Дисертації з теми "Encre catalytique"
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Belatel, Hafsia. "Contribution à l'étude des propriétés catalytiques des oxydes de molybdène et de tungstène : Corrélation entre structure de surface et activité catalytique." Université Louis Pasteur (Strasbourg) (1971-2008), 2005. https://publication-theses.unistra.fr/public/theses_doctorat/2005/BELATEL_Hafsia_2005.pdf.
Extensive research work and several investigations are still carried out on MoO3 and WO3 as catalysts for hydrodesulfurisation processes of crude oil, selective oxidation of unsaturated compounds and oxidation of hydrocarbons and alcohols. However, these oxide catalysts are replaced by more active and selective Pt based catalysts for hydroisomerization of alkane. Several problems are encountered using these platinum catalysts; it is an expensive metal, rare and sensitive to sulfur. Nevertheless, the presence of a bifunctional behavior for molybenum or tungsten has revived the interest in the catalytic properties of these Mo and W oxides. This dual function is present in carbide, oxicarbide or partially reduced oxide, in a similar manner to the bifunctional Pt deposited on acid alumina ( industrially used for the isomerization of light naphta). In order to get a clear idea about the relationship between the catalytic activity and the electronic structure of the active phase in these systems, we have conducted a systematic research work using the most appropriate characterization techniques such as XPS-UPS, XRD, SEM and BET. Catalytic experiments were performed using bulk MO2, MO3 and MO3/TiO2 (M= Mo, W) for isomerization of n-heptane; isomerization, dehydrogenation and ring opening of cyclic compounds such as methylcyclohexane (MCH) at different experimental conditions. The catalytic behaviors of these Mo and W oxides were compared with those obtained using Pt/Al2O3 and Pt-Ir/ZrO2-SO42- sytems. The overall results clearly indicate that the partially reduced Mo and W oxides behave as bifunctional catalysts in a similar way to Pt deposited on acid supports. This bifunctional phase could be represented as MO2(Hx)ac (M= Mo, W) in which (Hx) represents the Brönsted acid (ac)groups present on the surface. The metallic function is due to the delocalized electrons in MO2
Turtayeva, Zarina. "Genesis of AEMFC (anion exchange membrane fuel cell) at the lab scale : from PEMFC’s inks composition toward fuel cell bench tests in alkaline media." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0285.
Anion exchange membrane fuel cells (AEMFCs) have recently attracted significant attention as low-cost alternative fuel cells to traditional proton exchange membrane fuel cells as a result of the possible use of platinum-group metal-free electrocatalysts. Although AEMFC is a mimic of PEMFC but working in an alkaline medium, water management issues are more severe in AEMFC because ORR in alkaline media requires water, while at the same time water is produced at the anode side. To better understand water management in this type of fuel cell, it is necessary first to develop and gain experience with this kind of fuel cell on the laboratory scale. Since no ready-to-use materials are available at the beginning of the project, the necessity of fabricating homemade MEAs from commercially available materials becomes a reality that we must face. As MEA fabrication is a new topic to LEMTA's researchers, this is why this thesis was divided into two parts: one part dedicated to the formulation, preparation, and optimization of MEAs for PEMFC through physico-chemical and electrochemical characterizations; another part dedicated to the development of AEMFC. The results indicated that ink deposition, composition, and preparation systematically change the electrode structure and thus affect fuel cells performance. Furthermore, the study provides information on the AEMFC procedures and methods. Here, we would like to share our know-how with newcomers in the field of preparation of MEA in ion exchange membrane fuel cells
PAYET, DOMINIQUE. "Interactions entre l'adn et des derives du platine (ii) : activite catalytique de la double helice d'adn." Orléans, 1994. http://www.theses.fr/1994ORLE2029.
Issa, May. "Etude théorique et expérimentale de l'oxydation catalytique du noir de carbone : Influence du contact entre solides." Mulhouse, 2008. https://www.learning-center.uha.fr/opac/resource/etude-theorique-et-experimentale-de-loxydation-catalytique-du-noir-de-carbone-influence-du-contact-e/BUS4168757.
