Dissertationen zum Thema „Support de catalyseurs“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-50 Dissertationen für die Forschung zum Thema "Support de catalyseurs" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Dissertationen für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
Harle, Virginie. „Nouveaux supports TiO2-Al2O3 pour les catalyseurs d'hydrotraitement : de la synthèse à la compréhension de l'effet de support“. Lyon 1, 1994. http://www.theses.fr/1994LYO10193.
El, Azhar Mohammed. „Influence du support sur les propriétés catalytiques du platine“. Lyon 1, 1989. http://www.theses.fr/1989LYO10055.
Gogolieva, Ganna. „Catalyseurs greffés sur support et libérés sous stimulus externe“. Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/11916/1/gogolieva.pdf.
Ninh, Thi Kim Thoa. „Une nouvelle approche dans l’évaluation de l’effet de support des catalyseurs d’hydrodésulfuration“. Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10028/document.
The main objective of this work was to evaluate the support and the promoting effect on the catalytic properties of HDS catalysts. In order to obtain appropriate catalytic systems, we applied the “acac method” which consists to add the promoter as an acetylacetonate complex (of Co, Ni or Fe) onto the supported molybdenum sulfide (on γ-Al2O3, SiO2, TiO2 and ZrO2). The various solids obtained were characterized by TEM, IR(CO) and XPS in particular to quantify the active phases, and then they have been tested in the HDS reactions of thiophene and 4,6-DMDBT. The catalytic activity has been correlated to the characterization datas by a new approach which consists in calculating the apparent catalytic activity by NiMoS or CoMoS site. This approach showed that the quality of the active sites is the best on SiO2 and comparable on γ-Al2O3, TiO2 and ZrO2. Moreover, this “acac method” allowed us to study supported CoNiMoS catalysts synthesized by adding Co and Ni either simultaneously or successively to MoS2. This study represents an important experimental contribution which allow to discuss the hypothesis developped in theoretical studies about the different affinities of Co and Ni for the S-edge and Mo-edge on γ-Al2O3 and TiO2
Arii, Sandrine. „Oxydation du CO sur des catalyseurs supportés à base d'or produits par vaporisation laser : effet de support et d'alliage“. Lyon 1, 2003. http://www.theses.fr/2003LYO10143.
Wojcieszak, Robert. „Catalyseurs de nickel Supportés Préparés par la Méthode de l'Hydrazine Aqueuse. Propriétés Hydrogénantes et Stockage d'Hydrogène : Effet du Support. Effet de l'Ajout d'Argent“. Nancy 1, 2006. http://docnum.univ-lorraine.fr/public/SCD_T_2006_0023_WOJCIESZAK.pdf.
We have studied Ni or NiAg nanoparticles obtained by the reduction of nickel salts (acetate or nitrate) by hydrazine and deposited by simple or EDTA-double impregnation on various supports (g-Al2O3, amorphous or crystallized SiO2, Nb2O5, CeO2 and carbon). Prepared catalysts were characterized by different methods (XRD, XPS, low temperature adsorption and desorption of N2, FTIR and FTIR-Pyridine, TEM, STEM, EDS, H2-TPR, H2-adsorption, H2-TPD, isopropanol decomposition) and tested in the gas phase hydrogenation of benzene or as carbon materials in the hydrogen storage at room temperature and high pressure. The catalysts prepared exhibited better dispersion and activity than classical catalysts. TOF's of NiAg/SiO2 or Ni/carbon catalysts were similar to Pt catalysts in benzene hydrogenation. Differences in support acidity or preparation method and presence of Ag as metal additive play a crucial role in the chemical reduction of Ni by hydrazine and in the final properties of the materials. Ni/carbon catalysts could store significant amounts of hydrogen at room temperature and high pressure (0. 53%/30 bars), probably through the hydrogen spillover effect
Ninh, Thi Kim Thoa. „Une nouvelle approche dans l'évaluation de l'effet de support des catalyseurs d'hydrodésulfuration“. Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00843895.
Guevara, Lara Alfredo. „Effets de support et de solvant dans l'évaluation de l'activité des catalyseurs d'hydrotraitement nickel-molybdène supportés sur oxydes mixtes“. Lyon 1, 2003. http://www.theses.fr/2003LYO10017.
