Thematische Bibliographien / Catalyseur de surface

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Auswahl der wissenschaftlichen Literatur zum Thema „Catalyseur de surface“

Autor: Grafiati

Veröffentlicht am 19. Oktober 2023

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Zeitschriftenartikel zum Thema "Catalyseur de surface"

Zalma, Roger, Lionel Bonneau, Jeanine Fournier, Joëlle Guignard, Françoise Borg und Henri Pezerat. „Hydrodésazotation de l'indole sur catalyseur fer supporté sur amiante“. Canadian Journal of Chemistry 65, Nr. 3 (01.03.1987): 523–27. http://dx.doi.org/10.1139/v87-091.

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The aim of this study is to examine hydrodenitrogenation (HDN) of indole on asbestos catalysts (chrysotile and crocidolite) under hydrogen pressure. HDN is carried out according to two competitive pathways, either via ortho-ethylaniline or via ortho-toluidine. This reaction is assisted by increase of temperature and pressure and by pre-reduction of the asbestos. Particles of Fe0on the fibre surface are formed from the original material. Their presence plays a role in the initial breaking of the C—N bond and in the hydrogenation reaction.

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Merabet, Smail, Abdelkrim Bouzaza, Mohamed Bouhelassa und Dominique Wolbert. „Modélisation et optimisation de la photodégradation du 4-méthylphénol dans un réacteur à recirculation en présence d’UV/ZnO“. Revue des sciences de l'eau 22, Nr. 4 (22.10.2009): 565–73. http://dx.doi.org/10.7202/038331ar.

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Résumé L’étude de la photodégradation du 4-méthylphénol a été menée sur un pilote à recirculation. Cette molécule a été prise comme composé modèle pour le traitement des effluents de l’industrie avicole. Ce travail a consisté en l’optimisation et la modélisation de l’élimination du 4-méthylphénol par photocatalyse en présence de ZnO. L’utilisation des plans d’expériences, et en particulier de la méthodologie de surface de réponse (RSM) et un plan central composite (CCD), a permis la détermination de l’influence des effets simultanés et de l’interaction des paramètres opératoires sur le rendement de la photodégradation. Les paramètres étudiés sont la concentration initiale en 4-méthylphénol, la concentration en catalyseur et le débit de recirculation de la solution. Les résultats montrent que l’application de la RSM permet de décrire d’une manière correcte l’influence de ces trois paramètres expérimentaux sur l’efficacité du traitement. Les valeurs optimales des paramètres donnant un rendement maximal (100 %) ont pu être déterminées. Les modèles de second ordre obtenus, pour le rendement de dégradation et pour l’abattement de DCO, ont été validés en utilisant différentes approches statistiques. L’utilisation de la méthode ANOVA a montré que les modèles sont hautement significatifs et en bonne adéquation avec les résultats expérimentaux.

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Hurren, C. J., R. T. Liu, Xin Liu und X. G. Wang. „Photo-Catalysis of Red Wine Stains Using Titanium Dioxide Sol-Gel Coatings on Wool Fabrics“. Advances in Science and Technology 60 (September 2008): 111–16. http://dx.doi.org/10.4028/www.scientific.net/ast.60.111.

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This paper investigated the use of titanium dioxide sol-gel coatings to photo-catalyse red wine stains on wool fabrics. Coatings were produced by the hydrolysis and condensation of titanium butoxide (Ti(OC4H9)4) on the surface of wool fabrics after pad application. Coatings were partially converted to the anatase form of titanium dioxide by prolonged immersion in boiling water. The coating presence was confirmed using scanning electron microscopy, UVspectrophotometry and atomic force microscopy. Coated samples were measured for photo-catalytic activity by degrading red wine stains from the surface of the coated fabric. The level of photocatalysis was determined for each of the coating systems after 168 hours. Red wine stains were photo-catalysed and level of staining was reduced from the UV exposed surface of the coated wool fabric.

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Bergel, Alain. „Recent Advances in Electron Transfer Between Biofilms and Metals“. Advanced Materials Research 20-21 (Juli 2007): 329–34. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.329.

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Microbial biofilms produce electrochemical interactions with metal surfaces by following a wide variety of different electron exchange pathways. Reviewing the mechanisms identified in the biocorrosion of steels leads us to distinguish direct and indirect mechanisms for biofilm-catalysed cathodic reactions. Indirect mechanisms are due to the production of metal oxides or hydrogen peroxide (aerobic corrosion) or metal sulphides (anaerobic corrosion), which further react with the metal surface. Direct mechanisms involve adsorbed biocompounds, generally enzymes or their active sites, which catalyse the cathodic reduction of oxygen for aerobic biocorrosion or the proton/water reduction in anaerobic processes. Recent studies dealing with the role of hydrogenases in anaerobic corrosion have shed light on the important role of phosphate species via so-called cathodic deprotonation. Advances in the development of microbial fuel cells have also resulted in new concepts, mainly for oxidation processes. Some microbial cells have been shown to be able to produce their own electron mediators. Others can transfer electrons directly to electrodes through membrane-bound electron shuttles or achieve long-range transfer through conductive pili.

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Mozaceanu, Cristina, Christopher G. P. Taylor, Jerico R. Piper, Stephen P. Argent und Michael D. Ward. „Catalysis of an Aldol Condensation Using a Coordination Cage“. Chemistry 2, Nr. 1 (25.01.2020): 22–32. http://dx.doi.org/10.3390/chemistry2010004.

