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Book Selective Hydrogenation of alpha beta unsaturated Aldehydes Over Metal Catalysts

Download or read book Selective Hydrogenation of alpha beta unsaturated Aldehydes Over Metal Catalysts written by Thomas Balder Ludwig Wolfgang Marinelli and published by . This book was released on 1993 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Selective Hydrogenation of alpha beta alpha Beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors

Download or read book Selective Hydrogenation of alpha beta alpha Beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors written by Laiqi Zhang and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrodynamics and mass transfer characteristics of a concurrent downflow contactor (CDC) are studied in this work in order to investigate the viability of this bubble column as a catalytic reactor for the hydrogenation of?,?-unsaturated aldehydes. Oxygen/water was used as the system throughout. In order to obtain reproducible results, a very effective gas-liquid separation method was conceived and developed after much trial and error work. Shutdown and deadleg gas holdup measuring methods were compared and it was found that the shutdown method is more reliable than the deadleg method. The hydrogenation of cinnamaldehyde using both in-house-prepared and commercial palladium, platinum and ruthenium catalysts was carried out in stirred tank reactors and cocurrent downflow reactors in order to study the kinetics and mass transfer characteristics and the selectivity towards the corresponding desired product, hydrocinnamaldehyde or cinnamyl alcohol. When palladium catalysts were used the desired product was hydrocinnamaldehyde. The effects of homogenous reactions, type of solvent, catalyst loading, temperature, pressure, reactant concentration and the effects of promoter or poison on the selectivity towards hydrocinnamaldehyde were investigated systematically. Aldehyde acetals were produced in polar solvents, but not in non-polar solvents. Two methods can be used to obtain hydrocinnamaldehyde selectivity without reduction of the carbonyl double bond: (1) by using non-polar solvents such as toluene; (2) by incorporating poisons or promoters into the reactant solution or onto the surface of the catalysts. 97% selectivity to hydrocinnamaldehyde was achieved. The effects of the solvent, temperature, pressure, catalyst loading, promoters, and reactants concentration on the kinetics were studied and the following reaction kinetics are proposed for the hydrogenation of cinnamaldehyde over non-modified palladium/charcoal catalysts in propan-2-ol and in toluene: Ra = kC\(_{Cat}\)C\(_{H2}\)C\(0_{CAL}\) The apparent activation energy varies with themperature range in propan-2-ol and is 65\(\pm\)5 kJ.mol\({-1}\) in toluene.

Book Selective Hydrogenation of Alpha Beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors

Download or read book Selective Hydrogenation of Alpha Beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors written by Lai Qi Zhang and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Selective Hydrogenation of alpha beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors

Download or read book Selective Hydrogenation of alpha beta unsaturated Aldehydes Towards Clean Synthesis Over Noble Metal Catalysts in Mass Transfer Efficient Three Phase Reactors written by Laiqi Zhang and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrodynamics and mass transfer characteristics of a concurrent downflow contactor (CDC) are studied in this work in order to investigate the viability of this bubble column as a catalytic reactor for the hydrogenation of ?,?-unsaturated aldehydes. Oxygen/water was used as the system throughout. In order to obtain reproducible results, a very effective gas-liquid separation method was conceived and developed after much trial and error work. Shutdown and deadleg gas holdup measuring methods were compared and it was found that the shutdown method is more reliable than the deadleg method. The hydrogenation of cinnamaldehyde using both in-house-prepared and commercial palladium, platinum and ruthenium catalysts was carried out in stirred tank reactors and cocurrent downflow reactors in order to study the kinetics and mass transfer characteristics and the selectivity towards the corresponding desired product, hydrocinnamaldehyde or cinnamyl alcohol. When palladium catalysts were used the desired product was hydrocinnamaldehyde. The effects of homogenous reactions, type of solvent, catalyst loading, temperature, pressure, reactant concentration and the effects of promoter or poison on the selectivity towards hydrocinnamaldehyde were investigated systematically. Aldehyde acetals were produced in polar solvents, but not in non-polar solvents. Two methods can be used to obtain hydrocinnamaldehyde selectivity without reduction of the carbonyl double bond: (1) by using non-polar solvents such as toluene; (2) by incorporating poisons or promoters into the reactant solution or onto the surface of the catalysts. 97% selectivity to hydrocinnamaldehyde was achieved. The effects of the solvent, temperature, pressure, catalyst loading, promoters, and reactants concentration on the kinetics were studied and the following reaction kinetics are proposed for the hydrogenation of cinnamaldehyde over non-modified palladium/charcoal catalysts in propan-2-ol and in toluene: Ra = kC\(-{Cat}\)C\(-{H2}\)C\( 0-{CAL}\) The apparent activation energy varies with themperature range in propan-2-ol and is 65\(\pm\)5 kJ.mol\( {-1}\) in toluene.

