis but also the low catalyst loadings and the resulting low efficiencies contribute to the high cost of supported catalysts. To remedy the deficiency of supported catalysis, scientists have worked on direct functionalization of solid support via covalent bond building. Among the approaches of functionalization being investigated, the chemistry of diazonium developed by Griess is becoming more and more popular and attractive since this promising method enables to graft different organic moieties onto various solid supports. During past few years, the functionalization of carbonaceous materials was widely developed because carbon is an inexpensive and extensively available material. In this study, the spontaneous functionalization of carbonaceous materials (Darco KB-G; Norit SX2 and Vulcan XC72) can lead to basic or acid solids by respectively grafting different aminophenyl groups (phenylimidazole; N,N,dimethylaniline, aniline, phenylmorpholine) for basic solids and phenyl sulfonic group for acid solids, via diazonium chemistry.The functionalized solids were characterized by different technics (elemental analysis, N2 adsorption-desorption, TGA, SEM, FT-IR, XPS and Raman spectroscopy) and used in different model reactions to upgrade bio-resourced platform molecules, especially furfural. For instance, the usefulness and effectiveness of these new basic solids are illustrated with the Knœvenagel condensation between furfural and malononitrile under mild conditions leading to 2-furanylmethylene malononitrile and water. The basic solid Darco-0.5PDA exhibited high activity to the Knœvenagel condensation of furfural and malononitrile under mild experimental conditions (40 °C, Patm). The catalytic performance of functionalized acid solids was assessed in the acetalization reaction of dodecyl aldehyde with ethylene glycol at 60 °C under atmospheric pressure in both conventional and solvent-free PIC (Pickering Interfacial Catalysis) conditions. The experiments evidenced that the synthesized amphiphilic acid solid stabilized dodecyl aldehyde/ethylene glycol Pickering emulsions and demonstrated both good stability and activity in a solvent-free biphasic acetalization
Nandi, Shreya. "Investigation of perovskite-based three-way catalysts using surface analysis techniques and in situ/operando spectroscopy." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R072.
The catalytic after-treatment of exhaust gases from gasoline engines requires simultaneous abatement of CO, NO and hydrocarbons and is commonly called three-way catalysis (TWC). Perovskites based materials like LaFeO3, regarded as intelligent supports, are being considered as potential candidates as alternative TWC in context of reducing noble metal content. Such bulk catalysts often demonstrate variable surface compositions in comparison to the bulk. Since surface determines the catalytic performance in heterogeneous catalysis, deeper understanding of the surface characteristics especially under relevant reaction conditions becomes imperative. To this end, LaFeO3 based model catalysts relevant to conventional catalysts have been investigated by combination of advanced surface analysis techniques like XPS, LEIS and ToF-SIMS to study the existing surface variations. In addition, catalysts behavior was studied under CO atmosphere by NAP-XPS and GI-XANES. This methodology allowed to reveal that inducing a La-deficiency in the structure helps to improve the catalytic performance due to an interfacial effect. In addition, the different catalytic operating modes of Cu or Mn substituted perovskite powders were determined by in situ/operando Raman spectroscopy
Nandi, Shreya. "Investigation of perovskite-based three-way catalysts using surface analysis techniques and in situ/operando spectroscopy." Electronic Thesis or Diss., Université de Lille (2018-2021), 2019. http://www.theses.fr/2019LILUR072.
The catalytic after-treatment of exhaust gases from gasoline engines requires simultaneous abatement of CO, NO and hydrocarbons and is commonly called three-way catalysis (TWC). Perovskites based materials like LaFeO3, regarded as intelligent supports, are being considered as potential candidates as alternative TWC in context of reducing noble metal content. Such bulk catalysts often demonstrate variable surface compositions in comparison to the bulk. Since surface determines the catalytic performance in heterogeneous catalysis, deeper understanding of the surface characteristics especially under relevant reaction conditions becomes imperative. To this end, LaFeO3 based model catalysts relevant to conventional catalysts have been investigated by combination of advanced surface analysis techniques like XPS, LEIS and ToF-SIMS to study the existing surface variations. In addition, catalysts behavior was studied under CO atmosphere by NAP-XPS and GI-XANES. This methodology allowed to reveal that inducing a La-deficiency in the structure helps to improve the catalytic performance due to an interfacial effect. In addition, the different catalytic operating modes of Cu or Mn substituted perovskite powders were determined by in situ/operando Raman spectroscopy
Devillard, Didier. "Interaction du thiophène avec les oxydes de nickel et de cobalt : face (100) de monocristaux et surfaces modèles de catalyseurs d'oxydes mixtes Ni-Mo et Co-Mo : étude par spectrométrie Auger et diffraction d'électrons de haute énergie sous incidence rasante." Dijon, 1990. http://www.theses.fr/1990DIJOS019.
