La synthèse de nitriles gras à partir de ressources renouvelables est un domaine qui attire depuis quelques temps les industries de la parfumerie, des polymères et des biocarburants pour avion. Ce travail de thèse s’est plus particulièrement intéressé à réduire de 100°C la température de travail pour les procédés en phase liquide et gaz, au moyen de catalyseurs plus efficaces. Le procédé en phase liquide a été étudié en terme de catalyse homogène et les formes actives à base de zinc ou indium ont été plus particulièrement détaillées ; des conditions ont été établies pour obtenir une réduction de 50°C de la température de travail. Le procédé en phase gaz a été étudié en terme de catalyse hétérogène, les catalyseurs obtenus ou synthétisés étant caractérisés par microcalorimétrie d’adsorption ; des corrélations entre la conversion de l’ester et l’acidité du lit catalytique ont été trouvées à 300°C, et des conditions expérimentales ont été développées pour obtenir une conversion totale à une température réduite de 100°C sur des catalyseurs choisis / The production of fatty nitriles from renewable sources has lately become attractive for the perfume, polymer and aviation biofuel industry. The present work investigated both liquidand gas-phase processes in the aim of developing catalysts working at 200°C, this is 100°C lower than the state-of-the-art. Homogeneous catalysis was described with zinc and indium based species for the liquid-phase process, succeeding in reducing by 50°C the operating temperature. Heterogeneous catalysts with acid-base features were characterized by adsorption calorimetry and tested in the gas-phase process, leading to correlations between acidity and ester conversion at 300°C, while conditions were found on selected catalysts in order for the process to perform the complete conversion of esters into nitriles at 200°C

Ces travaux de thèse portent sur la possibilité de combiner la catalyse hétérogène et la catalyse enzymatique dans une réaction en cascade de transformation de la cellulose en produits d’intérêt. Le prétraitement enzymatique (Celluclast, un cocktail de cellulases) a été choisi comme première étape de transformation de la cellulose en vue de la fragiliser; elle est réalisée dans une solution tampon d’acide acétique et d’acétate de sodium à pH 4,75, à 50°C. Cette étape produit principalement du glucose et modifie structurellement la cellulose résiduelle en diminuant seulement son degré de polymérisation (DP), fournissant de nouvelles extrémités réductrices sans toucher sa cristallinité. L’identification des verrous de la deuxième étape de catalyse hétérogène, réalisée en autoclave à une température supérieure ou égale à 190°C, a consisté à trouver un catalyseur hétérogène qui peut tolérer le milieu réactionnel enzymatique tamponné, qui peut avoir une activité catalytique favorisée sur les celluloses de DP inferieurs et qui peut valoriser le glucose obtenu dans des conditions identiques à la cellulose. Parmi les différentes familles de catalyseurs testés, le catalyseur métallique à base de Pt/charbon, s’est révélé plus efficace que les catalyseurs acides de Lewis et de Brønsted en raison de sa résistance au milieu tamponné et de sa capacité à convertir la cellulose et le glucose dans des conditions identiques malgré l’insensibilité de ce type de catalyseur de la diminution du DP de la cellulose prétraitée. Il a permis de convertir sélectivement la cellulose en propylène et éthylène glycols à 240°C dans une transformation cascade incluant une étape enzymatique suivie d’une étape catalytique hétérogène / This thesis deals with the possibility of combining heterogeneous catalysis and enzymatic catalysis in a cascade reaction for cellulose transformation into value-added products. The enzymatic pretreatment was chosen as the first cellulose transformation step to weaken the cellulose structure which is carried out in a buffer solution of acetic acid and sodium acetate at a pH 4.75, at 50°C. This step is selective, producing mainly glucose, and it has structurally modified the residual cellulose by only decreasing its degree of polymerization (DP) by providing new reducing ends without affecting its crystallinity. The challenges of the second step, heterogeneous catalysis, which is done in a closed autoclave at a temperature greater than or equal to 190°C, were then to find a heterogeneous catalyst that can tolerate the buffered enzyme reaction medium, that can have a favored activity on lower DP celluloses and that can valorize the obtained glucose and cellulose in identical conditions. Among the different families of catalysts tested, the metallic catalyst based on Pt/carbon was shown to be more efficient than the other Lewis and Brønsted acid catalysts due to its resistance to the buffer medium and its abilities to valorize glucose and cellulose in equivalent conditions despite the independence of this type of catalyst to the reduction of the DP of the pretreated cellulose. It allowed to selectively convert cellulose into propylene and ethylene glycols at 240°C in a cascade reaction including an enzymatic catalytic step and a heterogeneously catalyzed one

