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Laponite synthetic clay has been modified via exchange with "A112M7+" (M = Al, Ga, Fe or In) pillaring species and further exchanged after calcination with various metal species. The chemically tailored materials produced have been characterised using powder XRD, thermal analysis, N2 sorption at 77 K, FT-IR and MAS-NMR spectroscopies. Preliminary testing as to their suitability as deNOx catalysts has been carried out both through direct catalytic testing and in-situ FT-IR spectroscopy with NO sorbate. The pillaring species themselves were also investigated through precipitation of their sulphates and characterisation by powder XRD, as synthesised and after heating to 1150&deg;C, thermal analysis and FT-IR and MAS-NMR spectroscopies. None of the "A112M7+ Keggin sulphates" (M = Al, Ga, Fe or In) were single phase materials, all containing the A1137+ Keggin sulphate and at least one other phase. The successful exchange and pillaring of the Laponite parent clay was demonstrated through 27Al MAS-NMR by the observation the of resonance assigned to tetrahedral AlO4. 29Si MAS-NMR showed the presence of both Q3 layer and Q2 edge Si sites and the emergence of a resonance corresponding to Q3 (1OH) Si sites upon exchange of the parent clay. Heating the exchanged material resulted in the disappearance of this resonance, but a further resonance was observed corresponding to Q4(1Al) Si sites, further confirming a successful pillaring reaction. N2 sorption at 77 K gave isotherms consistent with the presence of both micropores and mesopores and specific surface areas in the range 260 m2g-1 < SBET < 360 m2g-1, with Kelvin pore diameters between 35 and 39 A. Upon heating the exchanged clays, no major change in the specific surface area was observed up to 600 &deg;C, with the Kelvin pore diameter reaching a maximum at 400 &deg;C but maintaining at least its original value up to 700 &deg;C. In-situ FT-IR spectroscopy of Co2+-exchanged "A112Fe7+" Laponite in the presence of NO revealed a number of surface species (most notably nitrates, N2O and NO2) and suggestions have been made as to their route of formation. Catalytic testing of a range of materials for N2O destruction in both the presence and absence of CH4 showed a number to achieve 100 % conversion at low reactant flow rates, with the V-exchanged A1137+ Laponite showing the highest potential as a deN2O catalyst.

The main objective of this thesis is to identify a generic approach for the application of ionic liquids to bioconversions. Key factors for the operation of bioconversions in ionic liquids have been identified and product recovery options investigated. Two bioconversions were examined. The first was the hydrolytic resolution of racemic 2,3,4,5-tetrahydro-4-methyl-3-oxo-lH-l ,4-benzodiazepine-2-acetic acid methyl ester (SB-235349) to (2S)-2,3,4,5-tetrahydro-4-methyl-3-oxo-lH-l,4- benzodiazepine-2-acetic acid (SB-240101) by immobilised Candida antarctica lipase B, CALB (Novozyme 435), performed industrially in t-butanol. Initial studies showed this reaction occurred in several ionic liquids with different physico-chemical properties. Simply replacing the organic solvent with an ionic liquid under otherwise identical conditions reduced the rate of conversion and overall yield. The key factors influencing the rate and yield of this bioconversion in ionic liquids were the type of ionic liquid and the substrate solubility, the reaction temperature and the water content. The final optimised reaction in ionic liquids shows an eighteen-fold enhancement in product formation compared to the optimised t-butanol system. In order for ionic liquids to be applied commercially there are still many issues which still need to be resolved these include: the extraction of substrates and products from the ionic liquid media for down stream processing, and the recycle of the media for subsequent reactions. The next step having optimised the CALB bioconversion of SB- 235349 in ionic liquid media was to extract the SB-240101 product and the un-reacted SB-235349 substrate in order to recycle the ionic liquid. The SB-240101 produced by the reaction was removed by liquid-liquid extraction with 50mM bicarbonate buffer (pH 10); overall 93% of the SB-240101 produced was removed from the ionic liquid into the aqueous buffer phase. The un-reacted 2,3,4,5-tetrahydro-4-methyl-3-oxo-lH- 1,4-benzodiazepine-2-acetic acid methyl, ester (SB-240098) was removed by liquid- liquid extraction with isopropyl alcohol, and 91% was removed from the ionic liquid. The ionic liquid was then regenerated with sodium hydroxide for recycle. The results from the bioconversion with fresh and recycled ionic liquid were almost identical, in both cases around l.8g.L-1 of product was produced in 6 hours. The two-phase extractions were subsequently studied in the Lewis cell, and the mass transfer rate (K0) examined for the extraction of both the substrate and the product from the ionic liquid. Values of K0 determined in the Lewis cell over the Reynolds number range for which a flat, non-perturbed, interface could be maintained were