Martinez, Hugo. „Influence des proprietes acido-basiques du couple support-reactif lors du cokage des catalyseurs metalliques supportes“. Poitiers, 1988. http://www.theses.fr/1988POIT2320.
Tountian, Dihourahouni. „Hydrogénation électrocatalytique : effet de la conductivité et de la fonctionnalisation du support des nanoagrégats métalliques, utilisation du dioxyde d’étain comme support“. Strasbourg, 2009. https://publication-theses.unistra.fr/public/theses_doctorat/2009/TOUNTIAN_Dihourahouni_2009.pdf.
The electrocatalytic hydrogenation (ECH) is a heterogeneous catalysis in which the nature of the electrode material is of high importance. New composites electrocatalysts (conductor and non-conductor) of palladium nanoparticles supported on tin dioxide were prepared by three different methods for phenol and cyclohexanone ECH. The results presented in this thesis show that the conductivity of the electrode material is an important factor in the ECH process. When the support material is conductor, there is an effective production of chemisorbed hydrogen by simultaneous polarization of all the metallic nanoparticles which contributes to greater efficiency of hydrogenation. Also, the ECH is pH dependent and this dependency is reflected by the variation in molecular species in solution and their adsorption on the electrode. The in situ functionalization of electrode materials by carboxylic acids with different side chains allowed controlling the adsorption step (rate-determining step) and thus modulating the efficiency of hydrogenation. This result opens up promising prospects for selective and enantioselective hydrogenation
Tountian, Dihourahouni Poillerat Gérard. „Hydrogénation électrocatalytique effet de la conductivité et de la fonctionnalisation du support des nanoagrégats métalliques, utilisation du dioxyde d'étain comme support /“. Strasbourg : Université de Strasbourg, 2009. http://eprints-scd-ulp.u-strasbg.fr:8080/00001110.
Frémon, Benoit. „Nouvelle approche de la préparation des catalyseurs d'hydrotraitement par fonctionnalisation du support“. Lille 1, 2007. http://www.theses.fr/2007LIL10156.
Mouaddib, Najat. „Synthèse des alcools supérieurs à partir de CO + H2 sur des catalyseurs CuCo supportés : influence du support“. Lyon 1, 1989. http://www.theses.fr/1989LYO10058.
Prévost, Marina. „Etude par spectroscopies XPS et ISS d'hétéropolyoxométalates massiques et supportés, catalyseurs d'oxydation sélective : Interaction support-phase déposée“. Lille 1, 1989. http://www.theses.fr/1989LIL10118.
Barthe, Laurie. „Synthèse et dépôt de nanoparticules métalliques dans un support poreux par imprégnation en voie sèche dans un lit fluidisé : élaboration de catalyseurs supportés“. Toulouse, INPT, 2007. https://hal.science/tel-04595494.
The present work concerns the synthesis and deposit of metallic nanoparticles in a porous support using a dry impregnation method in a fluidized bed. The principle of this technique consists in spraying a solution containing the metal source into a hot fluidized bed of porous particles. Two types of precursors have been used: a metal salt solution and a colloidal suspension. The experimental study deals with the process parameters. In addition, the porous support physicochemical properties influence on the metallic elements such as dispersion in the matrix and size repartition is also presented. It is found that the operation effectiveness is 100%. The deposit location can be controlled depending on the operating conditions thanks to a new adimensional number, the Impregnation Module. Thus, the deposit can be performed at the support particle surface or inside the grain during the spraying of metallic salts or colloidal suspensions on a support sized between 100 μm and few millimetres. The calcination operating conditions have an effect, more or less important depending on the support nature, in the metallic element size being the key parameter the heating rate. Support porosity also plays an important rôle because the matrix pore diameter controls the nanoparticles cluster maximal size. Finally, the composite materials obtained present good activity and selectivity in the hydrogenation reaction of aromatic compounds and carbon nanotubes synthesis
Ionescu, Andrei-Radu. „Modélisation des catalyseurs d'hydrodésulfuration : étude théorique des interactions entre le support et la phase active“. Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11023.
