Ce travail de recherche portant sur la compréhension des premières étapes de synthèse des zéolithes s'inscrit dans le cadre général de développements efficients de nouveaux catalyseurs performants. De nombreuses incertitudes demeurent quant aux mécanismes moléculaires de leur formation, en particulier lors de la nucléation en conditions de synthèse hydrothermale. Dans ce contexte, une méthodologie globale a été proposée afin d'évaluer l'impact des variables de synthèse sur la formation des espèces siliciques. La réalisation de ce travail a nécessité l'usage de différentes méthodes théoriques, combinant des calculs ab initio DFT et des simulations kMC. Un nouveau module kMC nommé Réacdiff a ainsi été développé et validé avec le modèle Lodka. L'extension des chemins réactionnels vers des espèces plus complexes a été effectuée et le recours à des modèles théoriques du type Brønsted-Evans-Polanyi (BEP) a été indispensable afin de les estimer rapidement. Un nouveau modèle des étapes réactionnelles d'oligomérisation a été proposé et a permis de tester l'effet crucial des agents organiques structurants (AS). Ces travaux ont permis de donner un nouveau regard sur la compréhension de la condensation des espèces siliciques durant les premières étapes de la synthèse des zéolithes. / This research work on the understanding of the early stages of zeolites synthesis fits withinthe general framework of the technological lock on the lower cost of new efficient catalysts synthesisoptimization. Many uncertainties remain with respect to the molecular mechanisms of their formation,in particular during nucleation in hydrothermal synthesis conditions. In this context, a comprehensivemethodology was proposed to assess the impact of synthesis variables in the formation of silicicspecies. This objective has required the use of different theoretical methods, combining ab initio DFTcalculations and kMC simulations. The creation of a new kMC module named Reacdiff has beendeveloped and validated with the Lodka model. The extension of reaction pathways to more complexspecies was carried out with the essential use of theoretical models like Brønsted-Evans-Polanyi(BEP) to quickly estimate. A new anionic model of the reaction steps of oligomerization has beenproposed and has allowed testing the crucial effect of organic templates. These thesis works gave anew understanding on the condensation of silicic species in early stages of zeolite synthesis.

Abstract The aim of the thesis is to expand the knowledge of the catalytic properties of platinum-loaded zeolite catalysts in the reduction of NOx by hydrocarbons. The work is divided into three parts. First the recent literature of zeolite catalysts has been introduced, secondly the adsorption capacity, activity, and acidity of the catalysts have been studied by TPD and IR techniques, and thirdly the derived reaction mechanisms based on the obtained data are presented. Parent and 1 wt-% Pt-loaded ZSM-5, Beta, Y, and Ferrierite zeolite catalysts have been studied in the C3H6-assisted reduction of NO. The Pd/Al2O3-based catalyst was used as a reference material for the reaction mechanistic studies. Several experimental techniques (in situ DRIFT, activity measurements, CO chemisorption, N2 physisorption, TPD, and TEM) have been used for the characterisation of the catalysts properties. The IR technique was used as the main technique for the determination of activities, surface species, and the acidic properties of the zeolite-based catalysts. The activity studies carried out by the gaseous FTIR technique provide information on the desired reaction products as well as the undesired by-products. The detection and identification of the surface species as well as the reaction intermediates formed were done by the DRIFT method. The activity experiments indicate the effectiveness of the Pt-loaded zeolite catalysts. The reduction of NO was found to decrease in the order: Pt/Beta > Pt/Y > Pt/Ferrierite > Pt/ZSM-5 in the conditions with excess O2. Platinum can be concluded to have an effect on O2 and NO dissociation. Oxidation reactions of NO to NO2 and propene to CO2 were observed to be more intense over the platinum-loaded zeolites than over the parent zeolites. In this work the reaction mechanisms for the C3H6-SCR of NO were derived over the Pt-loaded zeolite as well as the Pd/alumina catalysts based on the data obtained by DRIFT and activity experiments. The kinetics for the NO reduction by CO over Pd/Al2O3 was also derived. With the methods employed, the mechanistic steps over the Pt-loaded zeolites and Pd/Al2O3-based catalysts could be derived quite precisely and easily for C3H6-SCR of NO. Reaction routes were determined to go via different formations of intermediates over the two catalysts, i.e. via organonitrogen and isocyanate routes, respectively. The IR techniques were discovered to be effective tools in applied engineering studies.