L'EU-1 et la MCM-22 sont deux zéolithes à taille de pores intermédiaire, utilisées respectivement pour l'isomérisation de la coupe C8 aromatique et l'alkylation du benzène par des oléfines légères. Leurs propriétés catalytiques originales sont dues à une contribution très importante des sites acides localisés sur leur surface externe. Au cours de ce travail, différentes approches ont été envisagées pour augmenter la quantité ou la proportion de ces sites aux dépends des sites internes. Tout d'abord, une série de zéolithes H-EU-1 partiellement échangées par du sodium a été préparée et caractérisée par voie physicochimique et par des réactions modèles. Comme attendu, l'échange s'accompagne d'une diminution de la concentration en sites acides de Brönsted. Toutefois, une augmentation importante de la quantité de sites acides très forts a été observée pour des taux d'échange de 26 à 35 % et corrélée à l'augmentation de l'activité en craquage du méthylcyclohexane. Par ailleurs, les conversions du m-xylène et du 1,3,5-triméthylbenzène diminuent rapidement pour de faibles taux d'échange, ce qui pourrait s'expliquer par un échange préférentiel des sites acides externes, également mis en évidence dans le cas de zéolithes MCM-22. Enfin, une nouvelle zéolithe de la famille MWW a été synthétisée et caractérisée. Cette zéolithe possède une acidité totale similaire à celle de la MCM-22, mais une proportion de sites acides externes beaucoup plus importante, conduisant à une activité beaucoup plus grande en transformation du m-xylène et du 1,3,5-triméthylbenzène. Cette nouvelle zéolithe pourrait donc constituer une alternative intéressante à la zéolithe MCM-22 en alkylation du benzène. / EU-1 and MCM-22 are two 10-ring zeolites used in petrochemical applications such as C8-aromatic cut isomerization and benzene alkylation with short olefins. In all these processes, the original catalytic behaviors of both zeolites are characterized by an important contribution of the acid sites located over the external surface of their crystals. In this work, different methods were investigated in order to increase the amount or the proportion of these acid sites at the expense of those located inside the pores. Firstly, a series of partially Na-exchanged H-EU-1 was prepared and fully characterized through physicochemical techniques and model reactions. As expected, the exchange led to a gradual decrease in the total Brönsted site concentration. Nevertheless, an increase of the concentration in very strong acid sites was obtained for exchange ratio between 26 and 35%, leading to a significant increase of the activity in methylcyclohexane transformation. On the other hand, m-xylene and 1,3,5-trimethylbenzene (135-TMB) conversions decreased rapidly at low exchange ratio, which was attributed to a preferential exchange of the external acid sites. This latter phenomenon was also observed over Na-exchanged H-MCM-22 zeolites. Secondly, a new zeolite belonging to the MWW family was synthesized and characterized. This zeolite was shown to possess the same acid site concentration than MCM-22 zeolite but with a much higher proportion of external sites. In consequence, it exhibited a very high catalytic activity in both m-xylene and 135-TMB transformations. This material could therefore be considered as an alternative to MCM-22 in the benzene alkylation process. / EU-1 e MCM-22 são dois zeólitos de poros intermédios utilizados, respetivamente, na isomerização do corte C8 aromático e na alquilação do benzeno com olefinas leves. As suas propriedades catalíticas originais devem-se a uma importante contribuição dos centros ácidos localizados nas superfície externa. Nesta tese, diferentes abordagens foram investigadas com o objetivo de aumentar a quantidade ou a proporção destes centros ácidos em detrimento dos centros internos. Primeiramente, uma série de zeólitos H-EU-1 parcialmente permutados com sódio foi preparada e caracterizada por via físico-química e por reações modelo. Como esperado, a permuta é acompanhada por uma diminuição da concentração em centros ácidos de Brönsted. Contudo, um importante aumento da quantidade de centros ácidos muito fortes foi obtido para taxas de permuta entre 26 e 35% e correlacionado com um aumento da atividade no cracking do metilciclohexano. Por outro lado, as conversões do m-xileno e do 1,3,5-trimetilbenzeno diminuem rapidamente para baixas taxas de permuta, o que pode ser explicado por uma permuta preferencial dos centros ácidos externos. Este último fenómeno foi igualmente observado no caso do zeólito H-MCM-22 permutado com sódio. Por fim, um novo zeólito pertencente à família MWW foi sintetizado e caracterizado. Este zeólito demonstrou possuir uma acidez total semelhante à do zeólito MCM-22, porém com uma muito maior proporção de centros ácidos externos, conduzindo a uma bastante superior atividade nas transformações do m-xileno e do 1,3,5-trimetilbenzeno. Este novozeólito poderá, portanto, representar uma alternativa interessante ao zeólito MCM-22 na alquilação do benzeno.

