Download or read book Direct Synthesis of Hydrogen Peroxide from Hydrogen and Oxygen Over Catalysts Containing Gold written by Jennifer Kelly Edwards and published by . This book was released on 2006 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Direct Synthesis of Hydrogen Peroxide Using Bimetallic Gold and Palladium Supported Catalysts written by Greg Shaw and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis the direct synthesis of hydrogen peroxide from hydrogen and oxygen using gold-palladium supported catalysts is described. The direct route presents a greener and sustainable alternative to the current industrial manufacture process. This work aims to meet industrial requirements set by Solvay® which would make the direct process industrially viable. The drawback preventing the requirements being met is the reaction of hydrogen and oxygen over a catalyst can yield water as well as hydrogen peroxide. Once H2O2 is formed, it can be consumed by either reduction or decomposition. Thus, the rates of the subsequent reactions must be minimized to increase the selectivity and therefore H2O2 concentration to a desirable level. Aspects of the catalyst design and reaction variables have been studied over three results chapters. Firstly, the thermal treatment conditions have been altered, ultimately producing a catalyst with no activity to the H2O2 consumption under standard conditions. Switching off H2O2 hydrogenation was concluded to be due to an increase in Pd2+, isolating active Pd0 species. Secondly, active catalysts to both the synthesis and hydrogenation of H2O2 have been produced with no halide; the addition of halide has been shown to decrease hydrogenation activity while maintaining synthesis activity. Finally, a biphasic solvent system and a constant flow of gases through the reaction medium have been examined in order to produce higher H2O2 concentrations. In the former case H2O2 is extracted in-situ from an immiscible organic phase. The production of a 3 wt% H2O2 solution highlights the potential of such a system. In the latter case a semi-continuous flow reactor is utilised increasing the H2O2 concentration up to ca. 1 wt% (from ca. 0.2 wt%). The reactor allowed H2 selectivity and H2O concentration to be measured as a function of time, thus providing greater insight into catalyst activity.
Download or read book Investigations Into the Direct Synthesis of Hydrogen Peroxide and CO Oxidation Using Precious Metal Catalysts written by Simon James Freakley and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The direct synthesis of hydrogen peroxide from molecular hydrogen and oxygen represents an attractive atom efficient alternative to the current industrial auto-oxidation process which relies on the sequential oxidation and reduction of an anthraquinone. The first and most widely studied catalysts for this reaction were palladium based however over-hydrogenation of the synthesised hydrogen peroxide is a problem. Recent advances demonstrate that the addition of gold to the catalyst has been shown to significantly improve the productivity of the catalysts by suppressing the hydrogenation and decomposition activity. The work in this thesis shows that tin can be used as a catalyst additive as a direct replacement for gold by a simple impregnation method. By tuning the heat treatments of these bimetallic tin-palladium catalysts it was possible to switch off the competing hydrogenation and decomposition reactions. The construction of a small scale flow system has allowed the independent study of reaction variables and the determination of global kinetics and rate constants for the synthesis and subsequent reactions. It was shown that in a flow system it was the decomposition reaction that had a greater limiting effect on the production of hydrogen peroxide than the hydrogenation reaction. A study was also carried out into CO oxidation using gold / iron oxide catalyst prepared in Cardiff and by Prof. Haruta's group in Tokyo. These catalysts underwent extensive tests to try and identify the active species of the catalyst. Detailed testing and STEM characterisation of the samples identified the possibility of different mechanisms operating at different temperatures and no correlation between the nanoparticle population and activity at sub ambient temperature could be made which challenges the hypothesis that nanoparticles are the most active species and that sub nanometer clusters may be the active species at low temperatures.
Download or read book The Direct Synthesis of Hydrogen Peroxide Using Gold and Palladium Based Catalysts written by Marco Piccinini and published by . This book was released on 2012 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book XAFS Techniques for Catalysts Nanomaterials and Surfaces written by Yasuhiro Iwasawa and published by Springer. This book was released on 2016-10-19 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive, theoretical, practical, and thorough guide to XAFS spectroscopy. The book addresses XAFS fundamentals such as experiments, theory and data analysis, advanced XAFS methods such as operando XAFS, time-resolved XAFS, spatially resolved XAFS, total-reflection XAFS, high energy resolution XAFS, and practical applications to a variety of catalysts, nanomaterials and surfaces. This book is accessible to a broad audience in academia and industry, and will be a useful guide for researchers entering the subject and graduate students in a wide variety of disciplines.