Wojcieszak, Robert Bettahar Mohammed El-Miloud. „Catalyseurs de nickel Supportés Préparés par la Méthode de l'Hydrazine Aqueuse. Propriétés Hydrogénantes et Stockage d'Hydrogène Effet du Support. Effet de l'Ajout d'Argent /“. [S.l.] : [s.n.], 2006. http://www.scd.uhp-nancy.fr/docnum/SCD_T_2006_0023_WOJCIESZAK.pdf.
Bui, Van Ngoc. „Catalyseurs cobalt-molybdène pour l'hydrodésoxygénation du guaïacol : effet de support et effet de promotion“. Lyon 1, 2008. http://www.theses.fr/2008LYO10228.
PETER, ANDRE. „Influence du support alumine sur l'activite hydrodesulfurante de catalyseurs au molybdene et cobalt molybdene“. Université Louis Pasteur (Strasbourg) (1971-2008), 1991. http://www.theses.fr/1991STR13228.
Ma, Jiwei. „Développement de catalyseurs cathodiques nanométriques sélectifs à l'environnement organique pour leur utilisation dans une pile microfluidique“. Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2274/document.
Fuel cells without polymeric membrane such as the microfluidic fuel cells (MFFC) possess very interesting perspectives for low-power energy applications. The study aimed at pursuing the development of nanometric cathodic catalysts and to study their activity, stability and tolerance in a microfluidic system. In the present thesis, the activity, stability and tolerance of Pt-based nanoparticle electrocatalysts were investigated. The effect of the support materials and the influence of surface modification by a second element including 3d transition metal (titanium) and chalcogenide (selenium) were studied. The separation and reduction of the complexity of the interaction between nanoparticles-support and nanoparticles modification by a second element enables to achieve a clear relationship of the structure-activity-stability-tolerance of the supported fuel-cell electrocatalysts. The present experimental results from the effects of the support materials and of the modification of Pt by a second element led to improve activity, stability and tolerance. The developed approach and acquired knowledge about surface property correlation can be further generalized and used in the design of advanced selective electrocatalysts. Furthermore, the synthesized electrocatalysts were used as cathode in an organic microfluidic fuel cell
Mauchausse, Christine. „Influence du support sur les propriétés catalytiques et morphologiques de catalyseurs à base de sulfure de molybdène, actifs en hydrogénation du CO“. Lyon 1, 1988. http://www.theses.fr/1988LYO19017.
Debono, Nathalie. „Catalyseurs homogènes supportés et mixtes à base de bisoxazolines : applications à la réduction énantiosélective“. Lyon 1, 2004. http://www.theses.fr/2004LYO10161.
Hadj, Aïssa Mohammed. „Influence de la vapeur d'eau sur le cokage des catalyseurs métalliques“. Poitiers, 1987. http://www.theses.fr/1987POIT2296.
PENGUILLY, VANESSA DE. „Etude de catalyseurs bimetalliques pt - w supportes sur alumine : vers un suivi moleculaire des interactions metal / support au cours des etapes de la preparation d'un catalyseur a 3 composantes“. Paris 6, 1998. http://www.theses.fr/1998PA066587.
Corbos, Elena Cristina. „Effets du support et des ajouts sur les propriétés de stockage des NOx de catalyseurs à base de baryum : sensibilité au souffre“. Poitiers, 2007. http://www.theses.fr/2007POIT2297.