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The aldol condensation of indane-1,3-dione (ID) to give ‘bindone’ in water is catalysed by an M8L12 cubic coordination cage (Hw). The absolute rate of reaction is slow under weakly acidic conditions (pH 3–4), but in the absence of a catalyst it is undetectable. In water, the binding constant of ID in the cavity of Hw is ca. 2.4 (±1.2) × 103 M−1, giving a ∆G for the binding of −19.3 (±1.2) kJ mol−1. The crystal structure of the complex revealed the presence of two molecules of the guest ID stacked inside the cavity, giving a packing coefficient of 74% as well as another molecule hydrogen-bonded to the cage’s exterior surface. We suggest that the catalysis occurs due to the stabilisation of the enolate anion of ID by the 16+ surface of the cage, which also attracts molecules of neutral ID to the surface because of its hydrophobicity. The cage, therefore, brings together neutral ID and its enolate anion via two different interactions to catalyse the reaction, which—as the control experiments show—occurs at the exterior surface of the cage and not inside the cage cavity.

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Wong, W.-Y., S. Lim, Y.-L. Pang, C.-H. Lim, F.-L. Pua und G. Pua. „Response surface optimisation of biodiesel synthesis using biomass derived green heterogeneous catalyst“. IOP Conference Series: Materials Science and Engineering 1257, Nr. 1 (01.10.2022): 012010. http://dx.doi.org/10.1088/1757-899x/1257/1/012010.

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Abstract Although homogeneous alkali-catalysed transesterification is the typical process used in biodiesel production, it caused complications in downstream separation processes and an oversupply of glycerol as a by-product. The present work studied the synthesis of a novel sulfonated biomass-derived solid acid catalyst and its application in biodiesel production via interesterification of oleic acid. Solid acid catalysts were prepared by direct sulfonation via thermal treatment with concentrated sulfuric acid. The design of experiments was conducted via four-factors central composite design (CCD) coupled with response surface methodology (RSM) analysis. The parameters considered for optimisation included carbonisation and sulfonation temperatures, catalyst loading and reaction time, each varied at five levels. The maximum yield of fatty acid methyl ester (FAME) was obtained using optimum parameters as carbonisation temperature of 586 °C, sulfonation temperature of 110 °C, catalyst loading of 10.5 wt.% and reaction time of 7 h was 54.3 % based on the theoretical ester formation. A quadratic mathematical model in RSM was successfully established that can make effective predictions about the anticipated biodiesel yield. This study proved that the low-cost heterogeneous catalyst derived from biomass waste with a simple production route could catalyse the interesterification process under moderate process conditions.

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Papageorgiou, G., J. D. Major und K. Durose. „Substrate geometry CdTe solar cells with catalytically-grown nano-rough surfaces“. MRS Advances 1, Nr. 14 (2016): 985–90. http://dx.doi.org/10.1557/adv.2016.153.

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ABSTRACTSubstrate geometry CdTe solar cells have been modified with the addition of metal-catalysed nano-structures in order to influence their efficiency. Conditions for the growth of Au- and Bi-catalysed nanostructures were explored. The substrate devices themselves comprised indium tin oxide/CdS/CdTe/Mo foil and were developed using the MgCl2 alternative to the usual CdCl2 processing – this yielded open circuit voltages of up to 740 mV. It was demonstrated that the addition of Au-catalysed nanowires to 200 nm thick CdTe films on glass substrates decreased their optical transmission by 10%, this being significantly higher than for thick films. However, reproducibility issues with forming Bi nanostructures limited the device modification tests to the use of Au-catalysed wires, and these always acted to depress photovoltaic performance.

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Tsuji, Hideto, und Hideshi Hattori. „Oxide Surfaces that Catalyse an Acid–Base Reaction with Surface Lattice Oxygen Exchange: Evidence of Nucleophilicity of Oxide Surfaces“. ChemPhysChem 5, Nr. 5 (17.05.2004): 733–36. http://dx.doi.org/10.1002/cphc.200400009.

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Chen, L., F. Qi, B. Xu, Z. Xu, J. Shen und K. Li. „The efficiency and mechanism of γ-alumina catalytic ozonation of 2-methylisoborneol in drinking water“. Water Supply 6, Nr. 3 (01.07.2006): 43–51. http://dx.doi.org/10.2166/ws.2006.726.

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The efficiency and mechanism in degradation of 2-methylisoborneol (MIB) as a taste and odour compound in drinking water were studied under the condition where γ-alumina catalysed ozonation. As a result, γ-alumina can show distinct activity in enhancing the efficiency of ozonation of MIB. Tert-butyl alcohol had a remarkable effect on the removal efficiency of catalytic ozonation of MIB. The surface charge status, surface hydroxyl group status of γ-alumina, and pH values of the solution can be linked together. When the pH value of the solution was near the pHzpc of γ-Al2O3, there was observable activity in the catalysed ozonation process. Rct, which denoted the relative concentration of hydroxyl radical (·OH), was much higher in the catalysed ozonation process than in the ozonation process. This result further illuminated that γ-Al2O3 can promote ozone decomposition to produce ·OH. Finally, the effect of rP/I on catalysed ozone decomposition and ozone decomposition was investigated.

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Wang, Dianzhan, Ye Gu, Zhaoshun Yang und Lixiang Zhou. „Synthesis and assessment of schwertmannite/few-layer graphene composite for the degradation of sulfamethazine in heterogeneous Fenton-like reaction“. Royal Society Open Science 7, Nr. 7 (Juli 2020): 191977. http://dx.doi.org/10.1098/rsos.191977.

