Download or read book Theoretical Studies of Chemisorption on Semiconductor and Transition Metal Surfaces written by Ze Jing and published by . This book was released on 1991 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies of Chemisorption on Transition Metal Surfaces written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemisorption of molecules on solid surfaces, the development of a general formalism, and specific applications to the hydrogen-titanium system were studied. For H2 on Ti, the goal is a determination of the energetics of adsorption and molecular dissociation as a function of surface site and a general description of bonding in the surface region including the response of the lattice to the absorbate. (FS).
Download or read book Theoretical Studies of Chemisorption on Transition metal Surfaces written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research concerns the theory of chemisorption of molecules on solid surfaces: the development of a general formalism, and specific applications to the hydrogen-titanium system. The objective is to develop a suitable formalism for treating electronic interactions at an ab initio level when both localized and delocalized interactions occur, as in the case of molecular adsorption on a metallic surface. For H2 and CO adsorption on titanium, the goal is a determination of the energetics of adsorption and molecular dissociation as a function of surface site. The first phase of the research concerned primarily the formalism and the second the modeling of the titanium surface, preparatory to the chemisorption studies. The final phase of the research has dealt with applications of the chemisorption theory to several systems: H2 on Ti(0001), CO on Ti(0001), interstitial H in titanium, H on Cu(100) and H2 dissociation on Cu(100). Work on stepped copper surfaces and CO interactions with Ni(100) was also begun. With the exception of the latter two projects now underway, the results of all studies have been published. Brief summaries of the individual projects are included in this report.
Download or read book Chemisorption and Reactivity on Supported Clusters and Thin Films written by R.M. Lambert and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterogeneous catalysis provides the backbone of the world's chemical and oil industries. The innate complexity of practical catalytic systems suggests that useful progress should be achievable by investigating key aspects of catalysis by experimental studies on idealised model systems. Thin films and supported clusters are two promising types of model system that can be used for this purpose, since they mimic important aspects of the properties of practical dispersed catalysts. Similarly, appropriate theoretical studies of chemisorption and surface reaction clusters or extended slab systems can provide valuable information on the factors that underlie bonding and catalytic activity. This volume describes such experimental and theoretical approaches to the surface chemistry and catalytic behaviour of metals, metal oxides and metal/metal oxide systems. An introduction to the principles and main themes of heterogeneous catalysis is followed by detailed accounts of the application of modern experimental and theoretical techniques to fundamental problems. The application of advanced experimental methods is complemented by a full description of theoretical procedures, including Hartree-Fock, density functional and similar techniques. The relative merits of the various approaches are considered and directions for future progress are indicated.
Download or read book Theoretical Studies of Chemisorption on Transition Metal Surfaces written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research is concerned with the theory of chemisorption of molecules on solid surfaces, with applications to the hydrogen-titanium system. The ab initio computational formulation is based on two main ideas: (1) the application of a recently developed approximation technique which utilizes error bounds on electrostatic interactions to achieve a major organizational simplification of the problem, and (2) the definition of a local (surface) region plus the adsorbate in which the partitioning is accomplished by an orbital localization scheme. The first phase of research was concerned primarily with the implementation of basic computational techniques including the approximation of electrostatic interactions, development of multipole expansions, and the direct approximation of the electron density and first order density matrix derived from a given wavefunction based on error bound criteria. A pseudopotential method was developed for the approximation of atomic cores. Calculations on Ti atom, TiH, Ti/sub n/-linear (n = 1-10), Ti9-planar, and Ti9H systems were carried out to test the computational methods and to examine the concept of a local (surface) region defined by the localization transformation. In all linear chain and Ti9-planar cases, the exchange maximization with a designated site gave well localized orbitals, and in the linear chains, the localized orbitals were found to be invariant for n greater than or equal to 4.
