WorldCat Identities

Copéret, Christophe

Overview
Works: 31 works in 66 publications in 2 languages and 1,440 library holdings
Roles: Editor, Contributor, Thesis advisor, Other, Author, Opponent, htt, Publishing director
Classifications: QD506, 547.050453
Publication Timeline
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Most widely held works by Christophe Copéret
Chemistry of organo-hybrids : synthesis and characterization of functional nano-objects by Bernadette Charleux( )

11 editions published between 2014 and 2015 in English and held by 800 WorldCat member libraries worldwide

This book provides readers with a one-stop entry into the chemistry of varied hybrids and applications, from a molecular synthetic standpoint Describes introduction and effect of organic structures on specific support components (carbon-based materials, proteins, metals, and polymers). Chapters cover hot topics including nanodiamonds, nanocrystals, metal-organic frameworks, peptide bioconjugates, and chemoselective protein modification Describes analytical techniques, with pros and cons, to validate synthetic strategies Edited by internationally-recognized chemists from different backgr
Surface and interfacial organometallic chemistry and catalysis by Jean-Marie Basset( )

22 editions published between 2005 and 2011 in English and held by 603 WorldCat member libraries worldwide

Heterogeneous catalysis has been essential to the development of efficient chemical processes for more than a century, and this field has been traditionally part of the solid state chemistry and surface science communities. The design of better catalysts has raised the following questions: "what is the structure of the active sites?" and "how to control their nature?" The necessary need to develop more sustainable chemical processes and the success of homogeneous catalysis relying on molecular organometallic chemistry has led the community of molecular chemists to investigate the preparation of single-site heterogeneous catalysts. The authors discuss the molecular design, the preparation, the characterisation and the catalytic applications of well-defined oxides and metal particles. The readers will acquire a molecular understanding of heterogeneous catalysis, which will help them develop a critical view and which will attract them to study this fascinating field
Silica-Supported Pentamethylcyclopentadienyl Ytterbium(II) and Samarium(II) Sites: Ultrahigh Molecular Weight Polyethylene without Co-Catalyst( )

2 editions published in 2018 in English and held by 2 WorldCat member libraries worldwide

Abstract: Designing highly active supported ethylene polymerization catalysts that do not require a co-catalyst to generate electrophilic metal alkyl species is still a challenge despite its industrial relevance. Described herein is the synthesis and characterization of well-defined silica-supported cyclopentadienyl Ln II sites (Ln=Yb and Sm) of general formula [(≡SiO)LnCp*]. These well-defined surface species are highly activite towards ethylene polymerization in the absence of added co-catalyst. Initiation is proposed to occur by single electron transfer
Protein-nucleotide contacts in motor proteins detected by DNP-enhanced solid-state NMR by Thomas Wiegand( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Construction de cathodes et photocathodes moléculaires pour la production d'hydrogène by Nicolas Kaeffer( )

1 edition published in 2016 in English and held by 2 WorldCat member libraries worldwide

Solar fuels generated from the light-induced splitting of water into H2 and O2 is an appealing strategy for securing future energy. The use of platinum for catalyzing hydrogen evolution may be bypassed with earth-abundant catalysts. In a previous study, our lab realized the immobilization of a proton reduction catalyst, the cobalt diimine-dioxime molecular complex, within a cathode material steadily evolving H2 from fully aqueous media. In this work, we report on the implementation of this catalyst into light-driven devices. Operating conditions in the solvent of interest, water, were screened. The molecular catalyst degrades when free in solution, but retains activity when supported on an electrode, even in the presence of O2, and could thus be integrated into a tandem cell. Further on, new derivatives of the catalyst were developed for the attachment onto transparent conducting oxides. Co-grafted photocathodes were constructed by anchoring a functionalized catalyst along with photosensitizers onto p-type NiO. These architectures were checked by a whole set of analytical techniques and light-driven catalytic hydrogen evolution was achieved by photocathodes assessed under device-related photoelectrochemical conditions. Immobilizable dye-catalyst dyads were also successfully synthetized as alternative derivatives and open up new possibilities to develop molecular photocathodes
Surface Organometallic Chemistry: Paving the Way Beyond Well-Defined Supported Organometallics and Single-Site Catalysis by Christophe Copéret( )

1 edition published in 2017 in English and held by 2 WorldCat member libraries worldwide

Développement de catalyseurs hétérogènes à base de fer pour l'époxydation des oléfines by Charbel Roukoss( Book )

2 editions published in 2006 in French and held by 2 WorldCat member libraries worldwide