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Schwertmannite (sch), an iron oxyhydrosulfate mineral, can catalyse a Fenton-like reaction to degrade organic contaminants, but the reduction of Fe(III) to Fe(II) on the surface of schwertmannite is a limiting step for the Fenton-like process. In the present study, the sch/few-layer graphene (sch–FLG) composite was synthesized to promote the catalytic activity of sch in a Fenton-like reaction. It was found that sch can be successfully carried by FLG in sch–FLG composite, mainly via the chemical bond of Fe–O–C on the surface of sch–FLG. The sch–FLG exhibited a much higher catalytic activity than sch or FLG for the degradation of sulfamethazine (SMT) in the heterogeneous Fenton-like reaction, which resulted from the fact that the FLG can pass electrons efficiently. The degradation efficiency of SMT was around 100% under the reaction conditions of H 2 O 2 200–500 mg l −1 , sch–FLG dosage 1–2 g l −1 , temperature 28–38°C, and initial solution pH 1–9. During the repeated uses of sch–FLG in the Fenton-like reaction, it maintained a certain catalytic activity for the degradation of SMT and the mineral structure was not changed. In addition, SMT may be finally mineralized in the Fenton-like reaction catalysed by sch–FLG, and the possible degradation pathways were proposed. Therefore, the sch–FLG is an excellent catalyst for SMT degradation in a heterogeneous Fenton-like reaction.

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Dissertationen zum Thema "Catalyseur de surface"

Muller, Sébastien. „Caractérisation de catalyseurs deNOx et deN2O par modélisation LSER (Linear Solvation Energy Relationship) : étude structure-propriétés“. Thesis, Metz, 2008. http://www.theses.fr/2008METZ048S.

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Cette étude présente la caractérisation de catalyseurs deNOx ou deN2O en termes d’une relation structure-propriétés. Ceci afin de comprendre les interactions intervenant entre les catalyseurs et les espèces gazeuses présentes dans le système étudié et d’aider à la formulation de ces matériaux. Cette modélisation est réalisée par l’approche LSER (Linear Solvation Energy Relationship), qui permet de mettre en avant les interactions (polaire, acido-basique…) entrant en jeu lors du processus d’adsorption de composés à la surface des matériaux. Ces études montrent que l’approche LSER permet de suivre l’évolution de la surface des catalyseurs après différents traitements comme l’ajout de phases actives. La comparaison des affinités catalyseur-composés gazeux permet de mettre en avant les différences observées au niveau des équations LSER, principalement pour l’évolution de la polarité, la basicité et l’acidité, paramètres qui sont fortement impliqués lors de l’adsorption d’aromatiques, d’alcools ou d’eau par exemple. Cette méthode permet également de mettre en avant certaines étapes clefs des différents processus d’élimination des NOx ou N2O, étapes qui varient en fonction du processus, tel que la forte adsorption des réducteurs sur le catalyseur pour le deNOx charbon alors que le même effet entraine des performances plus faibles dans le cas du deN2O. La méthode LSER, qui constitue une approche thermodynamique, ouvre une voie et est un moyen supplémentaire dans la compréhension des phénomènes intervenants dans les processus de catalyse deNOx et deN2O ; et montre que les phénomènes d’adsorption ne sont pas, selon les cas, prépondérants dans les performances des catalyseurs
This study presents the characterisation of deNOx and deN2O catalysts in terms of structure-properties relationship in order to understand the different interactions involved between catalysts and gaseous species present in the system and to contribute to the formulation of these materials. The LSER modelisation (Linear Solvation Energy Relationship) allows us to prove the interactions involve during the adsorption process of compounds at the surface. The evolution of the catalyst’s surface after different treatments is following by the LSER approach. The comparison of the affinity proves the differences observed in the LSER equations: especially the polarity, basicity and acidity terms, implicated in aromatics, alcohol and water adsorption. This method shows differences between different steps in the processes of NOx and N2O elimination (as the strong adsorption of reducers on the catalyst for the coal-deNOx, whereas the same effect involves weaker performances in the case of the deN2O. The LSER method which consists in a thermodynamic approach, is a new useful technique for the understanding of the phenomenon involved in the deNOx and deN2O catalysis processes. It also demonstrates that the adsorption processes are not so important in the catalysts performances

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Théodet, Manuel. „Nouvelle génération de précurseurs "bulk" de catalyseur d'hydrodésulfuration synthétisés en milieu fluides supercritique“. Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00559113.

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L'objet de ce travail de thèse porte sur la synthèse originale en milieu fluide supercritique (FSC) de précurseurs « bulk » de catalyseurs d'hydrodésulfuration (HDS) à haute surface spécifique (SBET), destinés à l'HDS de composés soufrés réfractaires tels que le 4,6 diméthyldibenzothiophène (4,6¬ DMDBT). Ce projet a été réalisé en collaboration entre l'Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS) et l'Instituto de Tecnología Química de Valencia (ITQ-CSIC) dans le cadre du réseau européen d'excellence Functional Advanced Materials and Engineering of Hybrids and Ceramics (FAMEnoe). Les études à l'ICMCB se sont portées sur l'optimisation des paramètres de synthèse en milieu FSC de NixCo1-xMoO4 (0 ≤ x ≤ 1) (précurseurs métalliques, solvant, température, pression). Des poudres de précurseurs « bulk » majoritairement composées de la phase hydratée (NiMoO4.0,75H2O) - phase la plus active en HDS - de composition contrôlée et pouvant atteindre près de 200 m2.g-1 ont été obtenues et caractérisées. Les propriétés catalytiques de ces précurseurs « bulk » après sulfuration ont ensuite été testées à l'ITQ sur la réaction de Deep-HDS d'un mélange modèle et d'une fraction pétrolière réelle. L'étude souligne plus particulièrement leurs meilleures capacités d'hydrogénation et de catalyse de l'HDS du 4,6 DMDBT que le catalyseur commercial utilisé comme référence dans ces travaux.