Download or read book Theory of Chemisorption written by J. R. Smith and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory of the chemical interaction of molecules with surfaces has advanced handsomely in the last few years. This is due in part to the application of the entire arsenal of bulk solid-state theory and molecular quantum chemistry methods. This considerable activity was stimulated by an outpouring of experimental data, particularly of photoemission spectra. In many cases the theoretical techniques are now such that accurate, atomistic pictures of chemisorption phenomena are computed from first principles. This level of capability has been reached only recently, and has not been described anywhere in a comprehensive manner. The purpose of this monograph is to review these recent advances and, at the same time, to indicate a number of important questions which have not been answered. We discuss chemisorption on oxides, semiconductors, and both simple and transition metals. Solid surfaces as well as clusters are considered. While the review should be valuable to workers in the field, care has been taken to make the chapters understandable to the nonspecialist.
Download or read book A theoretical study of chemisorption and reactions on transition metal surfaces written by Anton Kokalj and published by . This book was released on 2000 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Chemistry Approaches to Chemisorption and Heterogeneous Catalysis written by F. Ruette and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of "high-tech" materials in contemporary industries is deeply related to a detailed understanding of specific surface properties of catalysts which make particular reactions possible. But this understanding presupposes that there exists a body of theory capable of explaining situations not easily accessible to experimental methods and of relating experimental findings among themselves and with theoretical constructs. For these reasons, theoretical developments in surface physics and surface chemistry of transition metal compounds have been of paramount importance in promoting progress in catalysis, electronic devices, corrosion, etc. Although a great variety of spectroscopic methods for analyzing solids and surfaces at molecular scale have been introduced in recent years, nevertheless, many questions about the adsorption sites and intermediates, the effect of promoters, the poisoning of active sites, the nature of segregation of impurities, the process of surface reconstruction, the mechanisms of reactions, etc. have remained unanswered simply because of the great complexity of surface phenomena. It is in this sense that quantum mechanical method- combined with experimental data - may shed some light on the microscopic properties of new surface materials.
Download or read book Chemisorption on Transition Metal Surfaces written by Flavio Favot and published by . This book was released on 2001 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies of Chemisorption and Surface Reactions on Nickel and Silicon written by and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research is part of a theoretical program on the structure of molecules adsorbed on solid surfaces and dissociative chemisorption which emphasis on transition metal substrates and electronic materials. An embedding theory for treating chemisorption on metals is further developed and applied to the reaction of hydrocarbon fragments and hydrogen coadsorbed on nickel, the dissociation of water on nickel, and the system H/Ni, NH3/Ni, and C6H6/Ni. The main emphasis of the work is on the energetics of adsorption as a function of surface site, the potential energy for adsorbate motion between surface sites and the energetics of surface reactions. Equilibrium geometries, vibrational frequencies and ionization potentials are also calculated. Preliminary work on the description of Si(100) surfaces has been completed in preparation of H/Si and N/Si adsorption studies. Studies of [pi] bonding on Si(111) were also completed and work was begun on the Auger ionization of F/Si. The original form of the embedding theory has been extended to make use of an effective potential representation of the bulk electrons interacting with the embedded surface region. Effective core potentials for Fe have been developed.
Download or read book Theoretical Studies of Transition Metal Complexes and Surfaces written by Shen-Shu Sung and published by . This book was released on 1984 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Structure and Reactivity of Metal Surfaces written by E. Derouane and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Imagine that a young physicist would approach a granting agen cy and propose to contribute to heterogeneous catalysis by studying the heat conductivity of gases in contact with a hot filament. How would he be received now? How would he have been treated sixty years ago ? Yet, more than sixty years ago, Irving Langmuir, through his study of heat transfer from a tungsten filament, uncovered most of the fundamental ideas which are used to-day by the scientific com munity in pure and applied heterogeneous catalysis. Through his work with what were for the first time "clean" metal surfaces, Langmuir formulated during a period of a little over ten years un til the early thirties, the concepts of chemisorption, monolayer, adsorption sites, adsorption isotherm, sticking probability, cata lytic mechanisms by way of the interaction between chemisorbed spe cies, behavior of non-uniform surfaces and repulsion between adsor bed dipoles. It is fair to say that many of these ideas constituting the first revolution in surface chemistry have since been refined through thousands of investigations. Countless papers have been pu blished on the subject of the Langmuir adsorption isotherm, the Langmuir catalytic kinetics and the Langmuir site-exclusion adsorp tion kinetics. The refinements have been significant. ThE original concepts in their primitive or amended form are used everyday by catalytic chemists and chemical engineers allover the world in their treatment of experimental data, design of reactors or inven tion of new processes.