Les exploitations d’argiles kaoliniques réfractaire d’Água Limpa/Brésil et de kaolins de couchage de Rio Capim/Brésil laissent des résidus d’exploitation en très grands tonnages. Dans la perspective d’une valorisation plus complète assurant un développement durable de l’industrie extractive, on a envisagé d’utiliser ces argiles résiduelles dans la fabrication de zéolites. On a obtenue dès une durée de synthèse de 24h, une zéolite 4A très proche de sa définition théorique. Le rendement de synthèse est meilleur avec les produits de Rio Capim. Le volume nanoporeux de la zéolite 4A est inaccessible à l’azote mais accessible à la molécule d’eau. Les zéolites synthétisées ont été testées comme adsorbants cationiques pour le cuivre, le plomb, le cadmium, le zinc, le magnésium, potassium et mercure. La rétention a voisine 60% du remplissage théorique pour toutes les espèces testées, sauf pour le cuivre où elle dépasse la capacité théorique et pour le mercure où elle est très faible. / Working Kaolinic refractory clays from Água Limpa (Minas Gerais) and paper coating kaolins from Rio Capim (Pará) - Brazil throw over very large amounts of mining residues. With the outlook of a more complete beneficiation, aiming at a sustainable development of mineral industry, the use of these residual clays has been considered for manufacturing zeolites. For a synthesis time of only 24h, a zeolite 4A very close to its theoretical definition is obtained.The nano-porous volume of the zeolite 4A is inaccessible to nitrogen molecules, but accessible to water molecules. Synthesised zeolites have been tested as cationic adsorbents of Cu, Pb, Cd, Zn, Mg, K and Hg. The retention is better for materials derived from Rio Capim Kaolins. The retention is close to 60% of the theoretical completion of the exchange capacity in all cases, except for copper for which the retention exceeds the capacity, and mercury for which the retention is very low.

L’échantillonnage passif est une alternative prometteuse à l’échantillonnage ponctuel. Cette technique permet d’accumuler les contaminants présents dans l’eau directement in-situ, intégrant ainsi les variations de concentrations temporelles qui ne sont pas détectables avec l’échantillonnage ponctuel. Cependant la plupart des échantillonneurs commercialisés actuellement utilisent des phases complexes et coûteuses. Ces travaux de thèse ont pour objectif de mettre au point un nouvel échantillonneur intégratif plus robuste et moins coûteux, capable d’échantillonner autant les contaminants métalliques que les composés organiques. Pour cela, l’idée était d’utiliser comme phase adsorbante un minéral naturel poreux doté de fortes capacités d’adsorption ; des zéolithes et une sépiolite naturelle ont été envisagées. Le développement d’un tel dispositif est un processus complexe qui passe tout d’abord par l’étude des capacités d’adsorption des différents solides pour les contaminants métalliques ainsi que pour les composés organiques. La comparaison des capacités d’adsorption des différents solides démontre que la sépiolite est la plus efficace pour la rétention de la majorité des contaminants étudiés. Sur la base de ces résultats la sépiolite est sélectionnée comme phase réceptrice du nouvel échantillonneur. Le déploiement de ces nouveaux dispositifs dans un milieu semi-contrôlé soumis à différents scénarios de contamination met en lumière une importante capacité d’échantillonnage tant pour les métaux que pour les contaminants organiques hydrophiles. Enfin, dans une dernière étape. / Passive sampling is a promising alternative to grab sampling. This approach consists in accumulating contaminants from water directly in-situ. Contrary to conventional grab sampling, this method allows integrating the temporal variations of the concentration. However most commercial samplers use complex and expensive adsorbent phases. In this work, we aimed to develop a new integrative sampler, more robust and less expensive than the commercial ones, able to sample both metals and organic compounds. For this the use of porous natural minerals with high adsorption capacities was investigated. Zeolites and natural sepiolite were considered. The development of this kind of device is a complex process involving a double approach laboratory/field. The first step consists in studying the adsorption capacity of different solids towards metals and organic compounds. The comparison of adsorption efficiency of different solids shows that sepiolite is the most efficient for the retention of most of the studied contaminants. Based on these results, it was selected as receiving phase of the new sampler. Deployment of these new devices in a semi-controlled environment with various scenarios of contamination was tested. This experiment highlighted that sepiolite has an important sampling ability both for metals and for hydrophilic organic contaminants. Finally, the last step of this process consisted in a validation of these samplers in a natural environment and in industrial effluent.