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Calmettes, Stéphanie. „Conception d'un catalyseur par greffage d'un complexe de ruthénium en milieu confiné ; Application à l'oxydation sélective“. Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2008. http://tel.archives-ouvertes.fr/tel-00292814.

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Un complexe de ruthénium supporté est synthétisé à l'intérieur d'une LUS, silice mésostructurée poreuse de type MCM-41, via une approche multi-étapes. L'ingénierie de surface est réalisée selon un procédé contrôlé de protection / déprotection des groupements silanols de surface. Un ancre moléculaire finalisée par un groupement pyridine, Py@LUS, est distribuée de manière homogène grâce à une technique de pochoir moléculaire, puis le complexe [Ru(dmp)2Cl2] (dmp = 2,9-diméthyl-1,10-phénantroline) est introduit. Les matériaux intermédiaires sont caractérisés à chaque étape par un panel de techniques, dont DRX, analyses élémentaires, ATG, 29Si et 13C MAS-NMR, DRUV, FT-IR, Raman et cyclovoltampérométrie. L'intégrité de la structure poreuse, la formation du complexe supporté et sa localisation au sein de l'espace confiné des pores de la matrice silicique sont confirmées. Le matériau final est actif et sélectif dans l'oxydation catalytique du thioanisole en sulfoxyde.

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Zhang, Kun. „Mesostructured porous materials : Pore and surface engineering towards bio-inspired synthesis of heterogeneous copper catalysts“. Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2008. http://tel.archives-ouvertes.fr/tel-00310153.

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Le contrôle fin de la structure et de la chimie de surface en milieu confiné a été développé dans des silices poreuses mésostucturées de type MCM-41 pour synthétiser des catalyseurs hétérogènes combinant confinement moléculaire, hydrophobicité et spécificité de sites à l'instar des métalloprotéines. La surface considérée comme lisse a en fait une rugosité de type alvéolaire due à l'empreinte de la tête ammonium du tensioactif de synthèse. Pour des températures croissantes du traitement hydrothermal, la taille des mésopores augmente par érosion de cette rugosité puis diminue par épaississement des parois. On a aussi trouvé des conditions de synthèse de zéolihes mésoporeuses avec une micro- et mésoporosité hiérarchisée. Ces surfaces sont polyfonctionnalisées grâce à la technique de pochoir moléculaire pour isoler des fonctions bidentatés aminoéthylaminopropyles par des groupements hydrophobes triméthylsimyles. Les ions cuivriques sont alors retenus dans le matériau par complexation à ces fonctions diamino.

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El, Mansour Abdellah. „Chimie organométallique de surface sur métaux étude de la préparation de catalyseurs bimétalliques par réaction de Sn(Bu) avec le catalyseur Rh/SiO sous différents états d'oxydation“. Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375994230.

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Mansour, Abdellah El. „Chimie organométallique de surface sur métaux : étude de la préparation de catalyseurs bimétalliques par réaction de Sn(Bu)4 avec le catalyseur Rh-SiO2 sous différents états d'oxydation“. Lyon 1, 1986. http://www.theses.fr/1986LYO11713.

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El, Mouahid Souad. „Hydrogénation de liaisons C=C en solution aqueuse de différentes compositions sous contrôle du potentiel du catalyseur au platine“. Poitiers, 1999. http://www.theses.fr/1999POIT2352.

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Le but de ce travail etait d'etudier le role du potentiel d'un catalyseur au platine et aussi l'influence de la composition de la solution sur les proprietes hydrogenantes du catalyseur. L'hydrogenation de l'acide maleique a servi de reaction-test. Lors d'une hydrogenation en phase aqueuse, le potentiel du catalyseur peut etre etabli spontanement en presence des reactifs ou controle au moyen d'un potentiostat (en presence ou en absence d'hydrogene moleculaire). Il a ete montre que l'activite catalytique du platine depend de la source d'hydrogene actif et du mode de controle du potentiel. Une promotion de l'activite hydrogenante du platine par le controle exterieur du potentiel et en presence de dihydrogene a ete trouvee dans un milieu d'acide perchlorique. L'influence des anions presents dans la solution sur l'adsorption des reactifs (acide maleique et hydrogene) sur le platine et sur l'hydrogenation de l'acide maleique, a ete aussi etudiee. L'activite catalytique observee depend de la nature des anions et devient importante dans un milieu contenant des anions faiblement adsorbes alors que les anions fortement adsorbes inhibent l'adsorption dissociative et la mobilite de l'hydrogene sur la surface du platine. De meme, un effet de la nature des cations presents dans la solution, a ete trouve lors de cette etude. Cet effet depend des proprietes physiques (rayon ionique, electropositivite) de ces cations. Il ressort de ce travail que le potentiel du catalyseur est un parametre important en hydrogenation des liaisons c=c en phase aqueuse dont l'influence depend du type des especes actives et des proprietes d'adsorption de l'interface metal/solution (nature des anions et des cations presents dans la solution).

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Salameh, Alain. „Compréhension moléculaire du catalyseur de métathèse des oléfines Re2O7/Al2O3 "Site actif, initiation et désactivation" par Chimie Organométallique de Surface“. Lyon 1, 2006. http://www.theses.fr/2006LYO10221.

