Modélisation de la structure et de la réactivité de la pérovskite LaFeO3 dopée

Modélisation de la structure et de la réactivité de la pérovskite LaFeO3 dopée PDF Author: Dimitri Blanck
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

Get Book Here

Book Description
La dépollution des gaz d'échappement des véhicules essence est opérée par catalyse trois voies (CTV). Ce terme désigne la combinaison de trois réactions : l'oxydation du CO en CO2, la combustion des hydrocarbures imbrûlés et la réduction des NOx. Les catalyseurs 3-voies actuels sont constitués de nanoparticules de métaux nobles (Pt, Rh, Pd...) dispersés sur un support oxyde. En raison de leur prix élevés de nombreuse recherche vise à limiter leur utilisation. Utilisées depuis le milieu des années 70 en catalyse en tant que support, les pérovskites sont une alternative possible. Dans le cas de la catalyse trois voies, les capacités oxydo-réductrices intrinsèques du fer font de la pérovskite LaFeO3 (LFO) un candidat intéressant pour la réduction des NOx et l'oxydation du CO. A ce jour, les mécanismes réactionnels de même que les sites actifs de ce catalyseur sont inconnus. Il est donc important de les mettre en évidence pour permettre une amélioration rationnelle des activités et sélectivités des catalyseurs 3 voies de nouvelle génération. Dans cette étude nous avons cherché à déterminer le mécanisme réactionnel sur la pérovskite. Dans un premier nous avons cherché à étudier l'état de surface de la pérovskite en présence d'eau et déterminer les surfaces présentes. Puis nous avons calculé la thermochimie d'un ensemble de réaction élémentaire sur les surfaces pour enfin proposé un mécanisme réactionnel possible de réduction de NO et d'oxydation de CO. Après détermination des états de transition nous avons cherché à optimiser la formulation de la pérovskite en dopant les surfaces en métaux de transition.

Modélisation de la structure et de la réactivité de la pérovskite LaFeO3 dopée

Modélisation de la structure et de la réactivité de la pérovskite LaFeO3 dopée PDF Author: Dimitri Blanck
Publisher:
ISBN:
Category :
Languages : fr
Pages : 0

Get Book Here

Book Description
La dépollution des gaz d'échappement des véhicules essence est opérée par catalyse trois voies (CTV). Ce terme désigne la combinaison de trois réactions : l'oxydation du CO en CO2, la combustion des hydrocarbures imbrûlés et la réduction des NOx. Les catalyseurs 3-voies actuels sont constitués de nanoparticules de métaux nobles (Pt, Rh, Pd...) dispersés sur un support oxyde. En raison de leur prix élevés de nombreuse recherche vise à limiter leur utilisation. Utilisées depuis le milieu des années 70 en catalyse en tant que support, les pérovskites sont une alternative possible. Dans le cas de la catalyse trois voies, les capacités oxydo-réductrices intrinsèques du fer font de la pérovskite LaFeO3 (LFO) un candidat intéressant pour la réduction des NOx et l'oxydation du CO. A ce jour, les mécanismes réactionnels de même que les sites actifs de ce catalyseur sont inconnus. Il est donc important de les mettre en évidence pour permettre une amélioration rationnelle des activités et sélectivités des catalyseurs 3 voies de nouvelle génération. Dans cette étude nous avons cherché à déterminer le mécanisme réactionnel sur la pérovskite. Dans un premier nous avons cherché à étudier l'état de surface de la pérovskite en présence d'eau et déterminer les surfaces présentes. Puis nous avons calculé la thermochimie d'un ensemble de réaction élémentaire sur les surfaces pour enfin proposé un mécanisme réactionnel possible de réduction de NO et d'oxydation de CO. Après détermination des états de transition nous avons cherché à optimiser la formulation de la pérovskite en dopant les surfaces en métaux de transition.

Perovskite Oxide for Solid Oxide Fuel Cells

Perovskite Oxide for Solid Oxide Fuel Cells PDF Author: Tatsumi Ishihara
Publisher: Springer Science & Business Media
ISBN: 0387777083
Category : Technology & Engineering
Languages : en
Pages : 310

