Download or read book Heterogeneous Oxidation of Alcohols written by Hamza Mounzer and published by . This book was released on 2009 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heterogeneous Oxidation of Alcohols written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The selective oxidation of alcohols is one of the most challenging reactions in green chemistry. While the current chemical industry uses organic and inorganic oxidants to produce carbonyl compounds, it is highly desirable to use a heterogeneous catalyst for the efficient oxidation of alcohols. The present research is focused on increasing the activity and selectivity towards the corresponding carbonyl of the heterogeneous oxidation for alcohols. The low activity of 5 wt.%Pt-1 wt. %Bi/Carbon for the oxidation of 2-octanol was investigated in a 500ml stirred tank reactor. The fast reaction rate drops dramatically from 0.23 M/hr to 0.006 M/hr after 15 minutes reaction time when heptane was used as solvent. Different possible causes such as overoxidation, leaching and poisoning were examined. It was found that the loss of high conversion rate was due to product adsorption and hence, different solvents were investigated. A mixture of 16-18% v/v dioxane in heptane was able to effectively regenerate active sites and allow a constant reaction rate of 0.07M/hr. The effects of temperature and pressure were also studied. Gas-liquid, liquid-solid and internal mass transfer effects were determined experimentally and semi-empirically. Six different Langmuir-Hinshelwood rate models were examined where a modified model based on Schuurman et al. (1992) was found to adequately describe the experimental data. The novel 2.5%Au-2.5%Pd/titania catalyst was investigated for the oxidation of benzyl alcohol. Different parameters such as catalyst oxidation state, pressure and stirrer design were studied to increase the activity and selectivity of the catalyst. The selectivity was shown to be highly dependent on the oxygen concentration. Therefore, the pressure, temperature, catalyst treatment were optimised and the reactor configuration was re-designed to enhance oxygen transport to the catalyst. While the conversion rate was unaffected by the oxygen concentration, the catalyst pre-treatmen.
Download or read book Oxidation of Alcohols Using Heterogeneous Au TiO2 Catalysts written by Devon Indar and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alcohol Oxidation written by Steffan Paterson and published by Nova Science Publishers. This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few years, there has been a growing interest in the development of sustainable processes for large-scale production of commodities. As such, Alcohol Oxidation: Reaction, Effects and Applications addresses recent developments in metal-catalyzed selective oxidation reactions of alcohols to carbonyl-containing compounds under unconventional conditions. Following this, the authors examine how simple alcohols have been used as feedstocks for the preparation of a variety of enantioenriched substances. Cascade reactions allow for the elaboration of complex molecules from simple starting materials in a very efficient way. Several bonds can be made in one-pot procedures without the need for intermediates to be isolated. Metal-organic frameworks and covalent organic frameworks are two classes of highly porous materials that have been heavily investigated in recent years. As such, in this compilation the authors focus on the use of metal-organic frameworks as heterogeneous oxidation catalysts. Enantiopure alcohols are important starting materials and intermediates for the synthesis of many biologically active compounds and fine chemicals. The use of enzymes for the kinetic resolution of racemates has produced affordable enantiopure compounds in good yields, however non-enzymatic chiral catalytic systems have been gaining ground. Accordingly, the effective non-enzymatic oxidative kinetic resolutions of racemic alcohols and related compounds such as diols or benzoins are summarized and discussed. Lastly, the potential employment of the electrochemical process to oxidize alcohols in a more efficient way than the usual chemical method is presented. The use of the electrode potential as a controllable variable and driving force of the process allows for the oxidation of some alcohol molecules without of the very aggressive nature of reactants.
Download or read book Fine Chemicals through Heterogeneous Catalysis written by R. A. Sheldon and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, the chemical industry is under increased pressure to develop cleaner production processes and technologies. Much effort is devoted to the development of heterogeneous catalysts and their application in industrial-scale organic synthesis. This handbook concentrates on current attempts, focusing on fine chemical production. With contributions from an impressive array of international experts, this is essential reading for everyone interested in the advances in this field.