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Le greffage CH3ReO3 sur γ-Al2O3 conduit à la formation de plusieurs espèces de surface : certaines résultantes de la coordination des ligands oxo sur des sites acides de Lewis et d'autres résultantes de l'activation C-H du groupement méthyle de CH3ReO3 sur les défauts de l'alumine. Des réactions de métathèse croisés ont montré que seulement 14% du nombre total de Re est actif, et que l'espèce active provient de [AlsCH2ReO3], l'état stable du catalyseur. D'autre part, la métathèse de propène dans un réacteur à flux continu a montré que le CH3ReO3/Al2O3 est un système très actif, mais qui se désactive rapidement. De plus, les sites actifs de CH3ReO3/Al2O3 sont "Z sélectifs". Contrairement à CH3ReO3/Al2O3, le carbene est formé in situ pour le système Re2O7/Al2O3, par la réaction entre l'oléfine et un ligand oxo, probablement via une réaction pseudo-Wittig. Les études cinétiques dans un réacteur à flux continu ont montré que les sites actifs de Re2O7/Al2O3 sont également "Z sélectifs"
Grafting CH3ReO3 on γ-Al2O3 leads to the formation of several surface species : some resulting from coordination of the oxo ligands onto Lewis acid sites and some resulting from the C-H activation of the methyl group of CH3ReO3 on the defect sites of alumina. Cross-metathesis experiments have shown that only 14% of the total Re was active and that the active species was originating from [AlsCH2ReO3]. This species corresponds to the resting state of the catalyst. Moreover, propene metathesis in a flow reactor has shown that CH3ReO3/Al2O3 is highly active, but deactivates rapidly with time. Additionally, contact time studies have infered that the active sites of CH3ReO3/Al2O3 are "Z selective". In contrast to CH3ReO3/Al2O3, the carbene is formed in situ for Re2O7/Al2O3, and results from the reaction of the olefin and an oxo ligand, probably through a pseudo-Witting reaction. Kinetics studies in a flow reactor have shown that the active sites of Re2O7/Al2O3 are also "Z selective"

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Mougin, Pascal. „Diffusion et réaction catalytique à l'interface d'un objet fractal en deux dimensions : le peigne du diable“. Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_MOUGIN_P.pdf.

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Ce mémoire s'intéresse aux phénomènes de diffusion et de réaction catalytique dans un réseau bidimensionnel de pores à caractère fractal: le peigne du diable. La géométrie de cette structure est introduite et des grandeurs permettant la comparaison avec des supports catalytiques usuels sont définies. Ce peigne est fractal par son contour. Il présente ainsi une interface spécifique importante, justifiant son emploi pour des réactions de surface. Des simulations de marche au hasard montrent que la diffusion est modifiée en régime de Knuden. Nous avons simulé le comportement du peigne du diable dans le cas de réactions simples sur son contour. Un nouveau régime de fonctionnement apparait, le régime fractal caractérisé par un flux de production indépendant de la cinétique chimique: l'objet possède des propriétés d'auto-adaptation. Les systèmes composites ont des comportements similaires à ceux obtenus avec des supports classiques. En revanche, dans le cas de l'empoisonnement du catalyseur, la structure fractale du peigne stabilise le flux de consommation pendant une durée d'empoisonnement plus longue que celle d'un support classique. La validation des simulations nécessite la réalisation de cette structure. La réaction test est la décomposition d'ozone sur oxydes métalliques. La fabrication du peigne du diable utilise des microtechniques: électroérosion, liga, stéréophotolithographie. Des collaborations avec d'autres laboratoires de recherche développant ces techniques ont été initiées. Les résultats obtenus avec ces peignes ont permis de valider une partie des simulations numériques

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Idriss, Hicham. „Etude des especes de surface sur catalyseurs cu-zn dans la synthese du methanol“. Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13071.

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Bücher zum Thema "Catalyseur de surface"

Scanning tunneling microscopy in surface science, nanoscience and catalysis. Weinheim: Wiley-VCH, 2010.

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1939-, King D. A., und Woodruff D. P. 1944-, Hrsg. The chemical physics of solid surfaces. Amsterdam: Elsevier, 1993.

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1945-, Więckowski Andrzej, Savinova Elena R. 1950- und Vayenas C. G, Hrsg. Catalysis and electrocatalysis at nanoparticle surfaces. New York: Marcel Dekker, 2003.

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Somorjai, Gabor A. Introduction to surface chemistry and catalysis. 2. Aufl. Hoboken, N.J: WILEY, 2010.

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Introduction to surface chemistry and catalysis. New York: Wiley, 1994.

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Campbell, Ian M. Catalysis at surfaces. London: Chapman and Hall, 1988.

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1936-, Paál Zoltán, und Menon P. G. 1932-, Hrsg. Hydrogen effects in catalysis: Fundamentals and practical applications. New York: M. Dekker, 1988.

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Catalysis and surface properties of liquid metals and alloys. New York, N.Y: M. Dekker, 1987.

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1941-, Suzuki Motoyuki, Hrsg. Fundamentals of adsorption: Proceedings of the Fourth International Conference on Fundamentals of Adsorption, Kyoto, May 17-22, 1992. Tokyo: Kodansha, 1993.

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Metal-Catalysed Reactions of Hydrocarbons. Springer, 2010.

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Buchteile zum Thema "Catalyseur de surface"

Wells, Peter B. „Selectivity in Metal-Catalysed Hydrogenation“. In Surface Chemistry and Catalysis, 295–349. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4757-6637-0_12.

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Wiesen, P., J. Kleffmann, R. Kurtenbach und K. H. Becker. „Surface Catalysed Conversion of NO2 a New Source of Atmospheric N2O?“ In Non-CO2 Greenhouse Gases: Why and How to Control?, 311–16. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0982-6_35.