Download or read book The Direct Synthesis of Hydrogen Peroxide Using Bimetallic Gold and Palladium Supported Catalysts written by Adeeba Akram 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 Kinetics of Heterogeneous Catalytic Reactions written by Michel Boudart and published by Princeton University Press. This book was released on 2014-07-14 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
Download or read book Towards On site Production of Hydrogen Peroxide with Gold palladium Catalysts in Electrocatalysis and Heterogeneous Catalysis written by Enrico Pizzutilo and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of Heterogeneous Catalysts written by Francis Delannay and published by Marcel Dekker. This book was released on 1984 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The 100 Most Important Chemical Compounds written by Richard L. Myers and published by Bloomsbury Publishing USA. This book was released on 2007-08-30 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is a chemical compound? Compounds are substances that are two or more elements combined together chemically in a standard proportion by weight. Compounds are all around us - they include familiar things, such as water, and more esoteric substances, such as triuranium octaoxide, the most commonly occurring natural source for uranium. This reference guide gives us a tour of 100 of the most important, common, unusual, and intriguing compounds known to science. Each entry gives an extensive explanation of the composition, molecular formula, and chemical properties of the compound. In addition, each entry reviews the relevant chemistry, history, and uses of the compound, with discussions of the origin of the compound's name, the discovery or first synthesis of the compound, production statistics, and uses of the compound.
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 Mechanisms Active Sites and Promoters for the Direct Synthesis of Hydrogen Peroxide on Pd based Catalysts written by Anthony David Plauck and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The widespread use of hydrogen peroxide (H2O2) for catalytic oxidations is limited by the wasteful process by which it is currently produced: the anthraquinone process. The direct synthesis of H2O2 (DSHP) is a promising alternative process. One primary technical obstacle to its commercialization is the identification of sufficiently active and selective heterogeneous catalysts. Although Pd is a promising active component that is used in most catalyst formulations, two factors have restricted the search directions for improved DSHP catalysts to experimental trial and error: (i) the reaction mechanisms are not resolved, and (ii) the active site requirements are poorly understood. Addressing these factors is complicated by the existence of multiple side reactions and the inherent complexities of heterogeneous catalysts and the DSHP reaction environment. In this dissertation, we employ density functional theory calculations to develop an atomic-scale understanding of the DSHP on Pd-based catalysts. We propose reaction mechanisms and analyze Pd's intrinsic reactivity toward forming H2O2 versus H2O from H2 and O2. We also develop an experimentally-consistent microkinetic model that describes H2O2 decomposition on Pd; one of the major drawbacks of Pd catalysts is high activity toward this undesirable reaction. Through these studies we highlight specific mechanistic challenges, including the identification of likely rate-limiting steps. We then consider how catalyst structure and composition can be modified to mitigate these challenges. We analyze the impact of the coordinative saturation of the Pd surface, the role of halides and Au as catalytic promoters, and the effect of phase transformations induced by the reaction environment. Our work demonstrates the utility of computational chemistry in deconvoluting complex catalytic systems - especially when coupled with experimental and microkinetic analyses. The results can potentially be used to build a framework that guides the search for new DSHP catalysts.
Download or read book Applications of Hydrogen Peroxide and Derivatives written by C W Jones and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Simple, but beautifully versatile. Perhaps not a description many would choose for hydrogen peroxide, but an accurate one none the less, and this unique book explains the reasons behind the description. Beginning with an historical overview, and guidelines for the safe handling of peroxygens, Applications of Hydrogen Peroxide and Derivatives goes on to cover key activation mechanisms, organic functional group oxidations and the use of hydrogen peroxide with heterogeneous catalysts. The clean-up of environmental pollutants; chemical purification; and extraction of metals from their ores are also discussed in detail, using actual examples from industry. The versatility of this reagent may well prove to be a key to integrated pollution control in the future. This book should therefore be read by academics and industrialists at all levels, to encourage wider applications of the use of hydrogen peroxide in laboratories.
Download or read book Modern Physical Organic Chemistry written by Eric V. Anslyn and published by University Science Books. This book was released on 2006 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt: In additionto covering thoroughly the core areas of physical organic chemistry -structure and mechanism - this book will escortthe practitioner of organic chemistry into a field that has been thoroughlyupdated.
Download or read book New Catalysts for the Direct Synthesis of Hydrogen Peroxide written by Stefano Melada and published by . This book was released on 2005 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalysis By Gold written by Geoffrey C Bond and published by World Scientific. This book was released on 2006-08-15 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold has traditionally been regarded as inactive as a catalytic metal. However, the advent of nanoparticulate gold on high surface area oxide supports has demonstrated its high catalytic activity in many chemical reactions. Gold is active as a heterogeneous catalyst in both gas and liquid phases, and complexes catalyse reactions homogeneously in solution. Many of the reactions being studied will lead to new application areas for catalysis by gold in pollution control, chemical processing, sensors and fuel cell technology. This book describes the properties of gold, the methods for preparing gold catalysts and ways to characterise and use them effectively in reactions. The reaction mechanisms and reasons for the high activities are discussed and the applications for gold catalysis considered./a
Download or read book Direct Synthesis of Hydrogen Peroxide Using Monometallic and Bimetallic Pd Based Catalysts Supported on TiO2 written by Dávid Kovačič and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