in the range 1.0 - 3.5 X 10-6 m.s-1 for both product and substrate extraction. In both extraction experiments there was a linear increase in K0 with Reynolds number. The second bioconversion the thymidine phosphorylase catalysed synthesis of thymidine from thymine, which is traditionally performed in aqueous media, was then examined in ionic liquids. Initial investigations of this conversion step showed that replacing the aqueous media with an ionic liquid like [BMIM][PF6] under otherwise identical reaction conditions reduced the overall yield, which is attributed to the low solubility of the reagents in this ionic liquid. As the first constraint of the aqueous system was the solubility of the substrates and products; work then focused on those ionic liquids that showed a high solubility for thymine and especially thymidine. A study of the conversion in these high solubility ionic liquids showed conversion to the same degree as that demonstrated in aqueous media. An examination of product recovery from [EMIM][tosylate] following the thymidine transformation showed that the most likely method of product recovery was adsorption to an anion exchange resin 1-X8. In summary the results presented in this thesis show that ionic liquids offer significant advantages as alternative reaction media in industrial bioconversions. These are related to the excellent solvation properties of ionic liquids, and the tunable physicochemical properties of ionic liquids such as miscibility (or immiscibility) with water by changes in the anion or cation. Overall this thesis has identified generic procedures for the design of bioconversions and product recovery options in ionic liquids that have been exemplified using two different bioconversion systems.

Suite au caractère fini des réserves de charbon, pétrole et gaz, nous sommes obligés de trouver des alternatives renouvelables pour substituer les ressources fossiles comme source d’énergie et matière première pour l’industrie chimique. Parmi les nombreuses exemples ou la biomasse est déjà utilisé comme alternative aux ressources fossiles, on peut notamment citer le biodiésel. Ce dernier est produit à grande échelle par la transesterification de l’huile végétale. Cependant, le glycérol est formé comme sous-produit inévitable qui doit être valorisé pour augmenter la compétitivité du procédé. Parmi les différentes possibilités de valorisation, la déshydratation pour donner l’acroléine est le plus prometteur. Ce dernier peut ensuite être converti en acrylonitrile par ammoxidation catalytique. Dans ce projet, les deux réactions – déshydratation et ammoxidation – ont d’abord été étudiés séparément puis ensuite combinés en utilisant un réacteur de type tandem. Pour l’étape de déshydratation, un catalyseur à base de WO3/TiO2 été utilisé. Pour l’ammoxidation, les catalyseurs ont été choisis parmi les oxydes métalliques à base d’antimoine, de fer, de vanadium et de molybdène. Notamment le catalyseur à base de Sb-Fe-O montre des bonnes performances, c’est pourquoi le ratio Sb/Fe été étudié plus en détail. La présence de la phase FeSbO4 est directement corrélée à la sélectivité en acrylonitrile. De plus, on constate une augmentation de la sélectivité en cours de la réaction, ce qui s’explique avec la formation de FeSbO4 in operando. Après l’optimisation des paramètres clefs à l’aide d’un plan d’expérience, les deux réactions ont été combinées. Le rendement maximal obtenu est de 40%. / Due to the depleting reserves of coal, oil and natural gas, we are forced to find renewable alternatives to replace the fossil feedstock for the production of energy and chemical products. An example where renewables are already used to substitute fossil feedstocks is biodiesel. The latter is produced by transesterification of vegetable oils and fats whereby glycerol is formed as a by-product. Due to the large amounts produced, the glycerol needs to be valorized to increase the economical viability of the overall process. One very promising use of glycerol is the dehydration of glycerol into acrolein, which can then be further converted to acrylonitrile. The corresponding ammoxidation is catalyzed by metal oxides.In the present project, both reaction steps were studied separately at first - with focus on the ammoxidation of acrolein - and then connected in a tandem reactor setup finally.For the dehydration of glycerol to acrolein WO3/TiO2 catalysts were used, while oxide catalysts containing antimony, iron, vanadium and molybdenum were developed for the ammoxidation step. Especially, the Sb-Fe-O catalysts were found highly selective and the influence of Sb/Fe ratio was subsequently studied. The presence of a FeSbO4 mixed phase was correlated to a high selectivity to acrylonitrile. Further, an increase in selectivity to acrylonitrile with the reaction time was observed, which was explained by the progressive formation of additional amounts of FeSbO4 over the catalysts during the reaction. After optimizing the key reaction parameter within a design of experiments, both reaction steps were connected in a tandem reactor. A maximum yield in acrylonitrile of 40 % was obtained.