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Alista, Diska Indah, Kamisah Delilawati Pandiangan, Khoirin Nisa, Wasinton Simanjuntak, Erika Noviana und Selvia Anggraini Hasan. „Optimization of Zeolite-X Catalysed Palm Oil Transesterification Using Response Surface Methodology“. In Proceedings of the 12th International Conference on Green Technology (ICGT 2022), 232–38. Dordrecht: Atlantis Press International BV, 2023. http://dx.doi.org/10.2991/978-94-6463-148-7_24.

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Niccolai, Gerald P., und Jean-Marie Basset. „New Processes for Carbon-Carbon Bond Activation Catalysed by Oxide Supported Surface Organometallic Complexes“. In Catalytic Activation and Functionalisation of Light Alkanes, 111–24. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-0982-8_5.

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Dobson, C. M., J. A. Gerrard und A. J. Pratt. „Proteins as catalysts“. In Foundations of Chemical Biology. Oxford University Press, 2001. http://dx.doi.org/10.1093/hesc/9780199248995.003.0005.

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This chapter reviews how proteins adopt well-defined three-dimensional structures and are capable of binding small molecules reversibly at one or more specific sites on their surfaces. It refers to enzymes that generally catalyse specific reactions of particular molecules and the enhancements of the reaction rate that are often remarkably high. It also emphasizes the efficiency of enzymes as the rate-limiting factor in the catalysed reaction is the diffusion of the reactants to the enzyme. The chapter focuses on the appreciation of the chemistry of enzyme catalysis that provides insights into the biochemical details of cells and chemical catalysis. It looks at features of enzyme catalysis by illustrating triose phosphate isomerase in great detail.

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Atkins, Peter, Julio de Paula und David Smith. „Heterogeneous catalysis“. In Elements of Physical Chemistry. Oxford University Press, 2016. http://dx.doi.org/10.1093/hesc/9780198727873.003.0043.

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This chapter studies heterogeneous catalysis, in which the catalyst and the reagents are in different phases. A common example is a solid that increases the rate of a gas-phase reaction. The solid provides a surface to which the reactants bind and so facilitates encounters between reactants. In general, heterogeneous catalysts are highly selective and to find an appropriate catalyst each reaction must be investigated individually. Two techniques have revolutionized the study of surfaces in recent years: scanning tunnelling microscopy (STM) and atomic force microscopy (AFM). Ultimately, the key to the operation of a heterogeneous catalyst is the attachment of molecules to a surface by the process called adsorption. The chapter then differentiates between physisorption and chemisorption, before looking at adsorption isotherms. It also considers the mechanisms of surface-catalysed reactions, including the Langmuir–Hinshelwood mechanism and the Eley–Rideal mechanism.

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Stamm, Th, H. W. Kouwenhoven und R. Prins. „Zeolite Catalysed Rearrangement of Aromatic Amines“. In Studies in Surface Science and Catalysis, 543–50. Elsevier, 1993. http://dx.doi.org/10.1016/s0167-2991(08)63364-9.

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Jiménez, O., T. E. Müller, W. Schwieger und J. A. Lercher. „Hydroamination reactions catalysed with beta zeolites“. In Studies in Surface Science and Catalysis, 2788–94. Elsevier, 2004. http://dx.doi.org/10.1016/s0167-2991(04)80555-x.

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Elings, J. A., H. E. B. Lempers und R. A. Sheldon. „Zeolite-catalysed rearrangement of isophorone oxide“. In Studies in Surface Science and Catalysis, 1165–72. Elsevier, 1997. http://dx.doi.org/10.1016/s0167-2991(97)80753-7.

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Gigante, B., C. Santos, M. J. Marcelo-Curto, C. Couranceau, J. M. Silva, F. Alvarez, M. Guisnet, E. Selli und L. Forni. „Zeolite-catalysed hydrolysis of aromatic amides“. In Studies in Surface Science and Catalysis, 547–54. Elsevier, 1997. http://dx.doi.org/10.1016/s0167-2991(97)80949-4.

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Konferenzberichte zum Thema "Catalyseur de surface"

Kulić Mandić, Aleksandra, Milena Bečelić-Tomin, Đurđa Kerkez, Gordana Pucar Milidrag, Vesna Pešić und Miljana Prica. „A mini review: Optimal dye removal by fenton process catalysed with waste materials“. In 10th International Symposium on Graphic Engineering and Design. University of Novi Sad, Faculty of technical sciences, Department of graphic engineering and design,, 2020. http://dx.doi.org/10.24867/grid-2020-p21.

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Large quantities of solid waste from different industries are commonly disposed in landfills, where can generate wide range of environmental problems. Therefore, the aim of this paper is to give insight on the usage of various waste materials as oxidation catalysts in different Fenton processes for dye removal. In that manner the circular value chain of these materials will be reinforced, obtaining disposal cost reduction and further value addition. Some of industrial wastes (fly ash, electric arc furnace dust, red mud, coal bottom ash, activated carbon from biomass, etc.) that have been used to catalyse Fenton reaction in various researches are reviewed from optimization point of view. Both types of optimization, one-factor-at-a-time (OFAT) and response surface methodology (RSM) are investigated. The study revealed that factors as catalyst concentration, pH value, hydrogen peroxide concentration, dye concentration and reaction time are main factors that influence final Fenton capacity as oxidation process catalysed with reviewed waste materials.

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AYLWARD, Nigel. „A Prebiotic Surface Catalysed Photochemically Activated Synthesis of L-Cysteine“. In International Conference on Biological Engineering and Pharmacy 2016 (BEP 2016). Paris, France: Atlantis Press, 2017. http://dx.doi.org/10.2991/bep-16.2017.1.