Stringent standards have been imposed to reduce the emisions of soot particulates known by their danger for human health and environnment. DPF (Diesel particulate filter), enables to collect soot particulates in the exhaust gas, should be regernerated periodically by soot combustion. This regeneration could be active or passive. Passive regeneration uses catalysts in the filter to promote soot oxidation at lower temperatures (400-500°C). Therefore, this investigation was dedicated to the effect of contact between carbon black (model of diesel soot) and catalyst (cerium oxide) and its influence on carbon black oxidation in the presence of oxygen. A correlation between the morphology of mixtures of carbon black and cerium oxide and the reactivity of carbon black was established. Mathematical models (1D and 3D) were developped. These models predict soot oxidation taking into account different parameters based on experimental results. In partiuclar, the three dimensionnai model represents the studied mixtures considering that catalyst is composed of agregates with different sizes. These agregates, distributed randomly in the system, are composed of isometric elementary volumes of 200 nm of length. This representation enables to estimate the effect of the contact between carbon black and catalyst on carbon black oxidation. The model determines the catalytic neighberhood of each elementary volume of carbon black. A good agreement was obtained between experimental results and calculated ones by the model. Indeed, a three dimensionnai model based on geometrical representation of DPF was developped to get a better insight on the phenomena occuring during the regeneration process
Garreau, François. "Étude des relations entre structures et activités catalytiques dans le système nickel-molybdène-soufre /." Paris : Technip, 1987. http://catalogue.bnf.fr/ark:/12148/cb349659890.
Imberdis, Arnaud. "Réactions d’interconversion catalytiques entre composés C1 : CO2, CO, acide formique, méthanol, méthane et dérivés." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS306/document.
Our society has grown considerably thanks to the use of fossil resources. The use of these resources, in the field of energy or the chemical industry, leads to a disruption of the natural carbon cycle caused by the accumulation of an anthropogenic CO2 in the atmosphere. To overcome this issue, one of the conceivable solutions is to gradually abandon fossil hydrocarbons in favor of renewable carbon resources such as CO₂ for the storage of renewable energies and / or as a source of chemical products. The first building blocks obtained from CO2 are one carbon atom containing molecules, known as C1 compounds. It includes methane (CH4), carbon monoxide (CO), methanol (CH3OH), formic acid (HCOOH). These reactions are limited by their practicality, their yield or by their selectivity. Therefore, they are not an ideal solution to the initial problem. In this context, this doctoral work has explored alternative ways of interconverting these compounds to offer CO2 recovery pathways. In the first place, the use of HCOOH was proposed as a CO vector. This topic is born of the growing interest for the organic chemistry sector to obtain liquid or solid sources of CO. In a second step, a new disproportionation strategy was developed to access CH3OH from HCOOH derivatives, the silicon formates. These reagents allow to avoid the thermodynamic limitation related to the disproportionation of HCOOH. The control of the silylated by-products recycling enabled the success of this transformation. A new CH4 production route was also developed from CH3OH using HCOOH as a reducing agent. Finally, the knowledge acquired on CO2 activation and reactivity enabled a transposition by analogy to other iso-electronic molecules, including carbodiimides in order to form the isoureas under organocatalytic conditions
Durin, Guillaume. "Mécanisme catalytique de la protochlorophyllide oxydoréductase : étude du couplage entre activité fonctionnelle et dynamique de la protéine." Phd thesis, Université Joseph Fourier (Grenoble), 2005. http://tel.archives-ouvertes.fr/tel-00011429.
Nous avons d'abord mis en évidence que la longueur d'onde et l'intensité de la source de lumière choisie pour déclencher la réaction à basse température influait directement sur le mécanisme réactionnel suivi, révélant par la même l'existence d'une « branche morte » de la réaction, dont le produit n'est pas la chlorophyllide.