L'objectif de ce travail a été la synthèse de catalyseurs hétérogènes d'époxydation des oléfines. Actuellement cette réaction a été réalisée par des catalyseurs homogènes bio-inspirés et hétérogènes, conduisant ainsi à des procédés d'époxydation qui souffrent tous de problème de sélectivité et produisent une quantité énorme de sous produits. Au cours de ce travail, la préparation de nouveaux catalyseurs bien définis, à base de fer supportés sur oxydes, pour l'époxydation des oléfines a été abordée par la voie Chimie Organométallique de Surface. Plusieurs supports ont été sélectionnés (silice, SBA-15, alumine et silice-alumine). Trois types de précurseurs moléculaires (complexes organométalliques à base de Fer) sont utilisés : monomère stabilisé ou pas par un ligand et dimère. Leur greffage sur les différents supports ont permis d'obtenir trois classes différentes de catalyseurs: catalyseur monométallique avec ou sans ligand à base de Fer(II), catalyseur bimétallique à base de Fer(II) et catalyseur monométallique à base de Fer(III) dispersé sur support oxyde. Enfin l'activité de tous ces catalyseurs dans les réactions d'époxydation du cyclohéxène par H2O2 et du propène par N2O a été étudiée et un mécanisme d'oxydation a été proposé. Des activités intéressantes ont été obtenues, montrant ainsi la stratégie à adopter pour la prochaine génération de catalyseurs
Compréhension moléculaire du catalyseur de métathèse des oléfines Re2O7/Al2O3 "Site actif, initiation et désactivation" par Chimie Organométallique de Surface by Alain Salameh( Book )

2 editions published in 2006 in French and held by 2 WorldCat member libraries worldwide

Gamma-alumina: An Active Support to Obtain Immobilized Electron Poor Zr Complexes by Jérôme Joubert( )

1 edition published in 2008 in English and held by 2 WorldCat member libraries worldwide

Sites de surface de systèmes complexes : monosites, particules supportées vs. matériaux hybrides : structure, réactivité et mécanisme de formation : un point de vue RMN by David Gajan( )

1 edition published in 2010 in French and held by 1 WorldCat member library worldwide

In order to optimize heterogeneous catalysts through a molecular approach, whether based on single-sites or supported nanoparticles, it is necessary to access to a detailed understanding of its structures and formation mechanism. To reach this goal, classical characterization techniques (adsorption, IR, EXAFS, TEM...) have been combined with solid state NMR in order to access to the detailed structure and the dynamics of surface species. Here, we showed that the formation of well-dispersed Au(I) surface species (0.35/nm2) surrounded by hydrophobic groups (OSiMe3) by the controlled grafting of {AuN(SiMe3)2}4 and its conversion into 1.8nm gold nanoparticles supported on fully passivated silica upon a mild reduction under H2 (300°C). This system displays good activity and selectivity in air oxidation and hydrogenation reactions and provides new information on the activation of O2 on gold nanoparticles. By a similar approach, supported ruthenium nanoparticles have been prepared and characterized. Reactivity of Au and Ru nanoparticles with probe molecules (H2, phosphines, ethylene and CO) has been studied, in particular by NMR. However, the low density of these surface species, especially for supported nanoparticles is still one of the main problems, making difficult to obtain high quality NMR spectra in a reasonable time. Therefore, we have developed a method based on the enhancement of NMR signals of surface species via dipolar nuclear polarization (DNP). This very promising approach has first been applied very successfully to hybrid materials and silica; this opens new avenues in the characterization of surface species of materials and particularly heterogeneous catalysts
Preparation of Copper-based catalysts for the synthesis of Silicon nanowires by Arthur Roussey( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

The work presented in this PhD thesis aimed at the preparation of copper nanoparticles of controllable size and their utilization as catalysts for the growth of silicon nanowires in a process compatible with standard CMOS technology and at low temperature (< 450°C). The growth of silicon nanowires by Chemical Vapor Deposition (CVD) via the catalytic decomposition of a silicon precursor on metallic nanoparticles at low temperature (Vapor Solid-Solid process) was demonstrated to be possible from an oxidized Cu thin film. However, this process does not allow the control over nanowires diameter, which is controlled by the diameter of the nanoparticle of catalyst. In this PhD is presented a fully bottom-up approach to prepare copper nanoparticles of controllable size directly on a surface without the help of external stabilizer by mean of surface organometallic chemistry. First, the preparation of copper nanoparticles is demonstrated on 3D substrates (silica and titanium nitride nanoparticles), along with the fine comprehension of the formation mechanism of the nanoparticles as a function of the surface properties. Then, this methodology is transferred to planar (2D) substrates typically used in microelectronics (silicon wafers). Surface structure is demonstrated to direct the Cu nanoparticles diameter between 3 to 40 nm. The similarities between the 2D and 3D substrates are discussed. Finally, the activity of the Copper nanoparticles in the growth of Silicon nanowire is presented and it is demonstrated that in our conditions a critical diameter may exist above which the growth occurs
Approche moléculaire du design et de la synthèse de nanoparticules supportées et non-supportées à base de Pt et Pd by Pierre Laurent( )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