Materiais altamente especializados (polifuncionais) continuam a ser candidatos chave para avanços na área tecnológica e biológica. Buscando aplicação em campos diversos, foram sintetizadas estruturas dendríticas (dendrímeros e polímeros hiperramificados) do tipo poliéster. Esses materiais foram utilizados para dois fins distintos, a aplicação em sistemas de Drug Delivery e em sistemas catalíticos. Em relação aos sistemas de Drug Delivery, foram estudados dois aspectos principais: (i) Impregnação de fármacos na matriz dendrimérica utilizando scCO2 como solvente - foi estudado o comportamento dos materiais frente ao solvente neotério em termos de estrutura (arquitetura da macromolécula), grupos modificadores (acetonida, hidroxila, acetila e cadeia lineares de polilactato) e densidade do solvente. Os materiais que apresentaram características adequadas foram utilizados no estudo da impregnação de fármacos modelo (Ibuprofeno e Fluconazol) na matriz dendrimérica, utilizando-se scCO2 como solvente. Ambos os fármacos foram eficientemente aprisionados no interior da matriz e apresentaram interações com sua estrutra (analisadas por espectroscopia Raman e 1H RMN). (ii) Estudo do potencial para uso como nanocarreadores em Drug Delivery destinados as vias aéreas - Estudou-se o emprego dos dendrímeros do tipo poliéster de diferentes gerações (G3 e G4) modificados com um marcador fluorescente (FITC), conjugados ou não a poli(etilenoglicol) (PEG), como potenciais nanocarreadores para sistemas de Drug Delivery destinados as vias aéreas. Foram realizados testes in vitro para avaliar o transporte e a internalização desses materiais em um modelo de epitélio pulmonar (monocamada de células Calu-3). O transporte e internalização se mostraram dependentes do tamanho da espécie, sendo que dendrímeros conjugados com PEG apresentaram baixa internalização e mais eficiente transporte através da monocamada, situação oposta à ocorrida com os dendrímeros não conjugados. Estudou-se a degradabilidade desses materiais em condições de pH de relevância biológica, assim como a citotoxicidade dos dendrímeros íntegros e de seus fragmentos frente às células Calu-3, sendo que todas as espécies demonstraram baixa toxicicidade na faixa de concentração estudada. O dendrímero modificado com PEG foi utilizado em uma formulação do tipo \"pressurized metered-dose inhaler\" (pMDI). A performance do aerossol obtido com o pMDI foi avaliada, in vitro, através de um impactador de cascata de Andersen (Andersen Cascade Impactor, ACI), mostrando excelentes resultados, com ao redor de 90% da formulação atingindo regiões profundas do pulmão (eg. alvéolos). Em relação à aplicação em sistemas catalíticos, poliésteres hiperramificados, similares aos dendrímeros empregados nos demais estudos, foram modificados de modo a se obter grupos -NH2 terminais e utilizados para magnificação de performance de catalisadores baseados em ródio. Os poliésteres hiperramificados modificados foram imobilizados em nanopartículas ferromagnéticas, do tipo Fe3O4@SiO2, a fim de se obter uma elevada densidade de grupos aminos terminais, os quais foram posteriormente modificados e serviram de ancoragem para um catalisador de Rh. Foi avaliado o incremento do conteúdo de metal na nanopartícula (de 0,2% para 1,0% m/m), assim como seu efeito catalítico em reações de hidroformilação. / Highly specific materials (polyfunctional) continue to be key candidates to address the challenges of technological and biological fields. Aiming to reach different applications, polyester dendritic structures (dendrimers and hyperbranched polymers) were synthesized. These materials were used in two different ways, application in Drug Delivery systems and in catalytic systems. Regarding the usage in the Drug Delivery systems, two major aspects were studied: (i) Impregnation of drugs in the dendrimeric matrix using scCO2 as solvent - It was studied the behavior of these materials in the neoteric solvent in terms of structure (architecture of the macromolecule), modifying groups (acetonide, hydroxyl, acetyl and linear polylactide chains) and density of the solvent. The materials that showed appropriate characteristics were used for the