Nous avons ensuite suivi par spectroscopie d'absorption et de fluorescence le déroulement des deux mécanismes réactionnels : la branche physiologique et la « branche morte ». Ces études ont été réalisées entre 100 et 293 K dans des solutions de viscosités différentes, afin de faire varier la température de transition vitreuse (Tg) du solvant. En suivant en parallèle Tg et la formation des différents états intermédiaires, nous avons montré que les étapes initiales du premier mécanisme étaient couplées avec cette transition alors qu'elles en étaient indépendantes pour le second. Ces travaux ont permis de mettre en évidence l'existence de différents types de mouvements régissant l'activité fonctionnelle de la protéine, certains couplés avec le solvant (« bulk solvent ») et d'autres de type harmonique, indépendants du solvant.
Haddoud, Farah. "Utilisation du peroxyde d'hydrogène pour l'oxydation de déchets industriels à une température comprise entre 100 et 150oC : étude de la dégradation des acides carboxyliques légers." Toulouse, INSA, 1989. http://www.theses.fr/1989ISAT0025.
Cheval, Muriel. "Correlations entre les proprietes catalytiques et les etats de surface de tungstene : metal, oxyde, carbure, oxycarbures." Université Louis Pasteur (Strasbourg) (1971-2008), 1992. http://www.theses.fr/1992STR13141.
Boulard, Séverine. "Couplage entre transport et adsorption d'hydrocarbures dans des matériaux catalytiques microporeux destinés à la réduction des NOx." Mulhouse, 2005. http://www.theses.fr/2005MULH0789.
Severe European standards require car manufacturers to think about efficient post-combustion systems. Zeolites,microporous materials,have aroused a large interest in this domain. To improve the specifications of such systems,it is necessary to have a better knowledge of the reaction mechanisms. This work has been performed in this point of view. Inverse gas chromatography technique has been used for the determination of the adsorption and transport properties of hydrocarbons within these catalytic materials. From the chromatographic response curve,we can determine relevant information,such as Henry's constants and diffusion coefficients. A qualitative study has been realised to investigate the accessibility of hydrocarbons to the pores of the materials. Thermodynamic and diffusional parameters have been determined. A simulation modelling of the chromatographic response curve has been adjusted,allowing better estimations of the diffusion coefficients of the probes
Lorcy, Nolwenn. "Réactions de couplage entre un composé organomagnésien et un phosphate d'énol en présence d'une quantité catalytique de sel de fer." Cergy-Pontoise, 2001. http://biblioweb.u-cergy.fr/theses/01CERG0125.pdf.
Many natural products which are biologically actives are made of conjugated or not polyunsaturated systems such as pheromones, leucotrienes Usually, these polyunsaturated systems are obtained using Wittig reaction, partial hydrogenation of triple bond or substitution reaction of vinylics compounds with Grignard reagents in the presence of a transition metal. That work show a new method to form Csp2-C bonds by cross-coupling between Grignard reagent and enol phosphate catalyzed by iron salt. Iron salts are particularly attractives because they are easily prepared and can be used as catalyst. A great interest in this reaction is that enol phosphate permits to easily access to a large diversity of original products from corresponding carbonyls compounds. As a matter of fact, many kinds of enol phosphates are presented in this work. They derived from cyclicals, acyclicals, symmetrics or not, aromatics and benzylics ketones or they derived from -ketoesters or aldehydes. Enol phosphates are stables and less cheap than corresponding triflates which are often used in this cross-coupling reaction. This procedure has a large scope of application. Various enol phosphates have been converted to di-, tri- and tetra-substituted olefins compounds in satisfactory yields. Dienol phosphates, derived from , -unsaturated aldehydes, lead to conjugated terminal or not dienes. The best results are obtained with alkylmagnesium halide. On the one hand cross-coupling products are obtained in good yields and with retention configuration using E enol phosphates. On the other hand, enol phosphates with Z configuration are less reactives, they sometimes can isomerised. This cross-coupling reaction is chemoselective. Thus various reactive compounds such as chlore, nitrile, ketone or ester group are tolerated in spite of there very high reactivity towards Grignard reagents. This study develops a new strategy to form cross-coupling products by the alkylation reaction catalyzed by copper salt followed by the alcenylation reaction catalysed by iron salt, in a same reactor
Abel, Mathieu. "Etude STM de dépôts de Pd / M(110) (M=Ni, Cu, Au) : relation entre la structuration superficielle et l'activité catalytique." Ecully, Ecole centrale de Lyon, 2001. http://bibli.ec-lyon.fr/exl-doc/TH_T1871_mabel.pdf.