The goal of this thesis is to develop synthesis methods for platinum and palladium based nanoparticles. We mainly focused on three synthesis pathways, i) Surface Organometallic Chemistry (SOMC), ii) metal organic chemical vapor deposition (MOCVD) and iii) a colloidal approach. Surface organometallic chemistry allowed the synthesis of silica supported nanoparticles with sizes of about 2 nm. The transfer of this methodology to cerium oxide has been carried out and allowed obtaining nanoparticles of less than 1.5 nm in diameter. Those researches had for purpose the synthesis of oxidation catalysts supported on ceria used for automotive pollution and paves the way for the surface organometallic chemistry on this oxide. By MOCVD, Pt nanoparticles from 4 to 6 nm were synthesized onto gas diffusion layers (GDL) for applications in fuel cell catalysis. Electrocatalysis results demonstrated the viability of this synthesis method and the efficiency of these catalysts for the Oxygen Reduction Reaction (ORR). For the same application, nanoparticles of Pt, Pd and Pt/Pd in various proportions were synthesized by the colloidal approach. These nanoparticles stabilized by octylsilane had a size ranging from 1.5 to 1.8 nm. For platinum, the influence of the organometallic precursor and temperature have been studied and synthesis without adding external reducing (H2) and from PtII precursor allowed obtaining stable nanoparticles of 1.2 nm. Their use for the ORR has shown interest to form alloys, the Pt/Pd 3:1 composition demonstrating an improvement by a factor of 1.4 compared to pure Pt
Exploration of Transition Metal Sulfide Catalysts Prepared by Controlled Surface Chemistry by Rick Arneil Arancon( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