impregnation of model drugs (Ibuprofen and Fluconazole) in the dendrimeric matrix, using scCO2 as solvent. The two drugs were efficiently trapped in the matrix, and showed interactions with its structure (analyzed by Raman Spectroscopy and 1H NMR) (ii) Study of potential usage as nanocarriers in Drug Delivery systems for the airways - It was studied the application of polyester dendrimers of different generations (G3 and G4), labeled with FITC and conjugated or not with polyethylene glycol (PEG) as potentials nanocarriers for Drug Delivery systems for the airways. In vitro tests were performed to analyze the transport and internalization of these materials in a model of lung epithelia (Calu-3 monolayer). Transport and internalization showed to be size dependent, where the PEGylated dendrimers showed low internalization and more efficient transport through the monolayer, with the opposite situation for the non-conjugated dendrimers. The degradation of the materials was studied in biological relevant values of pH, as well the cytotoxicity on Calu-3 of the dendrimers and their building-blocks. All materials showed very low cytotoxicity in the range of concentrations used. The G4 PEGylated dendrimer was used to prepare a pMDI (pressurized metered-dose inhaler) formulation. The performance of the resulting aerosol was evaluated, in vitro, using an eight stage Andersen Cascade Impactor (ACI). The results showed excellent deep lung deposition, where almost 90% of the formulation reached deep compartments, as alveoli. In the catalytic system application, hyperbranched polyesters, similar to the employed dendrimers, were modified to incorporate peripheral -NH2 groups and used to magnify the catalytic effect of Rhodium-based catalysts. The modified hyperbranched polyesters were immobilized on magnetic nanoparticles (Fe3O4@SiO2), resulting in a high density of terminal amine groups. These groups were modified and used for the anchorage of a Rhodium catalyst. It was evaluated the increase in the metal load of the nanoparticles (from 0.2% to 1.0% w/w), as well the catalytic effect in hydroformylation reactions.

Die vorliegende Arbeit behandelt die Entwicklung des genetischen Starrkörper-Algorithmus (rigid body genetic algorithm, RGBA), und seine Anwendung zur Untersuchung der Kohlenwasserstoff-Adsorption auf der MgO (001) Oberfläche. Die RBGA Methode ist ein modifizierter hybrid-genetischer Algorithmus mit Starrkörper-Optimierung im lokalen Optimierungsschritt. Diese Modifikation führt zu einer großen Vereinfachung des Optimierungsproblems und ermöglicht damit, eine große Anzahl von möglichen Konfigurationen zu analysieren. Die zentrale Annahme der Methode ist, dass die einzelnen Teile des Systems (starrer Körper) während der gesamten globalen Optimierung nicht ihre interne Konfiguration ändern. Daher ist diese Methode ein geeignetes Werkzeug, um Phänomene wie Adsorption zu studieren, in dem alle Teilsysteme - Oberfläche und einzelne Moleküle - ihre interne Struktur bewahren. Der Algorithmus ermöglicht das Auffinden der globalen Minima für die Starrkörper, die dann im nächsten Schritt vollständig optimiert („relaxiert“) werden, um Verformungen aufgrund der Entspannung der Oberfläche und des Adsorbats auszumachen. / The present work was concentrated on developing the Rigid Body Genetic Algorithm (RBGA), and applying it to investigate the hydrocarbon adsorption on the MgO(001) surface. The RBGA method is a modified hybrid genetic algorithm with rigid body optimization at the local optimization step. The modification allows for a vast simplification of the optimization problem, and, in turn, to search a large number of possible configuration. The key assumption of the method is that individual parts of the system (rigid bodies) do not change their internal configuration throughout the global optimization. Therefore, this method is a perfect tool to study phenomena like adsorption, where all the subsystems – surface and individual molecules – preserve their internal structure. The algorithm allows to obtain global minima, which then can be fully optimized and to account for deformations due to the relaxation of the surface and adsorbate molecules.