Lhouty, Mohammed Hassane. "Etude de l'activité catalytique basique de l'hydrotalcite : application à la condensation aldolique entre le benzaldéhyde et l'acétone (Réaction de Claisen-Schmidt)." Montpellier 2, 1993. http://www.theses.fr/1993MON20118.
Jalowiecki-Duhamel, Louise. "Relation entre les orientations de réactions catalytiques et la structure superficielle de sites dans les oxydes et sulfures métalliques." Lille 1, 1989. http://www.theses.fr/1989LIL10023.
Giordano, Laurent. "Nouvelles réactions catalytiques entre les Bicycles [2. 2. 1] insaturés et les alcynes induites par le palladium et le ruthenium." Aix-Marseille 3, 2002. http://www.theses.fr/2002AIX30006.
In our research work, we have been involved in the development of new catalytic reactions of unsaturated bicyclic[2. 2. 1] compounds and alkynes. An efficient palladium catalysed addition of terminal alkynes across one double bond of norbornadiene resulting in the selective formation of exo-5-alkynyl-bicyclo[2. 2. 1] hept-2-enes is reported. The reaction show general applicability to various functionalized alkynes and bicyclo[2. 2. 1]hepta-2,5-dienes. Mechanistic insights into these reaction are also provided on the basis of labelling experiments. A new synthesis of 8,9-disubstituted deltacyclenes via a [2+2+2] cycloaddition of norbornadiene with disubstituted alkynes has been achieved with ruthenium catalyst systems. The reaction is applicable to various disubstituted alkynes and 7-substituted norbornadienes. The Homo-Diels Alder Reaction becomes more efficient when the C7-substituent is an aryl or alkyl group. Finally, an efficient catalyst system combining CpRuCl(PPh3)2 and MeI allow the [2+2] cycloaddition of norbornadiene or norbornene with various disubstituted alkynes providing functionalized tricyclic compounds. We have shown that the activation of CpRuCl(PPh3)2 with methyl iodide generates in situ CpRuI(PPh3)2 as the key catalyst
Elayadi, Houda. "Comparaison physico-chimique et sites catalytiques entre les solides Au/CeO2 préparés par deux méthodes différentes : déposition-précipitation et imprégnation." Littoral, 2010. http://www.theses.fr/2010DUNK0269.
