Poisoning and promotion in catalysis based on surface science concepts and experiments PDF Download

Author: MP. Kiskinova
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: M.P. Kiskinova
Publisher: Elsevier
ISBN: 0080887406
Category : Technology & Engineering
Languages : en
Pages : 359

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Book Description
The topics covered in this book include a variety of adsorption and model reaction studies on clean and modified single crystal metal surfaces obtained by means of properly selected surface sensitive techniques. The accent is on the revelation of the physics and chemistry involved in the effects of various modifiers on the adsorptive and reactivity properties of the surface with respect to different reactants. In this book current information that contributes to the fundamental understanding of the effect of additives is summarized. Some of the additives act as promoters, others as poisons, in a number of important catalytic reactions. A description of single- and double-component systems has been obtained by using surface-sensitive techniques, particularly suited for this purpose. For the benefit of the reader, a short summary of the main surface science techniques has been given in Chapter 2. Three general and interrelated topics are reviewed. The first concerns the interaction of electronegative (Cl, S, Se, C, N, O, P) and electropositive (alkali metals) atoms with metal surfaces (Chapter 4). The second topic covers the chemisorptive properties of metal surfaces modified by varying amounts of additives with respect to different reactants (CO, NO, N2, O2, H2, CO2, NH3, H2O and hydrocarbons) (Chapters 5 and 6). In particular the adsorption kinetics and energetics, and the electronic, structural and reactive properties of the coadsorbate systems are considered, whereby particular attention is given to recent surface science studies with well-characterized, single crystal, metal surfaces. In these chapters, special attention is paid to showing the contribution of different factors (the nature and adsorption state of the modifier and the coadsorbed molecule, the structure of the adsorbed layer, the type of interactions in the mixed overlayers, etc.) to the modifier effects. In the discussion of the third topic, model studies of several important catalytic reactions (Fischer-Tropsch synthesis, ammonia synthesis, CO oxidation, water-gas shift synthesis) on modified metal surfaces (Chapter 8) are considered.The book will be particularly useful to scientists who are interested in adsorption phenomena, surface properties and catalysis. It should also prove invaluable to those addressing the questions of condensed matter (surfaces and interfaces), materials science (e.g. corrosion of metals) and electrochemistry.

Author: Costas G. Vayenas
Publisher: Springer Science & Business Media
ISBN: 0306475510
Category : Science
Languages : en
Pages : 597

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I knew nothing of the work of C. G. Vayenas on NEMCA until the early nineties. Then I learned from a paper of his idea (gas interface reactions could be catalyzed electrochemically), which seemed quite marvelous; but I did not understand how it worked. Consequently, I decided to correspond with Professor Vayenas in Patras, Greece, to reach a better understanding of this concept. I think that my early papers (1946, 1947, and 1957), on the relationship between the work function of metal surfaces and electron transfer reactions thereat to particles in solution, held me in good stead to be receptive to what Vayenas told me. As the electrode potential changes, so of course, does the work function at the interface, and gas metal reactions there involve adsorbed particles which have bonding to the surface. Whether electron transfer is complete in such a case, or whether the effect is on the desorption of radicals, the work function determines the strength of their bonding, and if one varies the work function by varying the electrode potential, one can vary the reaction rate at the interface. I got the idea. After that, it has been smooth sailing. Dr. Vayenas wrote a seminal article in Modern Aspects of Electrochemistry, Number 29, and brought the field into the public eye. It has since grown and its usefulness in chemical catalytic reactions has been demonstrated and verified worldwide.

Author: A. Guerrero-Ruiz
Publisher: Elsevier
ISBN: 0080539742
Category : Technology & Engineering
Languages : en
Pages : 501

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"Spillover and Mobility of Species and Solid Surfaces" collects the papers which were presented at the Fifth International Conference Spillover, either as oral or poster contributions, as well as the summaries of the invited lectures. This congress and its publication in the Studies on Surface Science and Catalysis series follow the tradition of previous conferences on spillover, initiated in Lyon, 1983, and continued in Leipzig, 1989, Kyoto 1993 and Dalian, 1997. For the fifth conference, held in S.L. el Escorial (Madrid), the organising committee has attempted to compile representative contributions which illustrate the advances in understanding the spillover phenomenon since 1997. Spillover is a process taking place during the interface of gas reactant molecules (mainly hydrogen and oxygen) on solid surfaces. However, different contributions to the more general area of the chemistry at surfaces, related with the mobility and migration of species, diffusion through membranes, fuel cell catalysts, etc., have also been included. In fact the title of the present volume summarizes this attempt to extend the conference topics towards dynamics at surfaces.Among the 70 contributions received, the 56 accepted papers were selected on the basis of the reports of at least two international reviewers, according to standards comparable to those applied for other specialised journals. These papers are from 21 different countries.

