Download or read book Sum Frequency Generation SFQ Vibrational Spectroscopy Studies of Combustion Reactions on Platinum Single Crystal Surfaces written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have studied the dissociation of CO catalyzed by platinum single crystals. At 40 torr of CO, the Pt(111) crystal dissociates CO at 673 K. Under the same conditions, Pt(100) dissociates CO at 500 K, and Pt(557) dissociates CO at 548 K. Hence, the CO dissociation reaction is a structure sensitive reaction. SFG was used to monitor the CO top site resonance as the platinum crystals were heated to the dissociation temperature when exposed to 40 torr of CO. In all three systems, the CO resonance shifts to lower frequency as the platinum crystal is heated. However, the frequency of the CO resonance at the dissociation frequency is lower on the (100) and (111) crystal faces than on the Pt(557) crystal. We believe that the (111) and (100) crystal faces must undergo roughening to expose step or kink sites in order to facilitate the dissociation reaction. This is supported by UHV studies of CO dissociation catalyzed by platinum crystals. These studies observe dissociation only when step or kink sites are present. Since the Pt(111) surface is very stable, it needs to be heated to 673 K to produce the low coordination number sites needed for CO dissociation. Since the Pt(100) surface easily reconstructs, it is able to form the active sites for CO dissociation at relatively low temperatures. The SFG spectra support our conclusion that the CO molecules are sitting on low coordination number platinum atoms at the dissociation temperature. Since the Pt(557) surface already has step sites, the dissociation reaction can take place without further roughening of the surface. The CO resonance on the (557) crystal face at the dissociation temperature is at a very similar frequency to CO molecules adsorbed on only the step sites of the crystal. Further studies showed that the dissociation reaction takes place on the (557) surface at CO pressures as low as 1 torr. At 1 torr of CO, the carbon deposition rate is 1.0 x 10−2 ML minute−1. A series of experiments at CO pressures ranging from 5 to 20 torr leads to a 0.8 order dependence of the dissociation reaction on CO pressure.
Download or read book Effect of Surface Structure on Catalytic Reactions written by and published by . This book was released on 2001 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the results discussed above, it is clear that Sum Frequency Generation (SFG) is a unique tool that allows the detection of vibrational spectra of adsorbed molecules present on single crystal surfaces under catalytic reaction conditions. Not only is it possible to detect active surface intermediates, it is also possible to detect spectator species which are not responsible for the measured turnover rates. By correlating high-pressure SFG spectra under reaction conditions and gas chromatography (GC) kinetic data, it is possible to determine which species are important under reaction intermediates. Because of the flexibility of this technique for studying surface intermediates, it is possible to determine how the structures of single crystal surfaces affect the observed rates of catalytic reactions. As an example of a structure insensitive reaction, ethylene hydrogenation was explored on both Pt(111) and Pt(100). The rates were determined to be essentially the same. It was observed that both ethylidyne and di-[sigma] bonded ethylene were present on the surface under reaction conditions on both crystals, although in different concentrations. This result shows that these two species are not responsible for the measured turnover rate, as it would be expected that one of the two crystals would be more active than the other, since the concentration of the surface intermediate would be different on the two crystals. The most likely active intermediates are weakly adsorbed molecules such as [pi]-bonded ethylene and ethyl. These species are not easily detected because their concentration lies at the detection limit of SFG. The SFG spectra and GC data essentially show that ethylene hydrogenation is structure insensitive for Pt(111) and Pt(100). SFG has proven to be a unique and excellent technique for studying adsorbed species on single crystal surfaces under high-pressure catalytic reactions. Coupled with kinetic data obtained from gas chromatography measurements, it can give much insight into how the structure of a single crystal surface affects the chemistry of a catalytic reaction by detecting surface species under reaction conditions.
Download or read book Sum Frequency Generation Vibrational Spectroscopy of Pyridine Hydrogenation on Platinum Nanoparticles written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyridine hydrogenation in the presence of a surface monolayer consisting of cubic Pt nanoparticles stabilized by tetradecyltrimethylammonium bromide (TTAB) was investigated by sum frequency generation (SFG) vibrational spectroscopy using total internal reflection (TIR) geometry. TIR-SFG spectra analysis revealed that a pyridinium cation (C5H5NH) forms during pyridine hydrogenation on the Pt nanoparticle surface, and the NH group in the C5H5NH cation becomes more hydrogen bound with the increase of the temperature. In addition, the surface coverage of the cation decreases with the increase of the temperature. An important contribution of this study is the in situ identification of reaction intermediates adsorbed on the Pt nanoparticle monolayer during pyridine hydrogenation.
