Surface Studies of Metal Oxide Catalysts and Ultrathin Films PDF Download

Author: David Charles Grinter
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Author: D. C. Grinter
Publisher:
ISBN:
Category :
Languages : en
Pages :

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This thesis examines two important metal oxide systems: ultrathin CeO2(111) films on Pt(111), and carboxylic acids on TiO2 surfaces, both of which are significant for future energy research. The structure and growth of ultrathin films of CeO2(111) supported on Pt(111) have been studied with Scanning Tunnelling Microscopy (STM), Low Energy Electron Diffraction (LEED) and Auger Electron Spectroscopy (AES). The ultrathin films were grown in a number of ways and their growth mechanism, electronic structure, and domain boundaries were investigated using STM and STS. Atomically resolved STM images (filled and empty states) have been obtained on these ultrathin films permitting the identification of many defect structures. The behaviour of individual gold atoms at room temperature on ultrathin CeO2(111) films on Pt(111) has been investigated with STM. Simultaneous atomically resolved images of a gold adatom and the filled states of the ceria permitted the identification of two adsorption sites: (i) atop an oxygen atom and (ii) in a three-fold hollow site. The adsorption and reactivity of acetic acid on anatase TiO2(101) has also been investigated. It was found that at low coverage, acetic acid is observed to have a characteristic appearance consistent with a dissociative bidentate binding geometry to two neighbouring Ti5c sites. Deposition at elevated temperatures at saturation coverage yielded a (2 x 1) superstructure. The effects of heating, UV exposure, and tip pulsing were also investigated. STM has been used to investigate the adsorption and photo-reactivity of benzoic acid on rutile TiO2(110)(1 x 1) and (1 x 2). Benzoic acid binds to both surfaces dissociatively via a bridging geometry leading to a (2 x 1) overlayer on the (1 x 1) surface at saturation. Benzoate adsorbs between the added-rows of the (1 x 2) reconstruction leading to a (2 x 2) superstructure at higher coverage and demonstrated the important role of intermolecular interactions such as hydrogen bonding.

Author: Gianfranco Pacchioni
Publisher: John Wiley & Sons
ISBN: 3527640193
Category : Technology & Engineering
Languages : en
Pages : 368

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A wealth of information in one accessible book. Written by international experts from multidisciplinary fields, this in-depth exploration of oxide ultrathin films covers all aspects of these systems, starting with preparation and characterization, and going on to geometrical and electronic structure, as well as applications in current and future systems and devices. From the Contents: Synthesis and Preparation of Oxide Ultrathin Films Characterization Tools of Oxide Ultrathin Films Ordered Oxide Nanostructures on Metal Surfaces Unusual Properties of Oxides and Other Insulators in the Ultrathin Limit Silica and High-K Dielectrics Thin Films in Microelectronics Oxide Passive Films and Corrosion Protection Oxide Films as Catalytic Materials and as Models of Real Catalysts Oxide Films in Spintronics Oxide Ultrathin Films in Solid Oxide Fuel Cells Transparent Conducting and Chromogenic Oxide Films as Solar Energy Materials Oxide Ultrathin Films in Sensor Applications Ferroelectricity in Ultrathin Film Capacitors Titania Thin Films in Biocompatible Materials and Medical Implants Oxide Nanowires for New Chemical Sensor Devices

Author: J. Matharu
Publisher:
ISBN:
Category :
Languages : en
Pages :

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The properties of metal oxide surfaces are key to their diverse technological applications. However, the semiconducting nature of metal oxides presents a problem - many surface science techniques are electron based and thus require samples to be conducting. As such, bulk crystal studies of metal oxides by techniques such as photoemission spectroscopy (PES) and scanning tunneling microscopy (STM) are limited to reduced surfaces. Alternatively, thin films of a metal oxide can be synthesised on a suitable conducting substrate that mimic the bulk crystal surface whilst having sufficient conducting character to use these techniques. CeO2 is an important material found in three-way catalysts that remove pollutants from the exhaust gas of modern automobiles. Key to this application is the ability of reduced ceria to store and release oxygen depending on the composition of the exhaust. The addition of noble metals such as Pd to the ceria surface greatly improves the efficiency of pollutant conversion evidenced by X-ray photoelectron spectroscopy (XPS) by reducing the ceria. Resonance photoemission spectroscopy (RESPES) has been used to investigate the eect of Pd on ceria CeO2-x(110) thin films grown on a Pt(111) substrate. RESPES is more surface specific than XPS and thus reveals more information on the surface layers of ceria films. TiO2(110) is the most studied metal oxide surface, and has a multitude of applications. Its chemistry with two of the most abundant chemical species - water (H2O) and oxygen (O2) - is thus very important. H2O has been shown to dissociate on TiO2 surfaces. TiO2 thin films grown on W(100) were used as model system to study the chemistry of the reaction between TiO2 and H2O, and subsequently the reaction of hydrated surfaces with O2 using XPS. STM was used to examine the morphology of TiO2(110) films grown on W(100)-(2 x 1)-O, changes with film thickness and methods of improving surface smoothness. The first detailed STM images showing row structure of TiO2(110) films grown on W are shown.