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Veser, G., G. Friedrich, M. Freygang und R. Zengerle. „A Simple and Flexible Micro Reactor for Investigations on Heterogeneous Catalytic Gas Phase Reactions“. In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-1243.

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Abstract Micro reactors, i.e. chemical reactors with characteristic dimensions in the sub-millimeter range, hold great promise for novel chemical process routes (Lerou 1996, Wengeng 1996). Among their potential advantages for chemical processes are: the very small thermal inertia, allowing for a very direct control of temperature as a very critical reaction parameter; their inherent safety due to both the small reactant volume being present at any time in the reactor and the well controllable reactor and reaction conditions; and their small dimensions, making them easy to integrate into existing processes or to use them where space requirements are critical. Furthermore, for heterogeneously catalysed gas phase reactions, micro reactors offer the additional advantage of allowing for a very large surface to volume ratio. This should at least theoretically allow for an effective suppression of homogeneous gas phase reactions, since free surfaces typically are strong sinks for radical species which are required to keep the homogeneous reaction alive. Therefore, it should be possible to conduct a heterogeneously catalysed reaction involving a mixture of potentially flammable (if not explosive) gases in a micro reactor without any danger of open flames and explosion. This has the two-fold advantage, that not only the reaction becomes intrinsically safe, but it should also be possible to study heterogeneously catalysed high-temperature reactions without influences by parallel homogeneous reaction Pathways, making it a very valuable tool for research into this class of reactions.

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Hu, Jianqiang, Guanglong Liu und Feng Xie. „Tribological Synergism Between Borates and Sn(II) or Sn(IV) Compounds“. In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79649.

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Dibutyl tin and stannous dialkyldithiocarbamates were synthesized. A four-ball tester was used to evaluate the tribological performances of these additives plus organic borate in a mineral oil. The results indicate that the combination of an oil-soluble tin compounds such as dibutyl tin and stannous dialkyldithiocarbamates with organic borates gave better antiwear protection to base oil than either component separately. The surface examination of the rubbing zone indicated that the atomic concentration of tin produced on the boundary layers by such combinations was greater than those without borates. On the basis of the results of tribological and chemical investigation, an antiwear synergistic mechanism can be postulated in which borates with electron-deficient p orbits in boron catalyse the triboreduction of tin compounds on rubbing surfaces.

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Willinger, Marc. „In situ SEM as monolayer sensitive surface science tool: From 2D film growth to the observation of catalysed surface reactions“. In European Microscopy Congress 2020. Royal Microscopical Society, 2021. http://dx.doi.org/10.22443/rms.emc2020.1458.

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Bond, Ian, Tim Coope, Richard Trask, Greg McCombe, Duncan Wass und Ulrich Mayer. „Multi-Mode Self-Healing in Composite Materials Using Novel Chemistry“. In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-4949.

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A novel Lewis acid-catalysed self-healing system is investigated for implementation in epoxy-based fibre reinforced polymer (FRP) composite materials. The catalyst, scandium(III) triflate, is selected using a qualitative approach and subsequently embedded with pre-synthesised epoxy-solvent loaded microcapsules, into an epoxy resin. Healing is initiated when microcapsules are ruptured at the onset of crack propagation. The epoxy monomer healing agent contained within, actively undergoes ring-opening polymerisation (ROP) on contact with the locally placed catalyst, forming a new polymer to bridge the two fractured crack surfaces. Self-healing performance is quantified using tapered double cantilever beam (TDCB) epoxy resin test specimens and the effects of microcapsule loading, microcapsule content and healing temperature are all independently considered. As an initial proof of concept study, results show that a material recovery value of greater than 80% fracture strength is achieved for this novel Lewis acid-catalysed self-healing epoxy resin. The same self-healing agent system was subsequently demonstrated in a larger scale FRP component by incorporating both a microcapsule and hollow glass fibre (HGF) delivery system within an FRP laminate using a End-Notched Flexure (ENF) test configuration.

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Rajalakshmi, N., R. Rajini und K. S. Dhathathreyan. „High Performance Polymer Electrolyte Membrane Fuel Cell Electrodes“. In ASME 2004 2nd International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2004. http://dx.doi.org/10.1115/fuelcell2004-2484.

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Several methods are being attempted to improve the performance of PEM Fuel cell electrodes so that the cost of the overall system can be brought down. The performance can be improved if the utilization of the catalyst in the electrode increases. One of the early successful method was to add a proton conducting polymer, such as NafionR to the catalyst layer. However there is a limit to the amount of NafionR that can be added as too much NafionR affect the gas diffusion. The other method is to increase the surface area of the catalyst used which has also been adequately demonstrated. Alternative methods for providing increased proton conductivity and catalyst utilization are thus of great interest, and a number of them have been investigated in the literature. One method that is being extensively investigated is to introduce the catalyst onto the polymer electrolyte membrane followed by lamination with gas diffusion electrode. In the present work, we have carried out two methods i) screen print the catalyst ink on the NafionR membrane ii) catalyze the NafionR membranes by reducing a suitable platinum salt on the membrane. Standard gas diffusion electrodes were then laminated onto this membrane. The performances of Membrane Electrode Assemblies (MEAs) prepared by these routes have been compared with the commercially available Gore catalysed membrane. It was observed that catalysed NafionR membranes show a better performance compared to the catalyst ink screen printed on the NafionR membrane and commercial Gore membrane under identical operating conditions. However MEAs with Gore membrane give a better performance in the iR region compared to the other MEAs prepared using NafionR membrane. The lesser performance with Gore membrane is probably due to the limitations in the lamination method employed.