Book Selective Hydrogenation of alpha beta Unsaturated Aldehydes Over Ir Catalysts

Download or read book Selective Hydrogenation of alpha beta Unsaturated Aldehydes Over Ir Catalysts written by J. Gomez-Lopez and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Selective Hyddrogenation of alpha beta unsaturated Aldehydes Over Metal Catalysts

Download or read book Selective Hyddrogenation of alpha beta unsaturated Aldehydes Over Metal Catalysts written by Thomas Balder Ludwig Wolfgang Marinelli and published by . This book was released on 1993 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Selective Hydrogenation of alpha beta Unsaturated Aldehydes Over Ir Catalysts

Download or read book Selective Hydrogenation of alpha beta Unsaturated Aldehydes Over Ir Catalysts written by J. Gomez-Lopez and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Selective Hydrogenation and Transfer Hydrogenation Reactions

Download or read book Selective Hydrogenation and Transfer Hydrogenation Reactions written by Ronald Alvaro Farrar Tobar and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the research on catalysts active for the selective transfer hydrogenation (TH) of [alpha],[beta]-unsaturated carbonyl compounds using EtOH as H2 source as alternative to commonly used iPrOH. Furthermore, a base-free iron-based protocol is designed and optimized for the novel TH of ester compounds using EtOH as H2 source. In addition, the chemical activity of new single rhodium atoms on Al2O3 is explored. Using limonene as a model compound, only the terminal olefin was hydrogenated and the potential selective character of the catalyst is highlighted.eng

Book Selective Hydrogenation of an A b unsaturated Aldehyde Using Palladium Catalysts

Download or read book Selective Hydrogenation of an A b unsaturated Aldehyde Using Palladium Catalysts written by Matteo Navarria and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Heterogeneous Catalysis and Fine Chemicals II

Download or read book Heterogeneous Catalysis and Fine Chemicals II written by M. Guisnet and published by Elsevier. This book was released on 1991-04-19 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recession in the traditional heavy industries along with the development of advanced technologies in all the industrial countries has meant that the impact of heterogeneous catalysis in the synthesis of fine chemicals is becoming increasingly noticeable. The second International Symposium on Heterogeneous Catalysis and Fine Chemicals is to be seen in this perspective. Organised by the Laboratory of Catalysis in Organic Chemistry of the University of Poitiers within the framework of the International Symposia of the `Centre National de la Recherche Scientifique' (CNRS), the symposium provided an opportunity for contact between academic researchers and manufacturers, users (or potential users) of solid catalysts for fine chemical synthesis. The book gives an overall view of the problems encountered by academic and industrial researchers. A large variety of reactions are described, the emphasis being on selectivity: chemo-, regio-, stereoselectivity (even enantioselectivity) and on the change of these selectivities as a function of the characteristics of the surface sites (nature, distribution, etc.). The three themes of the symposium, hydrogenation, oxidation and acid-base catalysis were introduced in four plenary lectures and two invited communications, maintaining a balance between the industrial and the academic points of view. Some 60 research papers selected by the Scientific Committee were presented. All are reproduced in full in this proceedings volume.

Book Bimetallic Nanostructures

Download or read book Bimetallic Nanostructures written by Ya-Wen Zhang and published by John Wiley & Sons. This book was released on 2018-05-14 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: Systematically summarizes the current status and recent advances in bimetallic structures, their shape-controlled synthesis, properties, and applications Intensive researches are currently being carried out on bimetallic nanostructures, focusing on a number of fundamental, physical, and chemical questions regarding their synthesis and properties. This book presents a systematic and comprehensive summary of the current status and recent advances in this field, supporting readers in the synthesis of model bimetallic nanoparticles, and the exploration and interpretation of their properties. Bimetallic Nanostructures: Shape-Controlled Synthesis for Catalysis, Plasmonics and Sensing Applications is divided into three parts. Part 1 introduces basic chemical and physical knowledge of bimetallic structures, including fundamentals, computational models, and in situ characterization techniques. Part 2 summarizes recent developments in synthetic methods, characterization, and properties of bimetallic structures from the perspective of morphology effect, including zero-dimensional nanomaterials, one-dimensional nanomaterials, and two-dimensional nanomaterials. Part 3 discusses applications in electrocatalysis, heterogeneous catalysis, plasmonics and sensing. Comprehensive reference for an important multidisciplinary research field Thoroughly summarizes the present state and latest developments in bimetallic structures Helps researchers find optimal synthetic methods and explore new phenomena in surface science and synthetic chemistry of bimetallic nanostructures Bimetallic Nanostructures: Shape-Controlled Synthesis for Catalysis, Plasmonics and Sensing Applications is an excellent source or reference for researchers and advanced students. Academic researchers in nanoscience, nanocatalysis, and surface plasmonics, and those working in industry in areas involving nanotechnology, catalysis and optoelectronics, will find this book of interest.

Book Applications of Metal Organic Frameworks and Their Derived Materials

Download or read book Applications of Metal Organic Frameworks and Their Derived Materials written by Inamuddin and published by John Wiley & Sons. This book was released on 2020-06-10 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal–organic frameworks (MOFs) are porous crystalline polymers con­structed by metal sites and organic building blocks. Since the discovery of MOFs in the 1990s, they have received tremendous research attention for various applications due to their high surface area, controllable mor­phology, tunable chemical properties, and multifunctionalities, including MOFs as precursors and self-sacrificing templates for synthesizing metal oxides, heteroatom-doped carbons, metal-atoms encapsulated carbons, and others. Thus, awareness and knowledge about MOFs and their derived nanomaterials with conceptual understanding are essential for the advanced material community. This breakthrough new volume aims to explore down-to-earth applications in fields such as bio­medical, environmental, energy, and electronics. This book provides an overview of the structural and fundamental properties, synthesis strate­gies, and versatile applications of MOFs and their derived nanomaterials. It gives an updated and comprehensive account of the research in the field of MOFs and their derived nanomaterials. Whether as a reference for industry professionals and nanotechnologists or for use in the classroom for graduate and postgraduate students, faculty members, and research and development specialists working in the area of inorganic chemistry, materials science, and chemical engineering, this is a must-have for any library.