Sick building syndrome (SBS) is a particular concern in places with inadequate ventilation and frequently attributed to chemical contaminants such as volatile organic compounds (VOCs)released from indoor sources that are frequently encountered in everyday life such as adhesives, carpeting, upholstery, manufactured wood products, copy machines, pesticides, cleaning agents inside buildings, plumbing vents, and painting. Furthermore, it is a major issue for modern human beings who spend most of their time indoors or must stay indoors for self-isolation due to special circumstances such as the coronavirus disease-19 (COVID-19) pandemic that occurred in 2019 and 2020. Main indoor VOCs are trichloroethylene (TCE), benzene, toluene, and para-xylene (p-xylene). In general, these compounds are not present in indoor spaces at acute concentrations, but prolonged exposure to these compounds can have chronic health effects such as allergic sensitization, increased cancer risks, and respiratory diseases. In this study, the adsorption process with various advantages has been applied to remove VOC’s using commercially available hydrophobic adsorbents. The hydrophobic adsorbents can contribute to reducing the possibility of chemical adsorption (chemisorption) of moisture from the air, which can decrease the capacity of adsorbent by clogging the pores. The adsorption of these major VOCs was investigated in this work for three major types of industrial hydrophobic adsorbents: activated carbons, zeolites, and polymer. This study will show the investigation into finding the most promising hydrophobic adsorbent for removal of TCE, benzene, toluene, and p-xylene, which are the main VOCs found indoors. The promising hydrophobic adsorbent has been determined by comparing Henry’s law constants and heat of adsorption values for the different adsorbents, which were estimated by using a concentration pulse chromatographic technique by utilizing a gas chromatograph equipped with a flame ionization detector. For all adsorbents, Henry’s law constants at room temperature of p-xylene were always the highest followed by toluene, benzene, and TCE. For all adsorbates, Henry’s law constants at room temperature of AC BPL and HiSiv 3000 were higher than the other hydrophobic adsorbents. For a developing modern society dealing with a pandemic, this study can contribute to producing the optimized gas masks and indoor filters for the removal of indoor air pollutants, which can help people who suffer from SBS. It can also help society for taking preventative actions towards dealing with SBS.

L’objectif de cette thèse est d’étudier l’influence de l’architecture poreuse de zéolithes à porosité multimodale sur la sélectivité de catalyseurs dans l’hydrocraquage de charges lourdes, et aussi d’établir des relations prédictives propriétés/performances des matériaux catalytiques.Plusieurs séries de matériaux modèles possédant des réseaux mésoporeux secondaires différents ont été préparés par traitement alcalin de zéolithes de référence de type faujasite, par dessilication et par recristallisation en présence d’agent structurant organique. Les différentes méthodes de structuration de la mésoporosité ont été comparées et discutées en termes de rendements de synthèse des matériaux micro-mésoporeux, de volumes mésoporeux créés, de distribution de tailles des mésopores et de leur co-localisation avec les micropores. Des catalyseurs bifonctionnels ont ensuite été préparés par introduction d'une fonction hydrogénante/déshydrogénante, et utilisés pour l’hydroconversion du n-hexadecane et du squalane.L'activité des catalyseurs, exprimée par la vitesse de réaction à 230°C dans la conversion dun-hexadecane, et à 210°C dans celle du squalane, est linéairement corrélée au nombre de sites acides forts de la zéolithe.Quel que soit le mode de restructuration du réseau mésoporeux et l'architecture de celui-ci, une augmentation du volume mésoporeux conduit à un gain de sélectivité en isomères, produits primaires de réaction, et de symétrie de la distribution de produits de craquage. La sélectivité des catalyseurs, caractérisée par le rendement maximum en isomères, est gouvernée par le transfert de matière au sein des cristaux zéolithiques. Une corrélation directe entre le coefficient de diffusion effectif du n-hexane et la sélectivité des catalyseurs a été établie. / The objective of this thesis is to study the influence of the porous architecture of zeolites with multimodal porosity on the selectivity of catalysts in the hydrocracking of heavy feedstock and also to establish predictive relations between properties and performances of catalytic materials.Several series of model materials possessing different secondary mesoporous networks have been prepared by treating in alkaline medium faujasite reference zeolites either by desilication and or by recrystallization in the presence of an organic structuring agent. The different mesoporosity structuring methods were compared and discussed in terms of yields, created mesoporous volumes, mesopore size distribution and their co-localization with micropores. Bifunctional catalysts were then prepared by introducing a hydrogenating/dehydrogenating function and used for the hydroconversion of n-hexadecane and squalane.The activity of the catalysts, expressed as the reaction rate at 230°C in the conversion ofn-hexadecane and at 210°C in the case of squalane, is linearly correlated with the number of strong acid sites of the zeolite. Whatever the restructuring process of the mesoporous network and its architecture, an increase in the mesoporous volume leads to a higher selectivity into isomers, primary reaction products, and a higher symmetry of the distribution of cracking products. The selectivity of the catalysts, characterized by the maximum yield of isomers, is governed by the transfer of matter within the zeolite crystals. A direct correlation between the effective diffusion coefficient of n-hexane and the selectivity of the catalysts was established.