The aim of this work is to study the influence of various parameters on the NOx storage properties and sulfur resistance of Ba based NOx trap catalysts. In the first part, we studied the influence of the support oxide (Al2O3, SiO2, Al2O3-5,5SiO2 and Ce0,7Zr0,3O2) and the Ba loading. These parameters influence Pt and Ba dispersion and thus the Pt-Ba proximity, the basicity of the catalysts and the NOx storage. The addition of CO2 and H2O in the inlet gas has an inhibiting effect on the NOx storage capacity due to (i) CO2/NOx competition for the storage sites - increasing with the basicity and the temperature and (ii) a decrease of NO oxidation activity and NOx storage on the support sites (H2O). Compared to Al, CeZr support oxide leads to a decrease of about 100°C of bulk BaSO4 reduction temperature, thus leading to a better sulfur elimination during the regeneration of the sulfated catalysts. In the second part we investigated the influence of the catalysts preparation, the activation treatment and the effect of additives to Ba (Fe, Mn and Ce) on the properties of Pt/Ba/Al catalysts. The activation of the catalysts under N2 before ageing led to an increase of Pt and Ba dispersion and thus to an increase of the NOx storage. The addition of Mn and Ce to Pt/Ba/Al catalysts contributes to improve the storage properties. Adding Mn and Fe to a catalyst with a low barium content leads to an increase of the sulfur resistance regarding NOx storage. Finally, even if the sulfur regeneration of the modified catalysts is less efficient than for non modified ones, the formers are more actives regarding NOx storage after regeneration
DEMRI, HARIK OJAMILA, und J. P. HINDERMANN. „Etude des interactions metal-support et metal-promoteur sur des catalyseurs a base de rhodium“. Université Louis Pasteur (Strasbourg) (1971-2008), 1992. http://www.theses.fr/1992STR13101.
Dumeignil, Franck. „Améliorations de catalyseurs d'hydrodésulfuration Co-Mo-alumine et modification du support par ajout de bore“. Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-261.pdf.
Dorion, Catherine. „Étude de catalyseurs déposés pour réacteur photocatalytique de traitement des eaux“. Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_DORION_C.pdf.
Traversaz, Olivier. „Etude des interactions relatives metal-metal et metal-support mises en jeu lors de la preparation de catalyseurs bimetalliques supportes“. Paris 6, 1992. http://www.theses.fr/1992PA066621.
Gerez, Thierry. „Développement de catalyseurs pour le transfert d'hydrogène : application à des molécules biosourcées“. Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10246/document.
In this study, we evaluated the compatibility of polyfunctional alcohols with catalytic aerobic oxidation systems. Geraniol dehydrogenation was carried out in mild conditions (t-BuOH / water mixture as solvent, 40°C) in the presence of Pt / C (promoted with Bi to avoid leaching). These catalysts are efficients for the oxidation of 8-Chloro-1-Octanol into corresponding acid at 90°C. However, other reactants were not selectively transformed into aldehyds or acids because of their oxygen sensivity (alcool-A) or their particular reactivity toward cyclization products (5-Chloro-1-Pentanol). In parallel, H transfer dehydrogenation was developed in anaerobic conditions. Geraniol was choosen as a model molecule since it can be selectively dehydrogenated or isomerizd (a reducible function on the substrate is hydrogenated when alcohol function is dehydrogenated). Some noble metals were evaluated for these reactions (Pd in the presence of alkene as H acceptor or Ag for acceptorless dehydrogenation), but performances and selectivities are quite low. Copper catalysts showed better results, and a lot of supports were evaluated. Selectivity toward dehydrogenation product (citral) is not total when styrene is used as hydrogen acceptor, but the use of another H acceptor (confidential) in the presence of copper supported on modified hydrotalcite catalyst allows selective dehydrogenation of geraniol without isomerization intro citronellal. Without H acceptor, this catalyst leads to selective isomerization of secondary allylic alcohols into saturated ketones (90 % selectivity)
Kribii, Abdelaziz. „Préparation, caractérisation et désactivation de catalyseurs à base de cuivre“. Poitiers, 1987. http://www.theses.fr/1987POIT2009.
Akhachane, Abdelkrim. „Sensibilité au dépôt de carbone de catalyseurs à base de platine et de palladium déposés sur support peu acide“. Poitiers, 1994. http://www.theses.fr/1994POIT2295.
Methivier, Christophe. „Les carbure et nitrure de silicium utilisés comme support de catalyseurs au palladium : application à l'oxydation totale du méthane“. Lyon 1, 1997. http://www.theses.fr/1997LYO10267.
Rosenberg, Elisabeth. „Étude par microscopie électronique et spectroscopie exafs de la structure massique et superficielle de petites particules métalliques et des phénomènes d'épitaxie métal-support sur des catalyseurs monométalliques supportés /“. Rueil-Malmaison : Paris : Institut français du pétrole ; diffusion Technip, 1985. http://catalogue.bnf.fr/ark:/12148/cb348368415.