Die effiziente Nutzung der begrenzten Ressourcen auf der Erde ist ein entscheidender Faktor für ein nachhaltiges Leben. Die Entwicklung besserer Katalysatoren kann dabei einen wesentlichen Beitrag leisten. Ein umfassendes Verständnis der katalytischen Reaktivität würde es ermöglichen, spezifische katalytische Eigenschaften zu konzipieren und zu kontrollieren. In diese Arbeit wurde die Korrelation der Katalysatoroberfläche mit den Adsorptionswärmen von Molekülen aus der Gasphase untersucht. Insbesondere wurde die Adsorptionwärme von CO auf Pd-Partikeln als Funktion der Partikelgröße mittels gut charakterisierte Modelkatalysatorsysteme, eisenoxidgeträgerte Pd-Partikel, und UHV-Einkristalladsorptionskalorimetrie bestimmt. Es konnte die langjährige Kontroverse, wie sich die Adsorptionswärme von CO auf Pd mit der Partikelgröße ändert, aufgelöst werden. Die Adsorptionswärmen wurden für CO auf geträgerten Pd-Partikeln mit mittleren Größen zwischen 1.8 und 8 nm, sowie Pd(111) untersucht. Es zeigte sich dabei, dass die Anfangsadsorptionsenergie mit abnehmender Partikelgröße kleiner wird. Das Mikrokalorimeterexperiment besteht aus einer Präparationskammer und einer Kalorimetriekammer, die sowohl die Präparation und Charakterisierung von geträgerten metallischen Nanopartikeln, als auch Adsorptionsenergiemessungen ermöglichen. Das Kalorimeter basiert auf dem Design von Campbell et al. und nutzt eine pyroelektrische Folie als Detektor. Es wurden Verbesserungen in Bezug auf Ausrichtung, Temperaturstabilität und Vibrationsisolation implementiert. Ein gepulster Molekularstrahl wird eingesetzt, um die Oberfläche einem stabilen und homogenen Fluss von Gasphasenmolekülen auszusetzten. Desweiteren erlaubt ein In situ Reflektivitätsmessaufbau die Bestimmung der optischer Eigenschaften von Modelkatalysatoroberflächen, was entscheidend für eine akkurate Energiekalibration des Kalorimeters ist. / The efficient use of the limited resources on earth is a critical factor to sustainable life. The development of better catalysts can make a significant contribution. Complete understanding of the catalytic activity would facilitate the design and control of specific catalytic processes. In this work, the correlation of the catalyst structure and the heats of adsorption of gas-phase particles were investigated. In particular, the heat of adsorption for CO on Pd particles was determined as a function of particle size, using a well-characterized model catalyst system, Pd particles supported on an iron oxide film, and UHV single crystal adsorption microcalorimetry. It was possible to resolve the longstanding controversy, how the heat of adsorption of CO on Pd particles changes with particle size. The heat of adsorption for CO on Pd particles was studied on supported Pd particles with a mean diameter of 1.8 to 8 nm and Pd(111). The initial heat of adsorption was found to decrease with decreasing particle size. The completed microcalorimeter experiment comprises a preparation chamber and a calorimetry chamber, providing all means to prepare and characterize oxide supported metal nanoparticles and to perform adsorption energy measurements. The calorimeter is based on the design of Campbell et al., using a pyroelectric ribbon as a detector. Improvements with respect to alignment, temperature stability, and vibration isolation were implemented. A pulsed molecular beam is used to expose the surface to a stable and homogeneous flux of gas-phase molecules. Further, a dedicated in situ reflectivity measurement setup allows optical characterization of the model catalyst surfaces, which is crucial for an accurate energy calibration of the calorimeter.

Materiais altamente especializados (polifuncionais) continuam a ser candidatos chave para avanços na área tecnológica e biológica. Buscando aplicação em campos diversos, foram sintetizadas estruturas dendríticas (dendrímeros e polímeros hiperramificados) do tipo poliéster. Esses materiais foram utilizados para dois fins distintos, a aplicação em sistemas de Drug Delivery e em sistemas catalíticos. Em relação aos sistemas de Drug Delivery, foram estudados dois aspectos principais: (i) Impregnação de fármacos na matriz dendrimérica utilizando scCO2 como solvente - foi estudado o comportamento dos materiais frente ao solvente neotério em termos de estrutura (arquitetura da macromolécula), grupos modificadores (acetonida, hidroxila, acetila e cadeia lineares de polilactato) e densidade do solvente. Os materiais que apresentaram características adequadas foram utilizados no estudo da impregnação de fármacos modelo (Ibuprofeno e Fluconazol) na matriz dendrimérica, utilizando-se scCO2 como solvente. Ambos os fármacos foram eficientemente aprisionados no interior da matriz e apresentaram interações com sua estrutra (analisadas por espectroscopia Raman e 1H RMN). (ii) Estudo do potencial para uso como nanocarreadores em Drug Delivery destinados as vias aéreas - Estudou-se o emprego dos dendrímeros do tipo poliéster de