Two 4%Au/CeO2 catalysts have been prepared by two different methods : deposition-precipitation (DP) and impregnation (Imp). From the XRD, SEM and TEM study, nanoparticles of gold have been evidenced in the DP catalyst and agglomerates nearby nanoparticles in the Imp solid. Compared to the Imp solid, the DP catalyst showed a better catalytic activity in the CO oxidation reaction, the total oxidation of propene and the combustion of carbon black (soots). This difference in the activity is related to the presence of well-dispersed gold nanoparticles on the DP solid surface and a significant quantity of Aun+ located nearby the metallic gold and the O2- ions of the ceria lattice. The weak activity of the Imp catalyst is correlated to the presence on the surface of gold agglomerates and an important amount of chloride ions. These latter species are known as inhibitor in calatysis. In order to elucidate the redox properties of both DP and Imp catalysts, the solids have been degassed and treated under vacuum at 400°C for 1h before the absorption of air. Therefore, the two catalysts have been studied with the EPR technique. Two signals completely different have been evidenced : the first one with g- < g// on DP and the other one, denoted M, with g- > g// on the Imp catalyst. The DP signal has been attributed to O2- species whereas, the attribution of M signal has needed of more detailed study. In fact, the adsorption of air on x%Au/CeO2 (Imp) solids, where 0 <(or egal) x <(or egal) 4, has shown using the EPR technique, the appearance of a new P signal nearby of the M signal for Au contents less than x = 2. 5. From EPR results obtained after absorption, on x%Au/CeO2 (Imp) solids, O2, N2, O2+N2 or air, O2 before N2 ; N2 before O2, NO, N2O and NO2, the P signal has been attributed to O2- , NO2 2- or NO3 2- and M signal M to NO, O- or N2O-. The Nox formed can be considered as intermediate or final products. From these results mechanisms corresponding to all the formed products have been proposed
Forge, Vincent. "Interactions entre les sites de transport et le site catalytique de l'atpase-ca du reticulum sarcoplasmique revelees par la liaison du calcium et des protons." Paris 6, 1994. http://www.theses.fr/1994PA066123.
Lacaze, Jean-François. "Relations entre l'acidité de zéolithes ZSM-5 substituées isomorphiquement par Al, Fe, Ga, B et leurs propriétés catalytiques dans les réactions de condensation." Pau, 1998. http://www.theses.fr/1998PAUU3010.
Azgui, Samira. "Comparaison des performances catalytiques entre un réacteur à lit fixe et un réacteur à lit fluidisé : application à la réduction des oxydes d'azote." Compiègne, 1997. http://www.theses.fr/1997COMP1036.
Skaf, Mira. "Comparaison physico-chimique et des [sic] activités catalytiques dans les réactions d'oxydation entre deux séries de catalyseurs Ag/CeO₂ préparés par imprégnation et dépôt-précipitation." Phd thesis, Université du Littoral Côte d'Opale, 2013. http://tel.archives-ouvertes.fr/tel-00983419.
Onfroy, Thomas. "Oxydes de tungstène et de niobium supportés sur zircone et dioxyde de titane : corrélations entre le caractère acide, la nature des espèces superficielles et l'activité catalytique en déshydratation de l'isopropanol." Caen, 2004. http://www.theses.fr/2004CAEN2038.
RIGUET, ERIC. "Reaction de couplage aryl-aryle, entre un organometallique et un bromure ou un chlorure aromatique, catalysee par un complexe du palladium ou du nickel. Cyclisation stereoselective utilisant un nouveau systeme catalytique mn/cu." Paris 6, 1997. http://www.theses.fr/1997PA066715.
Faucher, Florian. "Etude par spectroscopie infrarouge in situ et operando des relations entre les propriétés des sites d'adsorption de solides hybrides organiques-inorganiques (MOFs) et leurs propriétés catalytiques pour des réactions modèles." Caen, 2016. http://www.theses.fr/2016CAEN2039.
This work reports the characterization by infrared spectroscopy of an iso-structural family of MOF (Metal Organic Framework) named MIL-100 (X) (MIL : Matériau de l’Institut Lavoisier) with X = Al3+, Fe3+, and Cr3+. We demonstrated the decisive influence of the synthesis conditions on the reductibility of the Fe3+ sites and on the final acid and catalytic properties of the material. In particular, the F-free MIL-100(Fe) material exhibits not only Lewis acid sites, but also a high amount of additional catalytic active species acting as Brønsted acid sites. The third part, devoted to the study of MIL-100(Cr), shows the existence of a high amount of acid-base pairs having a strong basic character in accordance with a high selectivity for allylic alcohols. The last part demonstrates the high activity of the MIL-100(Al) material, due to the high Lewis acidity of the Al3+CUS sites. This work demonstrates the important influence of impurities in the acid and catalytic properties of these materials, which show that only MOFs with a high purity can be considered as model compounds. This work also opens the possibility to obtain MOFs with an additional high Brønsted acidity without altering the framework
Srour, Toni. "Optimisation de l'interface entre la couche catalytique anodique et la couche de transport dans un électrolyseur PEM : effet d'un dépôt de métal noble et de la contrainte de serrage sur les performances et la durabilité." Electronic Thesis or Diss., Université de Lorraine, 2023. https://docnum.univ-lorraine.fr/ulprive/DDOC_T_2023_0283_SROUR.pdf.