L'hydrotraitement est un procédé catalytique important dans le raffinage du pétrole qui utilise des catalyseurs bimétalliques sulfurés NiWS ou NiMoS (ou CoMoS) supportés sur alumine. Leur mode conventionnel de préparation implique l'imprégnation d'une solution aqueuse de sels de Mo/W et de Ni/Co, puis l'activation par un agent sulfo-réducteur (H2S/H2). Pour répondre aux exigences environnementales et améliorer l'efficacité de l'hydrotraitement, des améliorations permanentes de la performance de ces systèmes catalytiques sont attendues. Ce travail se concentre sur la préparation de catalyseurs d'hydrotraitement hautement actifs par une approche de chimie de surface contrôlée (CSC) qui implique l'imprégnation successive de précurseurs moléculaires de MoV et NiII en solvant organique sur un support silice-alumine traité thermiquement. Dans la première partie de cette thèse, la genèse de la phase active du catalyseur CSC et conventionnel Mo et NiMo est étudiée par quick-XAS combinée à d'autres techniques (chimiométrie, XPS, RPE, STEM-HAADF, modélisation moléculaire). Nous proposons ainsi des structures moléculaires depuis les précurseurs oxydes de Mo et Ni supportés jusqu'aux nombreuses espèces intermédiaires (oxysulfure et sulfures) en fonction de la température. Cette analyse multi-technique permet d'abord de révéler les spécificités de la genèse des catalyseurs CSC et conventionnels qui peuvent expliquer leurs différentes activités catalytiques. Ensuite, elle révèle également de nouvelles connaissances sur les mécanismes d'insertion du Ni dans la phase NiMoS en fonction de la préparation. Dans la seconde partie, la possibilité de remplacer Co et Ni comme promoteurs est explorée. Ceci est entrepris en synthétisant des catalyseurs alternatifs de type XYMoS, où X et Y sont des métaux de transition 3d. Comme suggéré par des études de modélisation quantiques antérieures, certaines formulations XYMoS peuvent présenter un effet de synergie analogue à ceux des phases actives CoMoS et NiMoS. L'étude des formulations les plus prometteuses méritent d'être approfondies afin de mieux comprendre leur fonctionnement
Silica-supported isolated molybdenum di-oxo species: formation and activation with organosilicon agent for olefin metathesis12( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Abstract : A well-defined silica-supported molybdenum dioxo species, (#xE002;SiO)2 Mo(O)2, prepared via Surface Organometallic Chemistry, is highly active in metathesis upon reaction with organosilicon reducing agent. Abstract : A well-defined silica-supported molybdenum dioxo species, (#xE002;SiO)2 Mo(O)2, is prepared by grafting Mo(O)2 [OSi(O t Bu)3]2 on partially dehydroxylated silica SiO2-700, followed by thermal treatment under high-vaccum and calcination. Activated by an organosilicon agent the resulting material is active for olefin metathesis at 30 °C
Photocatalyse bimétallique appliquée aux carburants solaires by Steven Bardey( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Le CO2, qui jadis a joué un rôle important dans l'apparition de l'oxygène et donc de la vie sur terre, atteint aujourd'hui des concentrations atmosphériques si élevées qu'il provoque un changement climatique qui bouleverse l'équilibre des écosystèmes et pourrait mettre en péril la vie sur terre. Il est donc urgent d'inverser la tendance des émissions de CO2 anthropogéniques et de développer des sources d'énergie propres. Ce projet s'inscrit dans cette double problématique, il vise à utiliser l'énergie solaire pour valoriser le CO2 en « carburants solaires », par photocatalyse. La préparation de photocatalyseurs M/TiO2 et M1M2/TiO2 a permis de montrer que le dépôt de nanoparticules métalliques (Au, Pt, Pd, Ag, Cu) est une voie d'optimisation efficace pour la photo-réduction du CO2. Ceci est dû à différents effets bénéfiques induits par les métaux et leur association, qui ont été étudiés et correlés à l'activité photocatalytique quand cela fut possible. La construction d'un système plasmonique possédant une résonnance élargie, et son association avec TiO2 ou avec g-C3N4, a notamment permis de mettre en évidence un effet plasmonique d'intensification du champ proche. Cet effet permet d'éxacerber l'absorption du semi-conducteur et est très certainement responsable de l'amélioration de l'activité photocatalytique et de l'orientation de la sélectivité observées
Benchmarked Intrinsic Olefin Metathesis Activity: Mo vs. W( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Abstract : Combining Surface Organometallic Chemistry with rigorous olefin purification protocol allows evaluating and comparing the intrinsic activities of Mo and W olefin metathesis catalysts towards different types of olefin substrates. While well-defined silica-supported Mo and W imido-alkylidenes show very similar activities in metathesis of internal olefins, Mo catalysts systematically outperform their W analogs in metathesis of terminal olefins, consistent with the formation of stable unsubstituted W metallacyclobutanes in the presence of ethylene. However, Mo catalysts are more prone to induce olefin isomerization, in particular when ethylene is present, probably because of their propensity to undergo more easily reduction processes. Abstract
Molecular approach to heterogeneous catalysis( Book )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

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1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Synthesis of ruthenium complexes having one or more N-heterocyclic carbene ligands supported on hybrid mesostructured silicas and their use in the hydrogenation of carbon dioxide by Mathieu Baffert( )

1 edition published in 2011 in English and held by 1 WorldCat member library worldwide

The goal of this PhD was to elaborate supported Ru-NHC catalytic materials based on hybrid organic-inorganic materials having imidazolium units perfectly distributed within a silica matrix. Passivation of these imidazolium materials followed by formation of NHC-carbene and reaction with [RuCl2(p-cymene)]2 provided these well-defined surface sites of general structures RuCl2(NHC)(L), where L was para-cymene (p-cymene) or THF depending on the reaction conditions, which could be further replaced by PMe3. These systems were then tested in the hydrogenation of CO2 in presence of amine to give formamides. The mono-NHC systems were highly active only in the presence of PMe3 ligands, but suffered from Ru leaching, evidencing the low stability of the NHC-Ru bond under the reaction conditions. On the other hand, dinuclear bis-NHC Ru systems were also developed, and they displayed much improved activity and stability in the hydrogenation of CO2 in the presence of PMe3 compared to the mono-NHC systems. This allowed the use of much higher reaction temperatures (200 °C) and provided heterogeneous catalysts with performances close to those obtained with the best homogeneous catalysts, Cl2Ru(dppe)2
 
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Chemistry of organo-hybrids : synthesis and characterization of functional nano-objects
Covers
Surface and interfacial organometallic chemistry and catalysis
Alternative Names
Christophe Copéret French Chemist

Christophe Copéret scheikundige

Copéret, Ch.

Languages
English (49)

French (6)