diferentes gerações (G3 e G4) modificados com um marcador fluorescente (FITC), conjugados ou não a poli(etilenoglicol) (PEG), como potenciais nanocarreadores para sistemas de Drug Delivery destinados as vias aéreas. Foram realizados testes in vitro para avaliar o transporte e a internalização desses materiais em um modelo de epitélio pulmonar (monocamada de células Calu-3). O transporte e internalização se mostraram dependentes do tamanho da espécie, sendo que dendrímeros conjugados com PEG apresentaram baixa internalização e mais eficiente transporte através da monocamada, situação oposta à ocorrida com os dendrímeros não conjugados. Estudou-se a degradabilidade desses materiais em condições de pH de relevância biológica, assim como a citotoxicidade dos dendrímeros íntegros e de seus fragmentos frente às células Calu-3, sendo que todas as espécies demonstraram baixa toxicicidade na faixa de concentração estudada. O dendrímero modificado com PEG foi utilizado em uma formulação do tipo \"pressurized metered-dose inhaler\" (pMDI). A performance do aerossol obtido com o pMDI foi avaliada, in vitro, através de um impactador de cascata de Andersen (Andersen Cascade Impactor, ACI), mostrando excelentes resultados, com ao redor de 90% da formulação atingindo regiões profundas do pulmão (eg. alvéolos). Em relação à aplicação em sistemas catalíticos, poliésteres hiperramificados, similares aos dendrímeros empregados nos demais estudos, foram modificados de modo a se obter grupos -NH2 terminais e utilizados para magnificação de performance de catalisadores baseados em ródio. Os poliésteres hiperramificados modificados foram imobilizados em nanopartículas ferromagnéticas, do tipo Fe3O4@SiO2, a fim de se obter uma elevada densidade de grupos aminos terminais, os quais foram posteriormente modificados e serviram de ancoragem para um catalisador de Rh. Foi avaliado o incremento do conteúdo de metal na nanopartícula (de 0,2% para 1,0% m/m), assim como seu efeito catalítico em reações de hidroformilação. / Highly specific materials (polyfunctional) continue to be key candidates to address the challenges of technological and biological fields. Aiming to reach different applications, polyester dendritic structures (dendrimers and hyperbranched polymers) were synthesized. These materials were used in two different ways, application in Drug Delivery systems and in catalytic systems. Regarding the usage in the Drug Delivery systems, two major aspects were studied: (i) Impregnation of drugs in the dendrimeric matrix using scCO2 as solvent - It was studied the behavior of these materials in the neoteric solvent in terms of structure (architecture of the macromolecule), modifying groups (acetonide, hydroxyl, acetyl and linear polylactide chains) and density of the solvent. The materials that showed appropriate characteristics were used for the impregnation of model drugs (Ibuprofen and Fluconazole) in the dendrimeric matrix, using scCO2 as solvent. The two drugs were efficiently trapped in the matrix, and showed interactions with its structure (analyzed by Raman Spectroscopy and 1H NMR) (ii) Study of potential usage as nanocarriers in Drug Delivery systems for the airways - It was studied the application of polyester dendrimers of different generations (G3 and G4), labeled with FITC and conjugated or not with polyethylene glycol (PEG) as potentials nanocarriers for Drug Delivery systems for the airways. In vitro tests were performed to analyze the transport and internalization of these materials in a model of lung epithelia (Calu-3 monolayer). Transport and internalization showed to be size dependent, where the PEGylated dendrimers showed low internalization and more efficient transport through the monolayer, with the opposite situation for the non-conjugated dendrimers. The degradation of the materials was studied in biological relevant values of pH, as well the cytotoxicity on Calu-3 of the dendrimers and their building-blocks. All materials showed very low cytotoxicity in the range of concentrations used. The G4 PEGylated dendrimer was used to prepare a pMDI (pressurized metered-dose inhaler) formulation. The performance of the resulting aerosol was evaluated, in vitro, using an eight stage Andersen Cascade Impactor (ACI). The results showed excellent deep lung deposition, where almost 90% of the formulation reached deep compartments, as alveoli. In the catalytic system application, hyperbranched polyesters, similar to the employed dendrimers, were modified to incorporate peripheral -NH2 groups and used to magnify the catalytic effect of Rhodium-based catalysts. The modified hyperbranched polyesters were immobilized on magnetic nanoparticles (Fe3O4@SiO2), resulting in a high density of terminal amine groups. These groups were modified and used for the anchorage of a Rhodium catalyst. It was evaluated the increase in the metal load of the nanoparticles (from 0.2% to 1.0% w/w), as well the catalytic effect in hydroformylation reactions.