Download or read book March s Advanced Organic Chemistry written by Michael B. Smith and published by John Wiley & Sons. This book was released on 2007-01-29 with total page 2379 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sixth Edition of a classic in organic chemistry continues its tradition of excellence Now in its sixth edition, March's Advanced Organic Chemistry remains the gold standard in organic chemistry. Throughout its six editions, students and chemists from around the world have relied on it as an essential resource for planning and executing synthetic reactions. The Sixth Edition brings the text completely current with the most recent organic reactions. In addition, the references have been updated to enable readers to find the latest primary and review literature with ease. New features include: More than 25,000 references to the literature to facilitate further research Revised mechanisms, where required, that explain concepts in clear modern terms Revisions and updates to each chapter to bring them all fully up to date with the latest reactions and discoveries A revised Appendix B to facilitate correlating chapter sections with synthetic transformations
Download or read book Electroceramics written by A. J. Moulson and published by John Wiley & Sons. This book was released on 2003-06-27 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electroceramics, Materials, Properties, Applications, Second Edition provides a comprehensive treatment of the many aspects of ceramics and their electrical applications. The fundamentals of how electroceramics function are carefully introduced with their properties and applications also considered. Starting from elementary principles, the physical, chemical and mathematical background of the subject are discussed and wherever appropriate, a strong emphasis is placed on the relationship between microstructire and properties. The Second Edition has been fully revised and updated, building on the foundation of the earlier book to provide a concise text for all those working in the growing field of electroceramics. * fully revised and updated to include the latest technological changes and developments in the field * includes end of chapter problems and an extensive bibliography * an Invaluable text for all Materials Science students. * a useful reference for physicists, chemists and engineers involved in the area of electroceramics.
Download or read book Advanced Organic Chemistry written by Jerry March and published by Wiley-Interscience. This book was released on 1985-03-11 with total page 1346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This survey of advanced chemistry covers virtually all the useful reactions--600 all told--with the scope, limitations, and mechanism of each described in detail. Extensive general sections on the mechanisms of the important reaction types, and five chapters on the structure and stereochemistry of organic compounds and reactive intermediates are included as well. Of the more than 10,000 references included, 5,000 are new in this edition.
Download or read book The Scientific Papers of James Clerk Maxwell written by James Clerk Maxwell and published by . This book was released on 1890 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics and Chemistry of Materials written by Joel I. Gersten and published by Wiley-Interscience. This book was released on 2001-06-25 with total page 864 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive introduction to the structure, properties, and applications of materials This title provides the first unified treatment for the broad subject of materials. Authors Gersten and Smith use a fundamental approach to define the structure and properties of a wide range of solids on the basis of the local chemical bonding and atomic order present in the material. Emphasizing the physical and chemical origins of material properties, the book focuses on the most technologically important materials being utilized and developed by scientists and engineers. Appropriate for use in advanced materials courses, The Physics and Chemistry of Materials provides the background information necessary to assimilate the current academic and patent literature on materials and their applications. Problem sets, illustrations, and helpful tables complete this well-rounded new treatment. Five sections cover these important topics: * Structure of materials, including crystal structure, bonding in solids, diffraction and the reciprocal lattice, and order and disorder in solids * Physical properties of materials, including electrical, thermal, optical, magnetic, and mechanical properties * Classes of materials, including semiconductors, superconductors, magnetic materials, and optical materials in addition to metals, ceramics, polymers, dielectrics, and ferroelectrics * A section on surfaces, thin films, interfaces, and multilayers discusses the effects of spatial discontinuities in the physical and chemical structure of materials * A section on synthesis and processing examines the effects of synthesis on the structure and properties of various materials This book is enhanced by a Web-based supplement that offers advanced material together with an entire electronic chapter on the characterization of materials. The Physics and Chemistry of Materials is a complete introduction to the structure and properties of materials for students and an excellent reference for scientists and engineers.
Download or read book Nano Biophotonics written by Hiroshi Masuhara and published by Elsevier. This book was released on 2007-02-16 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: This third volume in the series represents the Proceedings of the 3rd International Nanophotonics Symposium, July 6-8, 2006, Icho-Kaikan, Osaka University, Osaka, Japan. Over a two-day symposium, distinguished scientists from around the world convened to discuss the latest progress in this field and the conclusions have been summarised in Nano Biophotonics: Science and Technology. The contents of this book have been compiled by invited lecturers, research members of the relevant projects/program, and some of general participants. The book has 27 chapters which are classified into 4 parts; nano bio-spectroscopy, nano bio-dynamics, nano bio-processing, and nano bio-devices.* Bridges the gap between conventional photophysics & photochemistry and nanoscience* Continuing the series that focuses on 'hot' areas of photochemistry, optics, material science and bioscience
Download or read book A Comprehensive English Hindi Dictionary written by Raghu Vira and published by . This book was released on 2009 with total page 755 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supplementary volume to Comprehensive English-Hindi dictionary of governmental & educational words & phrases--.