Get Book Here

Book Description
Fuel cell technology is quite promising for conversion of chemical energy of hydrocarbon fuels into electricity without forming air pollutants. There are several types of fuel cells: polymer electrolyte fuel cell (PEFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), solid oxide fuel cell (SOFC), and alkaline fuel cell (AFC). Among these, SOFCs are the most efficient and have various advantages such as flexibility in fuel, high reliability, simple balance of plant (BOP), and a long history. Therefore, SOFC technology is attracting much attention as a power plant and is now close to marketing as a combined heat and power generation system. From the beginning of SOFC development, many perovskite oxides have been used for SOFC components; for example, LaMnO -based oxide for the cathode and 3 LaCrO for the interconnect are the most well known materials for SOFCs. The 3 current SOFCs operate at temperatures higher than 1073 K. However, lowering the operating temperature of SOFCs is an important goal for further SOFC development. Reliability, durability, and stability of the SOFCs could be greatly improved by decreasing their operating temperature. In addition, a lower operating temperature is also beneficial for shortening the startup time and decreasing energy loss from heat radiation. For this purpose, faster oxide ion conductors are required to replace the conventional Y O -stabilized ZrO 2 3 2 electrolyte. A new class of electrolytes such as LaGaO is considered to be 3 highly useful for intermediate-temperature SOFCs.

Oxide Electronics

Oxide Electronics PDF Author: Asim K. Ray
Publisher: John Wiley & Sons
ISBN: 1119529476
Category : Technology & Engineering
Languages : en
Pages : 628

Get Book Here

Book Description
Oxide Electronics Multiple disciplines converge in this insightful exploration of complex metal oxides and their functions and properties Oxide Electronics delivers a broad and comprehensive exploration of complex metal oxides designed to meet the multidisciplinary needs of electrical and electronic engineers, physicists, and material scientists. The distinguished author eschews complex mathematics whenever possible and focuses on the physical and functional properties of metal oxides in each chapter. Each of the sixteen chapters featured within the book begins with an abstract and an introduction to the topic, clear explanations are presented with graphical illustrations and relevant equations throughout the book. Numerous supporting references are included, and each chapter is self-contained, making them perfect for use both as a reference and as study material. Readers will learn how and why the field of oxide electronics is a key area of research and exploitation in materials science, electrical engineering, and semiconductor physics. The book encompasses every application area where the functional and electronic properties of various genres of oxides are exploited. Readers will also learn from topics like: Thorough discussions of High-k gate oxide for silicon heterostructure MOSFET devices and semiconductor-dielectric interfaces An exploration of printable high-mobility transparent amorphous oxide semiconductors Treatments of graphene oxide electronics, magnetic oxides, ferroelectric oxides, and materials for spin electronics Examinations of the calcium aluminate binary compound, perovoksites for photovoltaics, and oxide 2Degs Analyses of various applications for oxide electronics, including data storage, microprocessors, biomedical devices, LCDs, photovoltaic cells, TFTs, and sensors Suitable for researchers in semiconductor technology or working in materials science, electrical engineering, and physics, Oxide Electronics will also earn a place in the libraries of private industry researchers like device engineers working on electronic applications of oxide electronics. Engineers working on photovoltaics, sensors, or consumer electronics will also benefit from this book.

Nanoscale Materials

Nanoscale Materials PDF Author: Luis M. Liz-Marzán
Publisher: Springer Science & Business Media
ISBN: 0306481081
Category : Science
Languages : en
Pages : 506

Get Book Here

Book Description
Organized nanoassemblies of inorganic nanoparticles and organic molecules are building blocks of nanodevices, whether they are designed to perform molecular level computing, sense the environment or improve the catalytic properties of a material. The key to creation of these hybrid nanostructures lies in understanding the chemistry at a fundamental level. This book serves as a reference book for researchers by providing fundamental understanding of many nanoscopic materials.

Organic-Inorganic Halide Perovskite Photovoltaics

Organic-Inorganic Halide Perovskite Photovoltaics PDF Author: Nam-Gyu Park
Publisher: Springer
ISBN: 3319351141
Category : Technology & Engineering
Languages : en
Pages : 366

Get Book Here

Book Description
This book covers fundamentals of organometal perovskite materials and their photovoltaics, including materials preparation and device fabrications. Special emphasis is given to halide perovskites. The opto-electronic properties of perovskite materials and recent progress in perovskite solar cells are described. In addition, comments on the issues to current and future challenges are mentioned.

Spin Electronics

Spin Electronics PDF Author: Michael Ziese
Publisher: Springer
ISBN: 3540452583
Category : Technology & Engineering
Languages : en
Pages : 448

Get Book Here

Book Description
For 50 years conventional electronics has ignored the electron spin. The manipulation and utilisation of the electron spin heralds an exciting and rapidly changing era in electronics, combining the disciplines of magnetism and traditional electronics. The first generation of "spintronic" devices (such as read heads based on giant magnetoresistance or non-volatile magnetic random access memories) have already gained dominant positions in the market place. This volume, the first of its kind on spin electronics describes all the essential topics for new researchers entering the field. It covers magnetism and semiconductor basics, micromagnetism, experimental techniques, materials science, device fabrication and new developments in spin-dependent processes. At the end of most chapters are a number of exercises and worked problems to aid the reader in understanding this fascinating new field.