Afin de réduire la teneur en soufre des essences, l’hydrodésulfuration transforme les molécules soufrées en hydrocarbures en présence d’un catalyseur supporté (métaux de transition sulfurés : MoS2) et dopé (Co, Ni). Cette phase active, déposée sur des nanoparticules, présente un nombre plus important de défauts, sites actifs essentiels à la catalyse. Les nanoparticules ont un ratio S/V élevé, une grande réactivité de surface avec une juste utilisation des quantités de métaux. L’objectif de ce projet de thèse est de synthétiser des catalyseurs nanométriques de type coeur@coquille possédant une meilleure activité catalytique qu’un simple mélange mécanique de deux métaux sulfurés. Le coeur est composé de Fe3O4 ou de nanodiamants et la coquille de MoS2, NiMoS, CoMoS ou NiCoMoS, supporté sur du TiO2 ou de la γ-Al2O3. Une réaction modèle (HDS du thiophène) a été utilisée afin d’évaluer l’activité catalytique et d’optimiser la structure du catalyseur. L’étude portera sur les paramètres de synthèse et l’effet de la taille du coeur, la synthèse utilisée, les interactions entre le coeur et la coquille, le support, la (co)– promotion (Ni/Co) et l’activation par la température. / In hydrodesulfurization of fossil fuels, the sulfur levels are reduced by sulfur extraction from hydrocarbons by using supported catalysts (MoS2), doped (Co, Ni). Ultra-deep hydrodesulfurization will be achieved by improving new catalysts. Nanoparticles are a promising candidate with their high S/V ratio and permit to use the precise amount of metallic sulphide. The aim of this thesis is the synthesis of core@shell nanometric catalyst with improved activities. Core composed of Fe3O4 or nanodiamonds will be surrounded by a shell formed of MoS2, NiMoS, CoMoS or NiCoMoS, supported on TiO2, γ-Al2O3. Model reaction (thiophene) has allowed to compare conversion rates between each catalyst. Additionally, characterizations have provided a better understanding of the HDS catalyst structure and performances. Some factors have been investigated such as the size of the core, theinteractions between the core and the shell, the type of synthesis, the support chosen, the synergetic effect with doping ions and also the activation of the catalyst at low temperature.

Made available in DSpace on 2014-12-17T15:42:16Z (GMT). No. of bitstreams: 1 LuizaPFCG_TESE.pdf: 3362653 bytes, checksum: 0de0a428d24980a5f9b2bf94d2e9214f (MD5) Previous issue date: 2012-08-23 / To overcome the challenge of meeting growing energy demand in a sustainable way, biodiesel has shown very promising as alternative energy can replace fossil fuels, even partially. Industrially, the biodiesel is produced by homogeneous transesterification reaction of vegetable oils in the presence of basic species used as catalysts. However, this process is the need for purification of the esters obtained and the removal of glycerin formed after the reaction. This context, the alternative catalysts have that can improve the process of biodiesel production, aiming to reduce costs and facilitate its production. In this study, the AlSBA-15 support with Si / Al ratio = 50 was synthesized, as like as the heterogeneous catalysts of zinc oxide and magnesium supported on mesoporous AlSBA-15 silica, in the concentrations of 5, 10, 15 and 30 %, relative to the support. The textural properties and structural characterization of catalysts and supports were determined by techniques: X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) coupled to the chemical analyzer, adsorption / desorption of N2, thermal analysis (TG / DTG), absorption spectroscopy in the infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). Characterization results indicated that the support AlSBA-15 retained the hexagonal ordered after the incorporation of zinc oxide and magnesium oxide in the holder. For heterogeneous catalysts, ZnO-AlSBA-15, that was observed the presence of zinc oxide nanoparticles dispersed in the surface and interior channels of the mesoporous and microporous support. The catalytic activity was evaluated by the transesterification reaction of sunflower oil via methylic route, and some reaction parameters were optimized with the most active catalyst in biodiesel production by sunflower oil. For the series of heterogeneous catalysts, the sample with 30 % ZnO supported on AlSBA-15 showed a better conversion of triglyceride to methyl esters, about 95.41 % of reaction conditions: temperature 175 ?C, with molar ratio of 42:1, stirring at 200 rpm and under a pressure of 14 bar for 6 h. The