Martinez, Hugo. „Influence des propriétés acido-basiques du couple support-réactif lors du cokage des catalyseurs métalliques supportés“. Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37615817q.
Bara, Cédric. „Catalyseurs d'hydrotraitement à base de Mo supporté sur alumine : genèse de la phase active et effet de support par une approche science des surfaces“. Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066332/document.
The objective of this work was to develop a surface science approach to study the support effect on the genesis and structure of the active phase (molybdenum sulfide) on alumina supported Mo based hydrotreating catalysts supported on alumina which are used for petroleum refining. The originality of the work lies in the aqueous phase metal precursor deposition (molybdates) according to two synthetic routes (equilibrium adsorption and impregnation) on α alumina single crystals (γ alumina surrogate) with 4 different orientations (C (0001), R "(1" ¯("1" ) "02)" , A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" ). The combination of several physico-chemical characterization techniques (XPS, AFM, TEM, EXAFS) has shown that the surface structure of each crystal orientation governs the strength of metal/support interaction in the oxide state and thus the sulfidation degree and size of the sulfide active phase nanoparticles. This sulfide phase has been associated to a type I (strong metal/support interactions, lower sulfurability) for the R "(1" ¯("1" ) "02)" plane and to a type II (weaker metal/support interactions and better sulfurability) for C (0001), A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" planes. In addition, EXAFS results suggest a predominantly basal orientation of the sulfide phase on the C (0001) plane while a random orientation is highlighted on the other faces. The surface structural analogies between α and γAl2O3 polymorphs allows us to transpose these results to the industrial support (γ-Al2O3) and hence, to conclude that a proper control of the industrial support morphology constitutes a way to tune the genesis of the sulfide phase and improve the performances of hydrotreating catalysts
Hamieh, Balssam. „Genèse de catalyseurs d'HDS CoMoP sur Al2O3 (+Si) et SBA(+Al) : rôle du support sur la nature et la dispersion des phases oxydes et sulfures“. Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR049.
Hydrotreating processes (HDT) aim to purify petroleum fractions by reducing their sulfur content and by hydrogenating some of the aromatic compounds present in order to meet the specifications imposed for each type of fuel. These treatments are carried out under hydrogen pressure of the petroleum fraction in the presence of sulfided based catalysts supported on alumina. More and more stringent regulations on the sulphur content in fuels especially gas oils are driving the research for more efficient hydrodesulfurization (HDS) catalysts.The catalysts usually used in HDS of petroleum fractions are made of molybdenum disulfide nano-sheets promoted by cobalt and deposited on a support which is previously shaped according to the industrial application: extruded, beads.... A catalyst is obtained by impregnation of a solution containing the elements to be deposited (Co, Mo, and P), followed by different treatment steps: drying and calcination. The activation of the catalyst is then obtained after sulfurization between 300 and 400°C of the oxide precursor in the presence of H2/H2S.Gamma alumina is the most common used industrial support because it has a good mechanical strength, good textural properties (large specific surface...) and it is easily shaped. However the use of other supports has been investigated in order to increase the catalytic performances of these systems. Some studies have shown that silica can be used to obtain catalysts for which the activity per gram of active metals was higher than that observed with the alumina support. Nevertheless alumina supported catalysts are generally preferred HDS due to their better mechanical properties and higher metal content which can be deposit maintaining optimal dispersion. These disadvantages of silica constitute a barrier for the development of catalysts based on silica or other support. The idea of this thesis is to combine the interesting properties of alumina (textural, mechanical) and silica (surface properties) in order to obtain efficient catalysts for HDS of oil crudes.We have chosen to prepare catalysts based on mixed Al-Si supports obtained either by deposition of Si on industrial gamma alumina or by deposition of Al on mesoporous silica SBA-15 via various methodologies. The objective of the work is to study the impact of the nature of these mixed supports on the dispersion of the oxide