Download or read book Modern Heterogeneous Oxidation Catalysis written by Noritaka Mizuno and published by John Wiley & Sons. This book was released on 2009-11-18 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a gap in the current literature, this comprehensive reference presents all important catalyst classes, including metal oxides, polyoxometalates, and zeolites. Readers will find here everything they need to know -- from structure design to characterization, and from immobilization to industrial processes. A true must-have for anyone working in this key technology.
Download or read book Transition Metal Catalysis in Aerobic Alcohol Oxidation written by Francesca Cardona and published by Royal Society of Chemistry. This book was released on 2015 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the search for environmentally benign procedures for the oxidation of alcohols and gives an overview of their transition-metal-catalyzed aerobic oxidation.
Download or read book Nanocatalysis written by Ulrich Heiz and published by Springer Science & Business Media. This book was released on 2007-01-10 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanocatalysis, a subdiscipline of nanoscience, seeks to control chemical reactions by changing the size, dimensionality, chemical composition, and morphology of the reaction center and by changing the kinetics using nanopatterning of the reaction center. This book offers a detailed pedagogical and methodological overview of the field. Readers discover many examples of current research, helping them explore new and emerging applications.
Download or read book Liquid Phase Aerobic Oxidation Catalysis written by Shannon S. Stahl and published by John Wiley & Sons. This book was released on 2016-10-10 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book to place recent academic developments within the context of real life industrial applications, this is a timely overview of the field of aerobic oxidation reactions in the liquid phase that also illuminates the key challenges that lie ahead. As such, it covers both homogeneous as well as heterogeneous chemocatalysis and biocatalysis, along with examples taken from various industries: bulk chemicals and monomers, specialty chemicals, flavors and fragrances, vitamins, and pharmaceuticals. One chapter is devoted to reactor concepts and engineering aspects of these methods, while another deals with the relevance of aerobic oxidation catalysis for the conversion of renewable feedstock. With chapters written by a team of academic and industrial researchers, this is a valuable reference for synthetic and catalytic chemists at universities as well as those working in the pharmaceutical and fine chemical industries seeking a better understanding of these reactions and how to design large scale processes based on this technology.
Download or read book Vanadium Catalysis written by Manas Sutradhar and published by Royal Society of Chemistry. This book was released on 2020-11-05 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vanadium is one of the more abundant elements in the Earth’s crust and exhibits a wide range of oxidation states in its compounds making it potentially a more sustainable and more economical choice as a catalyst than the noble metals. A wide variety of reactions have been found to be catalysed by homogeneous, supported and heterogeneous vanadium complexes and the number of applications is growing fast. Bringing together the research on the catalytic uses of this element into one essential resource, including theoretical perspectives on proposed mechanisms for vanadium catalysis and an overview of its relevance in biological processes, this book is a useful reference for industrial and academic chemists alike.
Download or read book Noble Metal Heterogeneous Catalysts for Aerobic Alcohol Oxidation written by and published by . This book was released on 2015 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transformation of hydrocarbon feedstocks to complex molecules found in the fine chemical, agro chemical, and pharmaceutical industries require selective oxidations to impart the desired functionality. Oxidation of alcohols is commonly done employing harsh and potentially hazardous oxidants with stoichiometric amounts of byproducts being produced. The use of O2 as the terminal oxidant provides a safe and environmentally benign alternative with selectivity control being realized through the use of a catalyst. The use of a Ru(OH)x/Al2O3 catalyst for the oxidation of alcohols to aldehydes or ketones was studied for applicability and scalability in a continuous process. The catalyst was found to undergo rapid deactivation in the first 50-100 turnovers. High yields of diverse aldehydes and ketones were realized in the continuous process over the deactivated Ru(OH)x/Al2O3 catalyst. The discovery of a new heterogeneous catalyst was accomplished through rapid admixture screening and optimization using design of experiment techniques. The optimized catalyst compositions of PdBi0.47Te0.09/C (PBT-1) and PdBi0.35Te0.23/C (PBT-2) were found to be very active and selective for the aerobic oxidation of 1-octanol to methyl octanoate. These optimized catalysts show high yields of many diverse methyl esters from the oxidation of alcohols, and their stability was demonstrated in a continuous process achieving nearly 60,000 turnovers with no apparent loss in activity. The role of the Bi and Te promoters and mechanism of the PBT-2 catalyst was explored through kinetic studies and characterization of the catalyst. Through the use of kinetics and other mechanistic probes we discovered that the reaction shows saturation dependence in [substrate] and [K2CO3] and is first order in pO2, supporting a Langmuir-Hinshelwood mechanism with the reaction occurring between alkoxide and O2 adsorbed to the catalyst. The promoters are proposed to protect the Pd catalyst from over oxidation to inactive PdOx species as well as prevent side reactions (Bi) and electronically modify the Pd (Te). Oxidation of alcohols to aldehydes or nitriles was demonstrated in a continuous process using a CuI/TEMPO catalyst. The oxidation to the nitrile was accomplished through the addition of anhydrous ammonia, and excellent yields were observed from the oxidation of diverse primary benzylic alcohols.