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Bhushan, Indu. „Efficient media for high production of microbial lipase from Bacillus subtilis (BSK-L) using response surface methodology for enantiopure synthesis of drug molecules“. In 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.044.

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Lipases are a multipurpose enzyme that holds a significant position in industrial applications due to its ability to catalyse a large number of reactions such as hydrolysis, esterification, interesterification, transesterification which makes it a potential candidate. It is also used for the separation of chiral drugs from the racemic mixture and this property of lipase is considered very important in pharmaceutical industries for the synthesis of enantiopure bioactive molecules. Assuming the tremendous importance of lipases, as stereoselective biocatalysts, in pharmaceuticals and various other commercial applications, industrial enzymologists have been forced to search for those microorganisms which are able to produce novel biocatalysts at reasonably high yield. In the present study microbial lipase was isolated from the water sample of pond at Katra, Jammu and Kashmir (India). This enzyme has shown wide specificity and higher enantioselectivity, which make it pharmaceutical important enzyme. To make it economical for industrial application, it was produced on cheap nutrient media using Response Surface Methodology and got maximum production. It was used for resolution of chiral drugs and the significant results obtained during the course of work shall have potential towards pharmaceutical industries.

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Dooi jewaard, G., D. J. Binnema und C. Kluft. „CONTACT ACTIVATION AND SINGLE-CHAIN UROKINASE-TYPE PLASMINOGEN ACTIVATOR“. In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642958.

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For many years it is known that activation of the factor XII (FXII) -prekallikrein (PKK)- kininogen system of coagulation (contact activation) also may be involved in activation of fibrinolysis. Despite the numerous efforts over the past two decades to clarify this process, our current insights in this matter are far from complete. Also the physiological meaning of this possible interlinkage of coagulation and fibrinolysis is still uncertain; clearcut clinical manifestations in patients deficient in FXII or PKK are not found.No doubt, activation of fibrinolysis is a much more complicated process than it originally was thought to be, and it is only recently that the importance of urokinase for fibrinolysis in the circulation became clear. Two pathways of plasminogen (Pig) activation may be distinguished: 1. the extrinsic system, catalysed by t-PA, which upon stimulus is increasingly released from the endothelial cells of the vessel wall and 2. the intrinsic system, catalysed via Pig proactivators which circulate in the blood at a fairly constant level of concentration. The discovery that the virgin 55 kD urokinase molecule in fact is a single-chain proenzym (now denoted by scu-PA, single-chain urokinase-type PA), the notion that 55 kD scu-PA occurs in the blood and that its concentration even among individuals is fairly constant (2.1+/-0.4 ng/ml, n=52), and the observation that the efficacy of scu-PA is fibrin selective, all are recent findings pointing to the involvement of scu-PA in the intrinsic system.Still the relation between contact activation and the activation of scu-PA is obscure. Active KK, for instance, is an effective activator of 55 kD scu-PA, but proteolytic cleavage of scu-PA resulting in an active molecule, is readily achieved in plasma’s deficient in FXII or PKK. In addition, a portion of Pig activator activity which is dependent for its activation on FXII and PKK, is fully recovered in plasma’s artificially depleted in 55 kD scu-PA. Yet, both portions are activated by negatively charged surfaces or dextransulphate (DXS) as a substitute! These observations have led to the concept of two co-ordinative pathways of Pig activation for the intrinsic system: one containing scu-PA, the other containing FXII, PKK and a postulated Pig proactivator (note that the Pig activator activities of FXIIa and KK per se do not account for the latter portion of activity). Until recently in both pathways was a missing link: in the former it was the step between the negatively charged surface and scu-PA, in the latter it was the postulated Pig proactivator between active KK and Pig. This year, however, it became clear that in plasma artificially depleted in u-PA, still a substantial amount of protein immunochemically related to u-PA, can be detected (at least 35 ng/ml), but only after SDS PAGE. Part of this protein is a single-chain 110 kD molecule which in plasma can be converted to a cleaved molecule with Pig activator activity provided the plasma contains FXII and PKK. Although the relation with the 55 kD scu-PA remained unclear, the discovery of this 110 kD PA with latent urokinase antigen, undoubtedly, explains the missing link between KK and Pig. The other missing link still remains unexplained. It could be an in vitro artefact by DXS causing scu-PA catalysed activation of Pig as fibrin clots do. Since subsequently generated plasmin is capable of activation of both scu-PA and FXII, the two intrinsic pathways are thus interlinked via feed-back activation and consequently may be co-operative in function.

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Souza, V. A. D., und A. Neville. „Corrosion of WC-Co-Cr Cermet Coatings using In-Situ Atomic Force Microscopy“. In ITSC2003, herausgegeben von Basil R. Marple und Christian Moreau. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.itsc2003p0395.

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Abstract Most of the early applications of thermal spray coatings were focused towards providing a remedy to excessive wear degradation. However, as the introduction of such coatings into wider industrial sections increases there is also exposure to other potential degradation processes - aqueous corrosion is one such process. The complex microstructures in cermet coatings have been shown to translate to complex modes of corrosion attack. In this paper an electrochemical test methodology to probe the local/micro aspects of corrosion initiation and propagation will be described. A new electrochemical cell has been devised in which the corrosion can be followed `live` and in `real time`. The surface is subjected to in-situ imaging by Atomic Force Microscopy (AFM). This paper reports some of the exciting findings which have enabled the sequence of corrosion events in cermet coatings to be defined. The study has revealed that a precursor to coating degradation is the attack of the Co-base matrix. This sets up an environment which can catalyse WC dissolution. The practical and fundamental importance of the results will be discussed.

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