and sulfide phases for an application in HDS.The first part of the thesis consist in optimizing the silica content added on the gamma alumina. CoMoP/Al-Six catalysts have been synthesized with different Si contents according to the number of OH groups located on the alumina (between 0 and 5 Si/nm2) and with a molybdenum content equal to 10% or 14% MoO3.The second part of the work consist in comparing two types of alumina A and B with different textural properties (pore volume and specific surface) in order to determine the the impact of these parameters on the dispersion of active species. We fixed the silica content at 3 Si/nm2 (the acidity of the initial support is not modified). Four series of catalysts were prepared by varying the MoO3 content (8-16% MoO3): CoMoxP/AlA, CoMoxP/AlB and CoMoxP/AlA-Si3, CoMoxP/AlB-Si3.In addition, a study of Mo, CoMo supported on Al and Al-Si3 catalysts was carried out for comparison with CoMoP catalysts.A final study focused on mixed supports obtained by addition of Al in SBA-15 using aluminium butoxide and alumina nitrate as precursors, the MoO3 content used is 14% and 28% MoO3.The thesis focuses on the characterization of the supports and catalysts at different stages of their preparation by different physicochemical and spectroscopic characterization techniques. An impact of the nature of the support as well as of the Si or Al content on the nature of the oxide phases (in particular CoMoO4, MoO3) and on the rate of sulphurization of the catalysts has been highlighted
Chamoumi, Mostafa. „Nouvelle génération de catalyseurs supportés par valorisation d'un résidu d'enrichissement (procédé UGS) d'une scorie de TiO2 : le catalyseur Ni-UGSO appliqué au reformage de méthane“. Thèse, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/10379.
Postole, Georgeta. „Le nitrure : un nouveau support en catalyse“. Lyon 1, 2006. http://www.theses.fr/2006LYO10106.
Molvinger, Karine. „Hydrogénations énantiosélectives sur catalyseurs mixtes : nickel-oxazaborolidines“. Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10229.
Barthe, Laurie Hemati Mehrdji Chaudret Bruno. „Synthèse et dépôt de nanoparticules métalliques dans un support poreux par imprégnation en voie sèche dans un lit fluidisé élaboration de catalyseurs supportés /“. Toulouse : INP Toulouse, 2008. http://ethesis.inp-toulouse.fr/archive/00000559.
GOETZ, JESSIE. „Catalyseurs d'hydrogenation selective, palladium et palladium-plomb deposes sur alumine alpha : effet d'interaction metal-support, effet d'alliage“. Université Louis Pasteur (Strasbourg) (1971-2008), 1995. http://www.theses.fr/1995STR1310H.
Lin, Liming. „Craquages d'alcanes sur catalyseurs zeolithiques : influence du nickel et du vanadium“. Poitiers, 1987. http://www.theses.fr/1987POIT2316.
Dupont, Colin. „La réaction d'ouverture de cycle de la tétraline sur des catalyseurs à base de carbure de molybdène : effet de l'acidité du support“. Paris 6, 2012. http://www.theses.fr/2012PA066391.
Selective ring opening reaction is, nowadays, the most efficient process to reach the current European Union specifications concerning diesel fuel cetane number (CN>51). The yield of this reaction is improved by using catalysts that possess both Brønsted acid sites and metallic sites. In the present work, bifunctional catalysts were synthesized with molybdenum carbide (Mo2C, metallic function) combined to acidic supports, whose acidity (strength and number) was varied: a commercial amorphous aluminosilicate, two zeolites (NaHY, beta) and two mesoporous materials (Al-MCM-41 synthesized from the assembly of preformed zeolite precursors (ZSM-5, beta) around a template). The metallic and the acidic properties were respectively studied by CO chemisorption and FTIR (CO at low temperature, pyridine). The structural properties of the supports and the catalysts were also characterized (XRD, TEM, N2-sorption). The bifunctional catalysts were tested for tetralin hydroconversion in the presence of 50 ppm of S at 350°C and 35. 5 bars. From the catalytic results and careful products identification, realized by 2D-GC, different reaction schemes were drawn. In the presence of Brønsted acid sites (medium or strong) and metallic sites (Mo2C<20 wt %), significant selective ring opening reaction yields are obtained (15% over 9. 5% Mo2C/MCM-41(beta)) but the products remain aromatic (and hence, low CN). At high Mo2C content (Mo2C>80 wt %), hydrogenation and isomerization reactions are favored at the expense of ring opening
Bara, Cédric. „Catalyseurs d'hydrotraitement à base de Mo supporté sur alumine : genèse de la phase active et effet de support par une approche science des surfaces“. Electronic Thesis or Diss., Paris 6, 2015. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2015PA066332.pdf.