Download or read book Theroretical Studies of Chemisorption on Transition Metal Surfaces written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory of chemisorption of molecules on solid surfaces, including the development of a general formalism and specific applications to the hydrogen-titanium system are described. The objective is to develop a suitable formalism for treating electronic interactions at an ab initio level when both localized and delocalized interactions occur, as in the case of molecular adsorption on a metallic surface. For H2 on titanium, the goal is a determination of the energetics of adsorption and molecular dissociation as a function of surface site. The first phase of the research concerned primarily the formalism and the second, the modeling of the titanium surface, preparatory to the chemisorption studies. To investigate surface models, SCF calculations on Ti10 at Ti30 closed packed sheets and a Ti54 three layer model were used. A key element of the theory is the partitioning of the lattice wave-function into localized surface components and an interior region and such localizations were examined for the Ti10, Ti30 and Ti54 models. In addition questions concerning the extent of d orbital localization were investigated on linear chains of Ti atoms and results were compared with previous ab initio SCF calculations. Preliminary calculations of H2 on a 10-atom Ti monolayer are also reported.
Download or read book Theoretical Studies of Metal Chemisorption on Silicon 001 and 111 Surfaces written by Hong-Qing Shi and published by . This book was released on 2004 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemisorption And Reactions On Metallic Films V2 written by J Anderson and published by Elsevier. This book was released on 2012-12-02 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemisorption and Reactions on Metallic Films, Volume 2 is a four-chapter text that describes the role of evaporated metal films in advancing the understanding of the metal-gas interface chemistry and in understanding of adsorption and catalysis at metal surfaces. This volume first describes film structure and properties, particularly of random polycrystalline films, as well as the concepts of the adsorption and kinetic phenomena. The topic is followed by an overview of the main classes of catalytic reactions that have been studied over evaporated metal film catalysts. A chapter explores the preparation, characterization, structure, and surface properties of alloy films. The theory of the oxidation of metals and the advantages and disadvantages of using thin metal films in oxidation work are considered in the concluding chapter, along with a brief discussion on their use in kinetic and mechanistic studies. Research scientists and graduate students who are interested in the fundamentals of adsorption and catalysis will find this volume invaluable.
Download or read book The Chemisorptive Bond written by Alfred Clark and published by Elsevier. This book was released on 2012-12-02 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Chemisorptive Bond: Basic Concepts describes the basic concepts of the chemisorptive bond on solid surfaces from the simple analogies with ordinary chemical bonds to the quantum-mechanical approaches. This book is composed of 10 chapters and begins with discussions of simple formulas for correlating measurable quantities in chemisorptions and catalysis. The succeeding chapters deal with theories based on quantum-mechanical principles that describe the mutual interactions of atoms of the solid and foreign atoms on the surface. The remaining chapters consider the possible arrangements of ligands about a central metal atom, including octahedral, tetrahedral, cubic, and square planar, and how these arrangements affect chemisorption. This book will be of great value to chemical engineers and researchers.
Download or read book Metal Ligand Interactions From Atoms to Clusters to Surfaces written by Dennis R. Salahub and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal-ligand interactions are currently being studied in different fields, from a variety of points of view, and recent progress has been substantial. Whole new classes of compounds and reactions have been found; an arsenal of physical methods has been developed; mechanistic detail can be ascertained to an increasingly minute degree; and the theory is being developed to handle systems of ever-growing complexity. As usual, such multidisciplinarity leads to great opportunities, coupled with great problems of communication between specialists. It is in its promotion of interactions across these fields that Metal-Ligand Interactions: From Atoms, to Clusters, to Surfaces makes its timely contribution: the tools, both theoretical and experimental, are highly developed, and fundamental questions remain unanswered. The most fundamental of these concerns the nature of the microscopic interactions between metal atoms (clusters, surfaces) and ligands (atoms, molecules, absorbates, reagents, products) and the changes in these interactions during physical and chemical transformation. In Metal-Ligand Interactions, leading experts discuss the following, vital aspects: ab initio theory, semi-empirical theory, density functional theory, complexes and clusters, surfaces, and catalysis.