Les zéolites sont des «tamis moléculaires» connus pour leurs nombreuses applications en adsorption, échange d'ions et catalyse. Dans cette thèse, nous nous sommes concentrés sur l'étude de quelques questions liées à la synthèse et à la post-synthèse de la zéolithe, qui ne sont pas encore résolues par d'autres techniques.La RMN a été l'outil principal dans ce travail, donnant accès à des informations structurales locales sur les nanocristaux même lorsque les techniques de diffraction trouvent leurs limites. Elle peut également être utilisée pour étudier la porosité en utilisant l'adsorption de molécules sondes, et en particulier, le xénon est connu comme une bonne molécule pour cet objectif. En effet, l'isotope 129Xe peut être hyperpolarisé pour augmenter la sensibilité de détection, et il présente une large plage de déplacement chimique en fonction du confinement et donc de la porosité du matériau étudié.(I) Dans la première étude, les étapes initiales de la cristallisation de nano-faujasite (FAU) ont été étudiées en utilisant la RMN classique (principalement par 29Si et 23Na MAS RMN) et la RMN avancée (129Xe). RMN HP). Il a été montré que la cristallisation commence à des stades de synthèse bien antérieurs à ceux observés par d'autres techniques classiques (XRD, SEM, adsorption de N2 ...). La première SBU semble être les prismes hexagonaux, avant les cages sodalite, qui forment rapidement un environnement confiné puis des supercages. De plus, il a été démontré par RMN 129Xe HP et 2D EXSY que la zéolithe nano-faujasite présente des cages sodalite ouvertes et une structure plus souple que dans la zéolite de type micro-faujasite.(ii) La seconde étude est une recherche sur les phénomènes de recristallisation survenant au cours du processus de hiérarchisation de la zéolithe et qui pourrait expliquer la distribution homogène des tailles de mésopores. Comme résultat remarquable, il a été montré dans ce travail que lors de la hiérarchisation de la zéolithe bêta avec le TPAOH, la recristallisation conduisait à la formation de minuscules particules de MFI, formées à la surface des mésopores (RMN 1H MAS, RMN 129Xe HP et 2D EXSY). / The zeolites are ‘molecular sieves’ known for their numerous applications in adsorption, ion exchange, and catalysis. In this thesis, we focused on the study of some questions related to zeolite synthesis and post-synthesis, which are not yet resolved by other techniques. NMR was the primary tool in this work, as it gives access to local structural information on nanocrystals even when diffraction techniques found their limits. NMR can also be used to study porosity using probe molecules adsorption, and in particular, xenon is known as a good molecule for this purpose. Indeed, the isotope 129Xe can be hyperpolarized to increase the detection sensitivity, and interestingly it presents a wide chemical shift range depending on its confinement and thus the porosity of studied material. Two studies are reported in this manuscript: (i) In the first study, the initial steps during the crystallization of nano-faujasite (FAU) type materials were investigated using classical NMR (mainly by 29Si and 23Na MAS NMR) and advanced NMR (129Xe HP NMR). It was shown that crystallization starts at much earlier synthesis stages than those observed by other classical techniques (XRD, SEM, N2 adsorption…). The first SBU seems to be the hexagonal prisms, prior to the sodalite cages, which rapidly form confined environment and then supercages. Moreover, it has been proved by 129Xe HP NMR and 2D EXSY that nano-faujasite zeolite presents opened sodalite cages and a more flexible structure than in micro-faujasite zeolite. (ii) The second study is an investigation on the recrystallization phenomena occurring during hierarchization process of zeolite and which could explain the homogenous distribution of the mesopore sizes. As a remarkable result, it has been shown in this work that during the hierarchization of beta zeolite with TPAOH, the recrystallization lead to the formation of tiny MFI particles, formed at the surface of the mesopores (1H MAS NMR, 129Xe HP NMR and 2D EXSY).