The objective of this work was to develop a surface science approach to study the support effect on the genesis and structure of the active phase (molybdenum sulfide) on alumina supported Mo based hydrotreating catalysts supported on alumina which are used for petroleum refining. The originality of the work lies in the aqueous phase metal precursor deposition (molybdates) according to two synthetic routes (equilibrium adsorption and impregnation) on α alumina single crystals (γ alumina surrogate) with 4 different orientations (C (0001), R "(1" ¯("1" ) "02)" , A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" ). The combination of several physico-chemical characterization techniques (XPS, AFM, TEM, EXAFS) has shown that the surface structure of each crystal orientation governs the strength of metal/support interaction in the oxide state and thus the sulfidation degree and size of the sulfide active phase nanoparticles. This sulfide phase has been associated to a type I (strong metal/support interactions, lower sulfurability) for the R "(1" ¯("1" ) "02)" plane and to a type II (weaker metal/support interactions and better sulfurability) for C (0001), A "(11" ¯("2" ) "0)" and M "(10" ¯("1" ) "0)" planes. In addition, EXAFS results suggest a predominantly basal orientation of the sulfide phase on the C (0001) plane while a random orientation is highlighted on the other faces. The surface structural analogies between α and γAl2O3 polymorphs allows us to transpose these results to the industrial support (γ-Al2O3) and hence, to conclude that a proper control of the industrial support morphology constitutes a way to tune the genesis of the sulfide phase and improve the performances of hydrotreating catalysts
Harmel, Justine. „Synthèse de nano-catalyseurs hybrides à base de cobalt pour la catalyse Fischer-Tropsch“. Thesis, Toulouse, INSA, 2016. http://www.theses.fr/2016ISAT0035/document.
Due to the decreasing the oil resources, and because of the the fluctuations of the price as a result of the geopolitical context, the Fischer-Tropsch synthesis, that enables the production of hydrocarbons form the syngas mixture (CO and H2) in the presence of a catalyst based on cobalt or iron, has recently gained a renewed interest from industrial as well as form the academic communities. Although this reaction was discovered in 1923 by the Germans Franz Fischer and Hans Tropsch, the mechanisms that come into play during this reaction and the crucial properties of the catalyst properties remain uncertain. In this context, the work presented in this thesis, aims to investigate the impact of parameters such as the crystallographic structure and the shape of the cobalt nano-objects, which is the active phase of the catalyst for this reaction. For this purpose, model cobalt nano-objects were synthetized and their catalytic properties were studied. As a first step, a cobalt based catalyst exhibiting an hcp crystallographic structure and an anisotropic shape was prepared via a synthetic route involving the decomposition of an organometallic precursor of cobalt and leading to the formation of anisotropic cobalt nano-objects. Catalytic tests were then conducted in a slurry reactor, in collaboration with an industrial partner, IFP-EN. This collaboration allowed performing catalytic studies under conditions that are very close to the actual industrial conditions. These studies revealed an increased stability of these catalysts compared to reference catalysts that deactivate with time. Finally, several cobalt-based catalysts, supported on innovative supports, such as macrostuctured supports, allowing a better control of the exothermicity, were prepared and their catalytic properties studied on a fixed-bed reactor that was set up during the course of this thesis work
Bueno, Alejandra. „Catalyst supports with hierarchical and radial porosity : preparation, characterization and catalytic evaluation“. Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1249.