catalyst MgO-AlSBA-15 showed no catalytic activity in the studied reactions / Para superar o desafio de atender a crescente demanda por energia de forma sustent?vel, o biodiesel tem se demonstrado bastante promissor como alternativa energ?tica, que possa substituir os combust?veis fosseis, mesmo que parcialmente. Industrialmente, o biodiesel ? produzido atrav?s de rea??o homog?nea de transesterifica??o de ?leos vegetais na presen?a de esp?cies b?sicas utilizadas como catalisadores. Entretanto, este processo h? a necessidade de purifica??o dos ?steres obtidos e a remo??o da glicerina formada ap?s a rea??o. Diante deste contexto, tem-se buscado catalisadores alternativos, que possa aprimorar o processo de produ??o de biodiesel, visando diminuir os custos e facilitar a sua produ??o. Neste trabalho, foram sintetizados o suporte AlSBA-15 na raz?o Si/Al = 50, e os catalisadores heterog?neos de ?xido de zinco e de magn?sio suportado sobre s?lica mesoporosa AlSBA-15, nas concentra??o de 5, 10, 15 e 30 %, com rela??o ao suporte. As propriedades texturais e a caracteriza??o estrutural dos catalisadores e do suporte foram determinadas pelas t?cnicas de: difratometria de raios X (DRX), microscopia eletr?nica de varredura (MEV), microscopia eletr?nica de transmiss?o (MET) acoplada ao analisador qu?mico, adsor??o/dessor??o de N2, an?lise t?rmica (TG/DTG), espectroscopia de absor??o na regi?o do infravermelho (FTIR) e espectroscopia fotoeletr?nica de raios X (XPS). Os resultados de caracteriza??o indicaram que o suporte AlSBA-15 preservou a estrutura hexagonal ordenada, ap?s a incorpora??o do ?xido de zinco e do ?xido de magn?sio no suporte. Em rela??o aos catalisadores heterog?neos, ZnO-AlSBA-15, observou-se a presen?a de nanopart?culas de ?xido de zinco dispersas na superf?cie e no interior dos canais microporosos e mesoporosos do suporte. A atividade catal?tica foi avaliada pela rea??o de transesterifica??o do ?leo de girassol via rota met?lica, e alguns par?metros reacionais foram otimizados com o catalisador mais ativo na produ??o de biodiesel pelo ?leo de girassol. Para as s?ries de catalisadores heterog?neos, a amostra com 30 % ZnO suportado na AlSBA-15 apresentou melhor convers?o dos triglicer?deos em ?steres met?licos, cerca de 95,41 %, nas condi??es reacional de: temperatura de 175 ?C, com raz?o molar de 42:1, em agita??o de 200 rpm e sob press?o de 14 bar durante 6 h. O catalisador MgO-AlSBA-15 n?o apresentou atividade catal?tica nas rea??es estudadas

Dans le contexte actuel de développement de nouvelles sources d'énergie non fossiles tout en minimisant l'impact environnemental, la production de carburants solaires par la valorisation des émissions anthropiques de CO2 apparaît comme une solution à fort potentiel. Le principal défi dans les processus artificiels photo-induits concerne le caractère bidimensionnel des systèmes utilisés, en raison de la faible profondeur de pénétration des photons. Ce travail de thèse se concentre sur le développement de mousses solides alvéolaires, issues de la chimie intégrative, présentant une porosité hiérarchiquement organisée. A travers l’imprégnation de précurseurs de TiO2, des photocatalyseurs autosupportés ont été synthétisés et ont montré une augmentation de la pénétration des photons d’un ordre de grandeur. D’autre part, ces solides limitent les réactions inverses par un effet de dilution, tout en assurant une sélectivité élevée envers la génération d'alcanes. Un modèle cinétique, basé sur un formalisme mixte de Langmuir-Hinshelwood et Eley-Rideal, est proposé pour décrire le comportement des matériaux. / In the current context of developing novel non-fossil energy sources while minimizing the environmental impact, solar-driven-fuel-production by exploiting anthropogenic CO2 emissions appears to be a solution with great potential. The main challenge in artificial photo-induced processes concerns the two-dimensional character of the systems used, due to the low photon penetration depth. This thesis work focuses on the development of alveolar solid foams, derived from integrative chemistry and bearing a hierarchically organized porosity. By TiO2 precursor impregnation, self-standing photocatalysts were synthesized and provided a photon penetration increase by an order of magnitude. Moreover, these solids limit back-reactions by a dilution effect, while ensuring high selectivity towards alkane generations. A kinetic model, based on a mixed formalism of Langmuir-Hinshelwood and Eley-Rideal, is proposed to describe material behavior.