Author: H.H. Kung
Publisher: Elsevier
ISBN: 0080887422
Category : Science
Languages : en
Pages : 299

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In this book the author presents an up-to-date summary of existing information on the structure, electronic properties, chemistry and catalytic properties of transition metal oxides. The subjects covered in the book can be divided into three sections. The first (chapters 1 to 3) covers the structural, physical, magnetic, and electronic properties of transition metal oxides. Although the emphasis is on surface properties, relevant bulk properties are also discussed. The second section (chapters 4 to 7) covers surface chemical properties. It includes topics that describe the importance of surface coordinative unsaturation in adsorption, the formation of surface acidity and the role of acidity in determining surface chemical properties, the nature and reactivities of adsorbed oxygen, and the surface chemistry in the reduction of oxides. The third section (chapters 8 to 14) is on the catalytic properties. Various catalytic reactions including decomposition, hydrogenation, isomerization, metathesis, selective oxidation, and reactions involving carbon oxides are discussed. Emphasis is placed more on reaction mechanisms and the role of catalysts than on kinetics and processes. Chapters on the preparation of oxide catalysts and on photo-assisted processes are also included. Whenever appropriate, relationships between various topics are indicated. Written for surface physicists, chemists, and catalytic engineers, the book will serve as a useful source of information for investigators and as a comprehensive overview of the subject for graduate students.

Author: Victor E. Henrich
Publisher: Cambridge University Press
ISBN: 9780521566872
Category : Science
Languages : en
Pages : 484

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Author: Adriana Zaleska-Medynska
Publisher: Elsevier
ISBN: 0128116331
Category : Technology & Engineering
Languages : en
Pages : 372

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Metal Oxide-Based Photocatalysis: Fundamentals and Prospects for Application explains the principles and fundamentals of metal oxide-based photocatalysis and the requirements necessary for their use in photocatalysis. It also discusses preparation methods for photocatalysis, and the advantages, disadvantages and achievements of the most important metal oxides (TiO2, ZnO, Fe2O3, Ta2O3, CuO, NiO, Cr2O3, RuO2, etc.). The book concludes with the most important photocatalytic applications and an overview of the future. Applications are organized by potential needs and solutions, addressing such areas as water treatment, hydrogen production, air treatment, chemical synthesis, and applications in medicine and construction. Provides coverage of applications, presenting needs and solutions Covers essential applications, such as water treatment, hydrogen production, air depollution, medical applications, and much more Includes the characterization of the most important metal oxides used in heterogeneous photocatalysis

Author: Falko P. Netzer
Publisher: Springer
ISBN: 3319283324
Category : Technology & Engineering
Languages : en
Pages : 403

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This book summarizes the current knowledge of two-dimensional oxide materials. The fundamental properties of 2-D oxide systems are explored in terms of atomic structure, electronic behavior and surface chemistry. The concept of polarity in determining the stability of 2-D oxide layers is examined, charge transfer effects in ultrathin oxide films are reviewed as well as the role of defects in 2-D oxide films. The novel structure concepts that apply in oxide systems of low dimensionality are addressed, and a chapter giving an overview of state-of-the-art theoretical methods for electronic structure determination of nanostructured oxides is included. Special emphasis is given to a balanced view from the experimental and the theoretical side. Two-dimensional materials, and 2-D oxides in particular, have outstanding behavior due to dimensionality and proximity effects. Several chapters treat prototypical model systems as illustrative examples to discuss the peculiar physical and chemical properties of 2-D oxide systems. The chapters are written by renowned experts in the field.

Author: Mario Rocca
Publisher: Springer Nature
ISBN: 3030469069
Category : Science
Languages : en
Pages : 1273

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Book Description
This handbook delivers an up-to-date, comprehensive and authoritative coverage of the broad field of surface science, encompassing a range of important materials such metals, semiconductors, insulators, ultrathin films and supported nanoobjects. Over 100 experts from all branches of experiment and theory review in 39 chapters all major aspects of solid-state surfaces, from basic principles to applications, including the latest, ground-breaking research results. Beginning with the fundamental background of kinetics and thermodynamics at surfaces, the handbook leads the reader through the basics of crystallographic structures and electronic properties, to the advanced topics at the forefront of current research. These include but are not limited to novel applications in nanoelectronics, nanomechanical devices, plasmonics, carbon films, catalysis, and biology. The handbook is an ideal reference guide and instructional aid for a wide range of physicists, chemists, materials scientists and engineers active throughout academic and industrial research.

Author: Falko P. Netzer
Publisher: Oxford University Press
ISBN: 0192571605
Category : Science
Languages : en
Pages : 346

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Book Description
Nanostructured oxide materials - ultra-thin films, nanoparticles and other nanometer-scale objects - play prominent roles in many aspects of our every-day life, in nature and in technological applications, among which is the all-oxide electronics of tomorrow. Due to their reduced dimensions and dimensionality, they strongly interact with their environment: gaseous atmosphere, water or support. Their novel physical and chemical properties are the subject of this book, from both a fundamental and an applied perspective. Oxide Thin Films and Nanostructures reviews and illustrates the various methodologies for their growth, fabrication, experimental and theoretical characterization. The role of key parameters such as film thickness, nanoparticle size and support interactions in driving their fundamental properties is underlined. At the ultimate thickness limit, two-dimensional oxide materials are generated, whose functionalities and potential applications are described. The emerging field of cation mixing is mentioned, which opens new avenues for engineering many oxide properties, as witnessed by natural oxide nanomaterials such as clay minerals, which, beyond their role at the Earth's surface, are now widely used in a whole range of human activities. Oxide nanomaterials are involved in many interdisciplinary fields of advanced nanotechnologies. Catalysis, photocatalysis, solar energy materials, fuel cells, corrosion protection, and biotechnological applications are amongst the areas where they are making an impact. The book outlines prototypical examples. A cautious glimpse into future developments of scientific activity is finally ventured to round off the presentation.