The vast majority of chemical processes are catalytic. Within the heterogeneous catalysis, industrial catalysts are bodies whose size ranges between 1 mm to 1 cm. For most catalysts, the active phase (i.e. metal nanoparticles) is dispersed in a mesoporous support having a high specific surface area. To overcome the problem of internal diffusional limitation, a secondary network of macropores is introduced within the catalyst support. This improves the diffusion of substrates. However, in the case where the catalytic reaction is particularly fast, the diffusion inside the porous support can remain limiting (Thiele modulus), resulting in a loss of catalytic effectiveness. The objective of this thesis is to study the catalytic effectiveness of a new alumina-based support shaped into spherical pellets, owing a radial macroporosity. In order to quantify the impact of this new porous structure, two model catalytic reactions were chosen to test the catalysts: CO oxidation and isooctane cracking. The catalytic activity was compared to reference commercial supports owing hierarchical porosity. For both reactions, the new support with radial porosity increases the activity from 25 to 95% approximately. On the basis of a fine characterization of the porosity of the beads (adsorption N2-77k, porosimetry Hg, X-ray microtomography), the catalytic activities were modeled. We conclude that the impact on the catalytic activity is essentially due to the radial porous design
Mennour, Ammar. „Caracterisation par spectroscopie infrarouge d'alumines modifiees et de catalyseurs w(mo) - ni(co) sulfures supportes sur alumine“. Caen, 1987. http://www.theses.fr/1987CAEN2019.
Michelot, Audric. „Immobilisation de catalyseurs sur un support solide inorganique à l'aide d'une chaîne moléculaire afin de permettre leur recyclage“. Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30345/document.
The asymmetric catalysis in homogeneous phase experienced a rapid development over the past decades and many complexes or ligands have been described in the literature. The separation and effective recycling of the catalyst (or ligands) appears expensive and as one of the challenges that combines both expectations of industrial organic synthesis and green chemistry. Among the various solutions proposed, immobilization of the catalyst on a solid support (powder) using a "molecular chain" appears as a seductive answer: the catalyst (metal-ligand pair) is recovered by simple filtration and can be reused. Our project is centered on chiral catalysts developed by our team and applied under Suzuki-Miyaura reactions and asymmetric hydrogenation. The use of hydroxyapatite (HAP) as organometallic catalysts inorganic support is a virtually unexplored field which nevertheless anchored in a process of sustainable development by responding to environmental and economic concerns: biocompatible synthetic materials in aqueous media (no organic solvent). We focused in particular grafting the HAP surface with functionalized alkoxysilanes (R-Si(OR')3). The nature of the interaction has been studied by various techniques (FTIR spectroscopy, Raman, NMR, XRD, SEM, TEM, etc.). These supports have shown moderate results in the Suzuki-Miyaura reaction. The use of mesoporous silica as a support has also been studied. We synthesized a variant of a functionalized ligand P,S ferrocenic have demonstrated good activities and enantioselectivities in homogeneous catalysis. Grafted on different media (HAP, silica, ...), we have made the first tests in catalysis of asymmetric hydrogenation and compared the influence of the media on activity
Krosnicki, Guillaume. „Utilisation de fullerène comme support de catalyseur pour les piles à combustible de type PEMFC“. Strasbourg, 2011. http://www.theses.fr/2011STRA6224.
This work concerns the study of new fullerene-based catalysts for the cathode of fuel cell type PEMFC. The use of fullerene C60, known to be stable, as a catalyst support and the ability to bind the platinum on the fullerene can hope to improve the resistance to degradation of the active layer. As a first step, a set of type catalyst MnC60 based on platinum and / or palladium atoms bonded to C60, called metallofullerenes, were synthesized and characterized physically and chemically. In parallel, non-noble catalysts based on iron phthalocyanine deposited on fullerene have been synthesized. The performance of these catalysts were electrochemically tested on a rotating ring-disk electrode, half-cell and, for best catalysts in fuel-cell, and compared with those obtained with reference commercial catalysts on carbon black Pt/C and PtCo/C. It appears from the study that the performance of metallofullerenes depends on the stoichiometry n of MnC60 compounds and best of them exhibit performance similar or even superior to those obtained with the reference catalysts. Non-noble catalysts on fullerene can obtain performance similar to those obtained with non-noble catalysts on carbon black. In addition, an initial study of metallofullerenes aging shows these compounds have a carbon corrosion resistance similar to reference catalysts