Download or read book Metal Organic Frameworks as Heterogeneous Catalysts written by Francesc X. Llabrés i Xamena and published by Royal Society of Chemistry. This book was released on 2013-07-01 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines the latest research and discovery in the use of MOFs in catalysis, highlighting the extent to which these materials have been embraced by the community.
Download or read book Copper and Iron Incorporated MCM 41 for the Heterogeneous Oxidation of Benzyl Alcohol written by Atikah Aini Abdullah and published by . This book was released on 2015 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Heterogenous Palladium and Related Catalysts for Aerobic Oxidation of Primary Alcohols written by Maaz S. Ahmed and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of aerobic oxidation methods is of critical importance for the advancement of green chemistry, where the only byproduct produced is water. Recent work by our lab has produced an efficient Pd based heterogenous catalyst capable of preforming the aerobic oxidation of a wide spectrum of alcohols to either carboxylic acid or methyl ester. The well-defined catalyst PdBi0.35Te0.23/C (PBT/C) catalyst has been shown to can perform the aerobic oxidation of alcohols to carboxylic acids in basic conditions. Additionally, we explored this catalyst for a wide range of alcohols and probed the nature of the selectivity of PBT/C for methyl esterification over other side products. Finally, means by which the catalyst operates with respect to oxidation states of the three components, Pd, Bi, and Te, was probed. Carboxylic acids are an important functional group due to their prevalence in various pharmaceutically active agents, agrochemicals, and commodity scale chemicals. The well-defined catalyst PBT/C catalyst was discovered to be effective for the oxidation of a wide spectrum of alcohols to carboxylic acid. The demonstrated substrate scope and functional group tolerance are the widest reported for an aerobic heterogeneous catalyst. Additionally, the catalyst has been implemented in a packed bed reactor with quantitative yield of benzoic acid maintained throughout a two-day run. Biomass derived 5-(hydroxymethyl)furfural (HMF) is also oxidized to 2,5-furandicarboxylic acid (FDCA) in high yield. Exploration of PBT/C for the oxidative methyl esterification was found to exhibit exquisite selectivity for the initial oxidation of primary alcohol instead of methanol, which is the bulk solvent. We explored this selectivity and conclude that it results from various substrate-surface interactions, which are not attainable by methanol. The primary alcohol can outcompete the methanol for binding on the catalyst surface through various interactions between the side chain of the alcohol solvent and the surface of the catalyst: (listed in order of strength) lone pair-surface (heterocyclic primary alcohols)> [pi]-surface (aryl primary alcohols)> van der Waals-surface (alkyl primary alcohols). These interactions were previously underappreciated in condensed phase heterogeneously catalyzed aerobic oxidations. Bi and Te serve as synergistic promoters that enhance both the rate and yield of the reactions relative to reactions employing Pd alone or Pd in combination with Bi or with Te as the sole promoter. We report X-ray absorption spectroscopic studies of the heterogenous catalyst. These methods show that the promoters undergo oxidation in preference to Pd, maintaining the Pd surface in the active metallic state and preventing inhibition by surface Pd-oxide formation. The data also suggest formation of a Pd-Te alloy phase that modifies the electronic properties of the Pd catalyst. Collectively, these results provide valuable insights into the synergistic benefits of multiple promoters in heterogeneous catalytic oxidation reactions.