Author: Gabor A. Somorjai
Publisher: John Wiley & Sons
ISBN: 047050823X
Category : Science
Languages : en
Pages : 804

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Now updated-the current state of development of modern surface science Since the publication of the first edition of this book, molecular surface chemistry and catalysis science have developed rapidly and expanded into fields where atomic scale and molecular information were previously not available. This revised edition of Introduction to Surface Chemistry and Catalysis reflects this increase of information in virtually every chapter. It emphasizes the modern concepts of surface chemistry and catalysis uncovered by breakthroughs in molecular-level studies of surfaces over the past three decades while serving as a reference source for data and concepts related to properties of surfaces and interfaces. The book opens with a brief history of the evolution of surface chemistry and reviews the nature of various surfaces and interfaces encountered in everyday life. New research in two crucial areas-nanomaterials and polymer and biopolymer interfaces-is emphasized, while important applications in tribology and catalysis, producing chemicals and fuels with high turnover and selectivity, are addressed. The basic concepts surrounding various properties of surfaces such as structure, thermodynamics, dynamics, electrical properties, and surface chemical bonds are presented. The techniques of atomic and molecular scale studies of surfaces are listed with references to up-to-date review papers. For advanced readers, this book covers recent developments in in-situ surface analysis such as high- pressure scanning tunneling microscopy, ambient pressure X-ray photoelectron spectroscopy, and sum frequency generation vibrational spectroscopy (SFG). Tables listing surface structures and data summarizing the kinetics of catalytic reactions over metal surfaces are also included. New to this edition: A discussion of new physical and chemical properties of nanoparticles Ways to utilize new surface science techniques to study properties of polymers, reaction intermediates, and mobility of atoms and molecules at surfaces Molecular-level studies on the origin of the selectivity for several catalytic reactions A microscopic understanding of mechanical properties of surfaces Updated tables of experimental data A new chapter on "soft" surfaces, polymers, and biointerfaces Introduction to Surface Chemistry and Catalysis serves as a textbook for undergraduate and graduate students taking advanced courses in physics, chemistry, engineering, and materials science, as well as researchers in surface science, catalysis science, and their applications.

Author: J.M. Berty
Publisher: Elsevier
ISBN: 0080531423
Category : Technology & Engineering
Languages : en
Pages : 289

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The science of catalytic reaction engineering studies the catalyst and the catalytic process in the laboratory in order to predict how they will perform in production-scale reactors. Surprises are to be avoided in the scaleup of industrial processes. The laboratory results must account for flow, heat and mass transfer influences on reaction rate to be useful for scaleup. Calculated performance based on these results must also be useful to maximization of profit and safety and minimization of pollution. To this end, information on products as well as byproducts and heat produced must be generated. If a sufficiently large database of knowledge is produced, optimization studies will be possible later if economic conditions change.The field of reaction engineering required new tools. For kinetic and catalyst testing, the most successful of these tools was the internal recycle reactor. Studies in recycle reactors can be made under well-defined conditions of flow and associated transfer processes, and close to commercial operation. The recycle reactor eliminates or minimizes the effect of transfer process, and allows the remaining ones to be known.Features of this book:• Provides insight into a field that is neither well understood nor properly appreciated.• Gives a deeper understanding of reaction engineering practice.• Helps avoid frustration and disappointment in industrial research. This book is short and clear enough to assist all members of the R&D and Engineering team, whether reaction engineers, or specialists in other fields. This is critical in this new age of computation and communication, when team members must each know at least something of their colleagues' fields. Additionally, many scientists in more exploratory or fundamental fields can use recycle reactors to study basic phenomena free of transfer interactions.