La synthèse du méthylmercaptan CH3SH, précurseur de la méthionine, un acide aminé essentiel, est réalisée industriellement par réaction catalytique entre le méthanol et l’H2S. Cette réaction est rapide et sélective mais l’emploi du méthanol lui-même synthétisé par étapes successives (CH4 + H2O -------> CO/H2 --------> Méthanol) rend attractive une synthèse du méthylmercaptan s’effectuant directement à partir d’un mélange CO/H2 et H2S. Jusqu’à présent, les recherches effectuées sur cette nouvelle voie de synthèse se sont plus particulièrement attachées à l’amélioration des performances catalytiques. Dans ce travail, nous avons cherché, tout en améliorant les performances catalytiques, à déterminer la nature de la phase active. Des catalyseurs de type K-Mo(W) supportés sur alumine, silice et hydroxyapatite ont été utilisés dans ce travail. Différentes teneurs en métaux et différents pré-traitements catalytiques ont été étudiés. La présence simultanée du potassium et du molybdène dans le système catalytique permet d’atteindre des valeurs importantes de conversion du CO et de sélectivité en CH3SH, voire une diminution de la sélectivité en CO2. Dans notre étude, la productivité la plus élevée en méthylmercaptan est obtenue avec un catalyseur K2MoO4/Al2O3 chargé à 17 % en Mo et atteint 211,4 g.h-1.L-1. La caractérisation par XPS a été largement mise à profit et a permis de mettre en évidence sur les catalyseurs la présence d’une nouvelle phase de type KxMS2 (M = Mo or W) pour laquelle les ions potassium sont intercalés entre les feuillets de disulfure de molybdène (tungstène). La quantité de cette phase a été reliée à l’activité catalytique dans la réaction de synthèse du méthylmercaptan à partir du mélange CO/H2/H2S nous permettant de proposer cette phase intercalée comme phase active du catalyseur de thiolation. / Methyl mercaptan (CH3SH), widely used as raw material for the production of organosulfur compounds such as methionine, is commercially synthesized by the reaction of methanol with hydrogen sulfide. Although the formation of CH3SH from CH3OH/H2S route is a fast and selective reaction, a several-steps pathway is required for the synthesis of methanol (CH4 + H2O --------> Syngas --------> Methanol). In this regard, the one-step synthesis of methyl mercaptan from simple starting materials (syngas + hydrogen sulfide) is increasingly attractive for industrial application. So far, the disclosed researches in CH3SH production by this route have been focused in the improvement of catalytic performances. In this work, the improvement of catalytic performances as well as the understanding of the nature of the active phase has been studied. K-Mo(W)-based catalysts supported on alumina, silica and hydroxyapatite were used with this purpose. Different metal loading and catalytic pretreatment were evaluated. The simultaneous presence of Mo and K in the catalytic system allows achieving higher CO conversions and CH3SH selectivity and a decrease in CO2 selectivity. The higher CH3SH productivity was achieved with a high loaded K2MoO4/Al2O3 catalyst (211,4 g.h-1.L-1). With the study and analysis of a series of reference catalysts characterized by XPS, we evidenced the presence of a new phase named KxMS2 (M = Mo or W) in which potassium cations are intercalated between the Mo(W)S2 layers. By correlating the amount of KxMS2 phase with the catalytic performances, we observed that the higher the amount of KxMS2 phase in the catalyst, the higher the CO conversion in the reaction of syngas with hydrogen sulfide to produce CH3SH. Based on these statements we propose that KxMS2 is the active phase acting in the reaction of thiolation of syngas.