Zeolite membranes have great potential in gas separation applications because of their unique selective properties. The main challenge is in synthesizing defect-free zeolite membranes. In this study, we synthesized silicalite-1 zeolite membranes on ceramic supports composed of Al2O3 and TiO2 using the pore-plugging method. We investigated the effect of the fill-level in the autoclave during the synthesis on the membrane performance. In particular, we were interested in determining the conditions at which the defects' contribution to the total transport is minimized. We adopted and further developed the approach proposed by Carter (2019) to quantify the permeance contribution through defects. Comparing the membrane performance before and after calcination, we proposed several modifications to the original analysis of Carter (2019). Knowing the defect transport contribution, we determined the corrected diffusivity, an intrinsic property of zeolite crystals at a given temperature, of several adsorbed gases on silicalite-1 crystals. The defect's contribution decreased as the autoclave fill-level increased from 94 to 98%. A further increase in the autoclave fill-level introduced more defects and caused the autoclave lid to rupture. Despite the differences in the membranes' performance arising from the autoclave fill-level, the corrected diffusivities of CO2, CH4, and N2 in silicalite-1 showed minimal variation from membrane to membrane. This proves the validity of the proposed characterization method. Moreover, the reported corrected diffusivities are comparable to the literature's values, found using other characterization methods. However, none of the previously used methods is as simple and straightforward as the one we further developed in this study.

Phosphorous and nitrogen are vital elements for the well-being of biological life. Industrial discharges, waste water infiltration systems, conventional waste water collection and treatment systems, agricultural runoffs and landfill leachates had been emitting significant quantity of these nutrients into water bodies. These induced negative consequences to the environment including eutrophication of aquatic water bodies, toxicity to marine life and depletion of phosphate resources. Reactive filter technology is developed based on the need to remove and retain nutrients from waste water while improving the quality of effluents from emission sources. Reactive filter materials are used to build filter bed systems that treats domestic waste water, storm water, landfill leachates and contaminated subsurface water to the desired quality. In the past natural minerals such as zeolites and industrially produced polonite had been subject to laboratory study for the sorption of ammonium, heavy metals and phosphorous. The following paper is based on the results of experiment consisting of two columns packed with mordenite and polonite reactive materials filtering in series to reduce NH4 and PO4 content of a waste water. Septic tank effluent pre filtered using 0.45 μm filter is used as influent waste water into the dual columns. The dual column filtered a total of 24.07l s (372PV) and 23.42 ls (496PV) of the waste water. Sampling of the feed water and filtrates of both columns were done every second day with measurement of pH, conductivity and temperature. Analyzed samples confirmed that the dual column filtration resulted in re-moval efficiency of 84.39 % (PO4), 67.98 % (NH4) and -37.762.8 % (NOx). Filtration in the first (mordenite) column resulted in relatively larger proportion of the influent ammonium ion exchange than sorption of phosphate while the filtration in the second (polonite) column sorbed quite high amount of phosphorous than ammonium from effluent of the first column. Saturation of mordenite occurred faster even though there was sorption potential for few more of influent ammonium. All PO4 removal in mordenite column occurred above breakthrough condition. Polonite packed column was in a condition of a third of it’s saturation potential for PO4 removal at the end of the experiment. pH of samples was the parameter which is correlated significantly with filtration in polonite column than temperature and electrical conductivity. The performance of polonite was higher at higher pH than at lower pH. The mean concentrations of the dual column effluent were 0.77 mg-PO4/l and 11.13 mg-NH4/l. This is acceptable by the standards of environmental laws. The result of the experiment is valuable in prediction of performance and designing of real time filter bed.

This thesis presents the recent progress of diffusion measurements in nanoporous host systems by micro-imaging. Interference microscopy is applied as a powerful tool to record transient, intracrystalline concentration profiles of different sorbate species in the porous framework of two different zeolites, viz. ZSM-5 (MFI) and ZSM-58 (DDR). These profiles, yielding high temporal and spatial resolutions of about 10 s and 0.45 μm, follow the change of the refractive index of the host-guest system during uptake and release of certain guest molecules. With the thus accessible changes of concentration and particle fluxes, mass transport parameters, such as intracrystalline diffusivity and surface permeability, can be obtained by the use of the very fundamental equations on diffusion. Additionally, in two examples of never before performed types of experiments, further insights into challenging fields of host-guest interactions are provided: The well known phase transition in MFI type zeolites covering high benzene loadings is investigated in a single crystal study, allowing to follow the change of the sorbate phase in great detail. Furthermore, in DDR zeolites, a new way of data analysis facilitates to study the uptake and release of binary mixtures. Here, from the two-dimension profiles obtained by interference microscopy, the local concentrations of the sorbate species could be retrieved by using the so-called ideal adsorbed solution theory.