From an economic perspective, the widespread adoption of PEMWE electrolyzers in mass markets depends on reducing cell manufacturing costs (currently over €1000/kW) and improving their lifespan. Additionally, due to the variable nature of renewable energy sources, efficient and rapid power fluctuations are vital for large-scale development. Industry aims to cut PEM electrolyzer CAPEX by increasing active surface area and current density. However, this creates operational inconsistencies, leading to hotspots and limiting durability. In our Super Stack project, we studied the sensitivity of PEM electrolysis cells to non-uniform clamping forces, common in large-scale systems. Results show a sensitivity of approximately 3 mΩ.cm².MPa⁻¹ for materials used. Noble metal depositions like iridium and platinum reduce electrical contact resistance by over 30%, boosting efficiency by 6%. They also lower thermal resistance, reducing membrane temperature at high current densities. For example, at 70°C and 5A/cm², membrane temperature drops from around 105°C to 75°C with a 10nm iridium deposition on the anodic catalytic layer-facing PTL. This deposition proves crucial in mitigating membrane degradation, especially in low clamping force areas. Accelerated Stress Tests confirm the durability benefits of depositions, particularly iridium, making them economically viable
El, Hajj Ahmad. "Nouveaux concepts d’élaboration de la pyrazolidine par la méthode Raschig et par voie indirecte, en transitant par la 1 et 2-pyrazoline, suivie d’une hydrogénation catalytique : synthèses et modélisations cinétiques, équilibres entre phases et schémas de procédés." Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10354.
This work, conducted as part of a research agreement with the Company ISOCHEM, aims to develop a new synthesis of pyrazolidine by the raschig method and by indirect way via 1 and 2-pyrazoline followed by catalytic hydrogenation. This hydrazine is very important, because of its many applications in the pharmaceutical and cosmetic industries. This thesis was funded by the National Center for Scientific Research as part of a doctoral fellowship engineer / PED. The first part is devoted to the study of the direct Raschig process resulting from the action of sodium hypochlorite in an excess of amine. The definition of the process involved the determination of the kinetic and reaction mechanisms to determine yields, residence time and to simulate numerically the overall operations of synthesis. The extraction conditions were established by exploiting the peculiarities of the phase equilibria in order to developed the flow-sheet. The second part relates to the indirect way. It is based on the synthesis of the 1 pyrazoline by double dehydrohalogenation of N,N-dichloro-1,3-diaminopropane. The pyrazolidine is then obtained by catalytic hydrogenation of the azo group. A global model for developing the pyrazolidine was established which allowed us to determine the optimum conditions and to identify segments syntheses and extractions as well as various unit operations of the process and the mass and energy balances
Yianni, Yiannoula. "Aspects cinétiques des deux étapes de la réaction équilibrée entre les amino-acides (ou les céto-acides) et la forme aldéhydique (ou amine) du phosphate de la vitamine B6 : influence de la structure et de l'acidité, rôle catalytique des espèces complexées par les ions aluminium." Grenoble 1, 1988. http://www.theses.fr/1988GRE10041.
Yianni, Yiannoula. "Aspects cinétiques des deux étapes de la réaction équilibrée entre les amino-acides (ou les ceto-acides) et la forme aldéhydique (ou aminé) du phosphate de la vitamine B6 influence de la structure et de l'acidité : rôle catalytique des espèces compléxées par les ions aluminium /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37619300k.
FLORENTZ, EGELE CATHERINE. "L'extremite 3'oh aminoacyable du rna du virus de la mosaique jaune du navet : relations entre structure et fonctions." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13181.