Herbin, Morgane. "Etude de l’influence de différents modes de synthèse sur la nature de la phase active de catalyseurs à base de molybdène : Caractérisation par couplage de spectroscopies XPS/LEIS/ToF-SIMS." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10069/document.
The coupling of surface analysis techniques (XPS, LEIS et ToF-SIMS) allowed to characterize the nature of the active phase on Mo-based catalysts according to different modes of synthesis. To imitate chemical means by impregnation mode, model catalysts we prepared by spin-coating. In addition, a new physical path, by magnetron sputtering, has been explored for the synthesis of catalysts. Correlations between spectroscopic data XPS and LEIS on model systems determine the recovery rate and the structure of the active phase : Mo low content monomeric and high content polymeric entities. Finally, the catalytic performances of the different catalytic systems for the controlled oxidation of methanol are discussed under spectroscopic characterizations. This work has been performed within INTERREG IV CATARR network (Materia Nova, Mons University and Lille1 University)
Zhang, Kun. "Mesostructured porous materials : Pore and surface engineering towards bio-inspired synthesis of heterogeneous copper catalysts." Lyon, École normale supérieure (sciences), 2008. http://www.theses.fr/2008ENSL0470.
Advanced control of the surface structure and chemistry in confined space has been developed here in mesostructured porous silicas of MCM-41 type to design novel metal supported catalysts combining confinement, hydrophobicity and site specificity using the inspiring model of metalloproteins. First, it is demonstrated that the surface of such a type of materials usually seen as smooth has indeed an alveolar structure generated by the imprint of the ammonium surfactant head groups used here as directing agent. Increasing hydrothermal temperatures is shown first to enlarge the pore size by mere surface smoothing followed by a decrease explained by wall thickening. In addition, conditions were found to generate hybrid materials with hierarchical micro- and mesoporority. Finally, both rough and smooth surfaces were found amenable for multifonctionnalization using molecular stencil patterning technique and compared for isolation of bidentate aminoethyleaminopropyl tethers by trimethylsilyl grafted hydrophobic groups. Then copper (II) can easily be retained by complexation to these bidentate tethers inside the nanochannels of the material
El, Mansour Abdellah. "Chimie organométallique de surface sur métaux étude de la préparation de catalyseurs bimétalliques par réaction de Sn(Bu) avec le catalyseur Rh/SiO sous différents états d'oxydation." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375994230.
Calmettes, Stéphanie. "Conception d'un catalyseur par greffage d'un complexe de ruthénium en milieu confiné ; Application à l'oxydation sélective." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2008. http://tel.archives-ouvertes.fr/tel-00292814.
Mansour, Abdellah El. "Chimie organométallique de surface sur métaux : étude de la préparation de catalyseurs bimétalliques par réaction de Sn(Bu)4 avec le catalyseur Rh-SiO2 sous différents états d'oxydation." Lyon 1, 1986. http://www.theses.fr/1986LYO11713.
Martin, Dominique. "Mobilité de surface des espèces oxygénées et hydrogénées en catalyse métallique." Poitiers, 1994. http://www.theses.fr/1994POIT2313.
Zhang, Kun. "Mesostructured porous materials : Pore and surface engineering towards bio-inspired synthesis of heterogeneous copper catalysts." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2008. http://tel.archives-ouvertes.fr/tel-00310153.
Capdevielle-Salinier, Valérie. "Préparation de catalyseurs organométalliques de surface du zirconium : application à la transestérification." Lyon 1, 1996. http://www.theses.fr/1996LYO10111.