Produire l’hydrogène, énergie propre, à partir de ressources renouvelables (biomasse) est un enjeu international d’actualité. Deux types de catalyseurs à base de Ni, CeNiXOY et NiXMg2AlOY, sont étudiés pour la production de H2 à partir de l’éthanol selon deux voies, le reformage vapeur et le reformage oxydant (H2O/EtOH = 3). De nombreuses caractérisations physico-chimiques des catalyseurs permettent de proposer des sites actifs et un mécanisme réactionnel. Les nano-composés CeNiXOY et NiXMg2AlOY sont capables de stocker différentes espèces hydrogène, en particulier des espèces hydrures. Une fois traités in situ sous H2 à température adéquate, ces oxydes mixtes deviennent des nano-oxyhydrures avec la présence d’espèces O2-, de cations en interaction forte et de lacunes anioniques. Ces solides sont des catalyseurs très actifs et efficaces pour la transformation de l’éthanol. Le catalyseur Ni12Mg2AlOY permet d’obtenir un haut rendement en H2 à basse température avec une production de 3 mol molEtOH-1 à 300 °C sans formation de CO. Les catalyseurs Ni3Mg2AlOY et CeNi1OY permettent une forte production de H2 avec 5 mol molEtOH-1 à 650 °C. En présence de O2, les oxyhydrures CeNiXHZOY et NiXMg2AlHZOY (30 mg) sont capables de convertir totalement l’éthanol en produisant 45 mol% de H2 avec une température de four de seulement 60 °C, avec une remarquable stabilité pendant au moins 75 h. Cette réaction auto-entretenue à température ambiante est principalement due à l’énergie dégagée par la réaction exothermique entre les espèces hydrures stockées dans les catalyseurs avec O2 ; les espèces hydrures sont continuellement formées à partir de l’éthanol permettant une réaction soutenue. / The potential benefits of hydrogen economy based on renewable energy sources (biomass) have drawn much attention. Hence studies on H2 production from catalytic transformation of bio-ethanol are very interesting and promising. Two types of Ni-based catalysts, CeNiXOY and NiXMg2AlOY, are studied for H2 production from ethanol through two routes, steam reforming and oxidative steam reforming (H2O/EtOH = 3). Numerous physico-chemical characterizations of the catalysts allow proposing active sites and possible mechanism. The CeNiXOY and NiXMg2AlOY nano-compounds are able to store different hydrogen species in particular hydride species. Once in situ treated in H2 at proper temperature, these mixed oxides become nano-oxyhydrides with the presence of anionic vacancies, O2- species and cations in close interactions which are highly active and efficient catalysts for ethanol steam reforming. The Ni12Mg2AlOY catalyst allows obtaining a low-temperature high-yield H2 production of 3 mol molEtOH-1 at 300 °C without the formation of CO. The Ni3Mg2AlOY and CeNi1OY catalysts are able to produce a very high H2 production of about 5 mol molEtOH-1 at 650 °C. In the presence of O2, CeNiXHZOY and NiXMg2AlHZOY oxyhydrides (30 mg) enable to completely convert ethanol with about 45 mol% H2 production with the oven temperature at only 60 °C, showing remarkable stability for 75 h on stream. This self-sustainable reaction is driven by the energy released from the strong exothermic reaction between the hydride species stored in the catalysts with O2, at the same time hydride species are continuously formed from ethanol to make the reaction sustainable.

Les bioraffineries lignocellulosiques sont en plein essor car elles offrent des alternatives innovantes et économiquement viables aux produits issus des industries pétrolières. La lignine, un des trois constituants majoritaires de la structure cellulaire végétale, pose des problématiques de valorisation en raison de sa structure complexe et diversifiée. Ce biopolymère, constitué de polyphénols, représente pourtant la plus grande ressource naturelle et renouvelable de molécules aromatiques. De nombreuses recherches visent à fonctionnaliser cette lignine pour en améliorer ses propriétés. La très grande majorité des modifications de la lignine présente l’inconvénient de générer des sels et sous-produits en quantités stœchiométriques. Des méthodes de fonctionnalisation plus propres sont donc recherchées. Ce manuscrit de thèse présente de nouvelles méthodes de greffage catalytiques s’appuyant sur l’utilisation de butadiène, monoxyde de carbone et alcool allylique comme réactifs d’alkylation/acylation propres. Ces fonctionnalisations influent significativement sur les propriétés physico-chimiques de la lignine. De plus l’insertion d’insaturations au sein de la lignine ouvre de nouvelles voies de fonctionnalisation et de réticulation pour la synthèse de nouveaux matériaux biosourcés. / Lignocellulosic biorefineries are rapidely developing as they offer alternatives to petroleum industries’s products. Lignin, one of the three main constituent of plant cell, is hardly valorized due to its complex and diversified structure. This biopolymer, made of polyphenols, is the largest natural and renewable resource of aromatic molecules. Many researches aim at functionalizing lignin in order to improve its properties. Most of lignin modifications have the disadvantage of generating salts and by-products in stoichiometric amounts. Cleaner functionalization methods are consequently needed. This thesis manuscript presents new catalytic grafting methods based on the use of butadiene, carbon monoxide and allylic alcohol as clean, efficient and economic alkylation/acylation reagents. These functionalizations have a significant impact on the physicochemical properties of lignin. In addition, the presence of new unsaturations in the material opens the way to further functionalization and crosslinking pathways.