Download or read book Liquid Phase Oxidation via Heterogeneous Catalysis written by Mario G. Clerici and published by John Wiley & Sons. This book was released on 2013-04-26 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sets the stage for environmentally friendly industrial organic syntheses From basic principles to new and emerging industrial applications, this book offers comprehensive coverage of heterogeneous liquid-phase selective oxidation catalysis. It fully examines the synthesis, characterization, and application of catalytic materials for environmentally friendly organic syntheses. Readers will find coverage of all the important classes of catalysts, with an emphasis on their stability and reusability. Liquid Phase Oxidation via Heterogeneous Catalysis features contributions from an international team of leading chemists representing both industry and academia. The book begins with a chapter on environmentally benign oxidants and then covers: Selective oxidations catalyzed by TS-1 and other metal-substituted zeolites Selective catalytic oxidation over ordered nanoporous metallo-aluminophosphates Selective oxidations catalyzed by mesoporous metal-silicates Liquid phase oxidation of organic compounds by supported metal-based catalysts Selective liquid phase oxidations in the presence of supported polyoxometalates Selective oxidations catalyzed by supported metal complexes Liquid phase oxidation of organic compounds by metal-organic frameworks Heterogeneous photocatalysis for selective oxidations with molecular oxygen All the chapters dedicated to specific types of catalysts follow a similar organization and structure, making it easy to compare the advantages and disadvantages of different catalysts. The final chapter examines the latest industrial applications, such as the production of catechol and hydroquinone, cyclohexanone oxime, and propylene oxide. With its unique focus on liquid phase heterogeneous oxidation catalysis, this book enables researchers in organic synthesis and oxidation catalysis to explore and develop promising new catalytic materials and synthetic routes for a broad range of industrial applications.
Download or read book Methods for Oxidation of Organic Compounds V2 written by Alan Haines and published by Elsevier. This book was released on 2012-12-02 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for the Oxidation of Organic Compounds: Alcohols, Alcohol Derivatives, Alkyl Halides, Nitroalkanes, Alkyl Azides, Carbonyl Compounds, Hydroxyarenes and Aminoarenes describes the different methods used for the controlled oxidation of alcohols, alcohol derivatives, alkyl halides, nitroalkanes, alkyl azides, carbonyl compounds, hydroxyarenes, and aminoarenes. Most of the oxidative techniques considered are illustrated with detailed experimental procedures taken from the literature. This book is comprised of eight chapters and begins with a discussion on the oxidation of alcohols, with particular emphasis on the formation of carbonyl compounds and carboxylic acids. The following chapters focus on the oxidation of esters and alkyl halides; ethers, acetals, and metal derivatives of alcohols; amines, nitro compounds, and azides; carbonyl compounds; 1,2-diols and related compounds; and hydroxyarenes, aminoarenes, dihydroxyarenes, diaminoarenes, and aminohydroxyarenes. Methods such as catalytic oxidation, catalytic dehydrogenation, and electrochemical and biochemical oxidation are mentioned. This monograph should be of interest to organic chemists and research students.
Download or read book Advanced Nanomaterials for Catalysis and Energy written by Vladislav A. Sadykov and published by Elsevier. This book was released on 2018-08-27 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Nanomaterials for Catalysis and Energy: Synthesis, Characterization and Applications outlines new approaches to the synthesis of nanomaterials (synthesis in flow conditions, laser electrodispersion of single metals or alloys on carbon or oxide supports, mechanochemistry, sol-gel routes, etc.) to provide systems with a narrow particle size distribution, controlled metal-support interaction and nanocomposites with uniform spatial distribution of domains of different phases, even in dense sintered materials. Methods for characterization of real structure and surface properties of nanomaterials are discussed, including synchrotron radiation diffraction and X-ray photoelectron spectroscopy studies, neutronography, transmission/scanning electron microscopy with elemental analysis, and more. The book covers the effect of nanosystems' composition, bulk and surface properties, metal-support interaction, particle size and morphology, deposition density, etc. on their functional properties (transport features, catalytic activity and reaction mechanism). Finally, it includes examples of various developed nanostructured solid electrolytes and mixed ionic-electronic conductors as materials in solid oxide fuel cells and asymmetric supported membranes for oxygen and hydrogen separation. Outlines synthetic and characterization methods for nanocatalysts Relates nanocatalysts' properties to their specific applications Proposes optimization methods aiming at specific applications