Download or read book Atomic and Nanoscale Magnetism written by Roland Wiesendanger and published by Springer. This book was released on 2018-11-02 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of the fascinating recent developments in atomic- and nanoscale magnetism, including the physics of individual magnetic adatoms and single spins, the synthesis of molecular magnets for spintronic applications, and the magnetic properties of small clusters as well as non-collinear spin textures, such as spin spirals and magnetic skyrmions in ultrathin films and nanostructures. Starting from the level of atomic-scale magnetic interactions, the book addresses the emergence of many-body states in quantum magnetism and complex spin states resulting from the competition of such interactions, both experimentally and theoretically. It also introduces novel microscopic and spectroscopic techniques to reveal the exciting physics of magnetic adatom arrays and nanostructures at ultimate spatial and temporal resolution and demonstrates their applications using various insightful examples. The book is intended for researchers and graduate students interested in recent developments of one of the most fascinating fields of condensed matter physics.
Download or read book Nanotechnology Challenges written by Joachim Schummer and published by World Scientific. This book was released on 2006 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the latest methods for the controlled growth of nanomaterial systems. The coverage includes simple and complex nanomaterial systems, ordered nanostructures and complex nanostructure arrays, and the essential conditions for the controlled growth of nanostructures with different morphologies, sizes, compositions, and microstructures. The book also discusses the dynamics of controlled growth and thermodynamic characteristics of two-dimensional nanorestricted systems. The authors introduce various novel synthesis methods for nanomaterials and nanostructures, such as hierarchical growth, heterostructures growth, doping growth and some developing template synthesis methods. In addition to discussing applications, the book reviews developing trends in nanomaterials and nanostructures.
Download or read book Device Applications of Nonlinear Dynamics written by Salvatore Baglio and published by Springer. This book was released on 2010-11-20 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is devoted to applications of complex nonlinear dynamic phenomena to real systems and device applications. In recent decades there has been significant progress in the theory of nonlinear phenomena, but there are comparatively few devices that actually take this rich behavior into account. The text applies and exploits this knowledge to propose devices which operate more efficiently and cheaply, while affording the promise of much better performance.
Download or read book Motor Gasolines written by and published by . This book was released on 1975 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Nano written by Amretashis Sengupta and published by Springer. This book was released on 2015-07-01 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the basics of nanotechnology and provides a solid understanding of the subject. Starting from a brush-up of the basic quantum mechanics and materials science, the book helps to gradually build up understanding of the various effects of quantum confinement, optical-electronic properties of nanoparticles and major nanomaterials. The book covers the various physical, chemical and hybrid methods of nanomaterial synthesis and nanofabrication as well as advanced characterization techniques. It includes chapters on the various applications of nanoscience and nanotechnology. It is written in a simple form, making it useful for students of physical and material sciences.
Download or read book Appendices B C and D written by United States. Congress. Senate. Committee on Labor and Public Welfare. Subcommittee on Labor and published by . This book was released on 1972 with total page 1388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatty Acid and Lipid Chemistry written by F.D. Gunstone and published by Springer. This book was released on 2012-12-06 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has a pedigree. It has developed from earlier publications by the author and from his experience over 50 years in reading, writing, thinking, and working with lipids and fatty acids. The earlier publications are: (i) An Introduction to the Chemistry of Fats and Fatty Acids, Chapman and Hall, 1958. (ii) An Introduction to the Chemistry and Biochemistry of Fatty Acids and their Glycerides, Chapman and Hall, 1967. (iii) Lipids in Foods: Chemistry, Biochemistry, and Technology (with F. A. Norris), Pergamon Press, 1983. (iv) The Lipid Handbook (with J. L. Harwood and F. B. Padley), Chapman and Hall, first edition 1986, second edition 1994. (v) A Lipid Glossary (with B. G. Herslof), The Oily Press, Dundee, 1992. (vi) Lecture notes for a course on Fatty Acids and Lipids designed for those entering the oil and fat industry and given on over 20 occasions since 1977. The book is dedicated to the next generation of lipid scientists. The study of lipids now involves many disciplines, all of which require a basic knowledge of the chemical nature and properties of these molecules, which is what this book is about. It is written particularly for those who, with some knowledge of chemistry or biochemistry, need to know more about the nature of lipids and fatty acids.