Author: Andrzej Wieckowski
Publisher: CRC Press
ISBN: 0203912713
Category : Science
Languages : en
Pages : 970

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Book Description
Illustrating developments in electrochemical nanotechnology, heterogeneous catalysis, surface science and theoretical modelling, this reference describes the manipulation, characterization, control, and application of nanoparticles for enhanced catalytic activity and selectivity. It also offers experimental and synthetic strategies in nanoscale surface science. This standard-setting work clariefies several practical methods used to control the size, shape, crystal structure, and composition of nanoparticles; simulate metal-support interactions; predict nanoparticle behavior; enhance catalytic rates in gas phases; and examine catalytic functions on wet and dry surfaces.

Author: Spyridon Zafeiratos
Publisher: World Scientific
ISBN: 180061330X
Category : Science
Languages : en
Pages : 548

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Book Description
X-ray photoelectron spectroscopy (XPS) has become a standard practice technique, and automated XPS facilities can be found in industry and in universities all over the world. This transformed XPS from an advanced characterization method for dedicated research, to a rather standard analysis technique of surface analysis. The catalyst's surface state is probably the most prominent factor that influences the catalytic performance. It is therefore no surprise that XPS has become an indispensable tool in studies of solid catalysts. It has been directly used to investigate issues such as the surface composition of the active catalyst and reaction and deactivation mechanisms.The objective of this book is to provide a comprehensive overview of the current status and future perspectives of X-ray photoelectron spectroscopy dedicated to catalytic applications, including thermal catalysis, electrocatalysis, and photo(electro)catalysis. The book contains 13 chapters, starting with the necessary introduction of the technique background, including basic phenomena and instrumentation aspects. The second part of the book focuses on the presentation of long-established applications of the technique, such as XPS studies of model catalysts. Finally, the book describes relatively recent developments of this method for cutting-edge surface characterization mainly using synchrotron X-ray radiation.

Author: G.F. Froment
Publisher: Elsevier
ISBN: 0080530621
Category : Technology & Engineering
Languages : en
Pages : 611

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Many processes of the chemical industry are based upon heterogeneous catalysis. Two important items of these processes are the development of the catalyst itself and the design and optimization of the reactor. Both aspects would benefit from rigorous and accurate kinetic modeling, based upon information on the working catalyst gained from classical steady state experimentation, but also from studies using surface science techniques, from quantum chemical calculations providing more insight into possible reaction pathways and from transient experimentation dealing with reactions and reactors. This information is seldom combined into a kinetic model and into a quantitative description of the process. Generally the catalytic aspects are dealt with by chemists and by physicists, while the chemical engineers are called upon for mechanical aspects of the reactor design and its control. The symposium "Dynamics of Surfaces and Reaction Kinetics in Heterogeneous Catalysis" aims at illustrating a more global and concerted approach through a number of prestigious keynote lectures and severely screened oral and poster presentations.

Author: K Eguchi
Publisher: Elsevier
ISBN: 9780444532022
Category : Science
Languages : en
Pages : 682

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Unsteady-state operations of catalytic reactors provide plentiful opportunities for research and commercial realization of efficient heterogeneous catalytic processes. Forced unsteady state conditions generate unique distributions of process parameters and catalyst states often unattainable with traditional, steady-state operation. The unsteady-states can be created by periodic changes in input flow parameters, such as changes in inlet temperature and composition, catalyst circulation through reaction and regeneration zones, or periodic flow reversals through fixed catalyst bed. This can result in increased productivity, selectivity, capital savings and operating cost reduction (higher energy efficiency). Efficient environmental technologies for treatment of toxic emissions, acid rain and greenhouse gas emissions can also be developed using the unsteady-state concept. The Proceedings communicate recent progress in these areas of research and promote future development. The aims are to establish relations between academia, industry, engineers and scientists from all over the world, to stimulate new catalytic technologies as well as fundamental research, and to create new concepts for the development of effective catalytic systems. It presents the most up-to-date research in catalysis. - contains the most recent developments in catalytic research - includes research finding as well as their application to industry - a thorough source of information on the latest developments of industrial catalysis in Japan