Multifunctional Oxide Heterostructures

Multifunctional Oxide Heterostructures PDF Author: Evgeny Y. Tsymbal
Publisher: OUP Oxford
ISBN: 0191642223
Category : Science
Languages : en
Pages : 416

Get Book Here

Book Description
This book is devoted to the rapidly developing field of oxide thin-films and heterostructures. Oxide materials combined with atomic-scale precision in a heterostructure exhibit an abundance of macroscopic physical properties involving the strong coupling between the electronic, spin, and structural degrees of freedom, and the interplay between magnetism, ferroelectricity, and conductivity. Recent advances in thin-film deposition and characterization techniques made possible the experimental realization of such oxide heterostructures, promising novel functionalities and device concepts. The book consists of chapters on some of the key innovations in the field over recent years, including strongly correlated oxide heterostructures, magnetoelectric coupling and multiferroic materials, thermoelectric phenomena, and two-dimensional electron gases at oxide interfaces. The book covers the core principles, describes experimental approaches to fabricate and characterize oxide heterostructures, demonstrates new functional properties of these materials, and provides an overview of novel applications.

Handbook of Gas Sensor Materials

Handbook of Gas Sensor Materials PDF Author: Ghenadii Korotcenkov
Publisher: Springer Science & Business Media
ISBN: 1461471656
Category : Science
Languages : en
Pages : 454

Get Book Here

Book Description
The two volumes of Handbook of Gas Sensor Materials provide a detailed and comprehensive account of materials for gas sensors, including the properties and relative advantages of various materials. Since these sensors can be applied for the automation of myriad industrial processes, as well as for everyday monitoring of such activities as public safety, engine performance, medical therapeutics, and in many other situations, this handbook is of great value. Gas sensor designers will find a treasure trove of material in these two books.

Advanced Ceramics for Energy Conversion and Storage

Advanced Ceramics for Energy Conversion and Storage PDF Author: Olivier Guillon
Publisher: Elsevier
ISBN: 0081027842
Category : Technology & Engineering
Languages : en
Pages : 750

Get Book Here

Book Description
In order to enable an affordable, sustainable, fossil-free future energy supply, research activities on relevant materials and related technologies have been intensified in recent years, Advanced Ceramics for Energy Conversion and Storage describes the current state-of-the-art concerning materials, properties, processes, and specific applications. Academic and industrial researchers, materials scientists, and engineers will be able to get a broad overview of the use of ceramics in energy applications, while at the same time become acquainted with the most recent developments in the field. With chapters written by recognized experts working in their respective fields the book is a valuable reference source covering the following application areas: ceramic materials and coatings for gas turbines; heat storage and exchange materials for solar thermal energy; ceramics for nuclear energy; ceramics for energy harvesting (thermoelectrics, piezoelectrics, and sunlight conversion); ceramic gas separation membranes; solid oxide fuel cells and electrolysers; and electrochemical storage in battery cells. Advanced Ceramics for Energy Conversion and Storage offers a sound base for understanding the complex requirements related to the technological fields and the ceramic materials that make them possible. The book is also suitable for people with a solid base in materials science and engineering that want to specialize in ceramics. - Presents an extensive overview of ceramic materials involved in energy conversion and storage - Updates on the tremendous progress that has been achieved in recent years - Showcases authors at the forefront of their fields, including results from the huge amount of published data - Provides a list of requirements for the materials used for each energy technology - Includes an evaluation and comparison of materials available, including their structure, properties and performance

Nonstoichiometric Oxides

Nonstoichiometric Oxides PDF Author: O.T. Soerensen
Publisher: Elsevier
ISBN: 0323149804
Category : Science
Languages : en
Pages : 454

Get Book Here

Book Description
Nonstoichiometric Oxides discusses the thermodynamic and structural studies of nonstoichiometric oxides. This eight-chapter text also covers the defect-defect interactions in these compounds. The introductory chapters describe the thermodynamic properties of nonstoichiometric oxides in terms of defect complexes using the classical thermodynamic principles and from a statistical thermodynamics point of view. These chapters also include statistical thermodynamic models that indicate the ordered nonstoichiometric phase range in these oxides. The subsequent chapters examine the transport properties, such as diffusion and electrical conductivity. Diffusion theories and experimental diffusion coefficients for several systems, as well as the electrical properties of the highly defective ionic and mixed oxide conductor, are specifically tackled in these chapters. The concluding chapters present the pertinent results obtained in nonstoichiometric oxide structural studies using high-resolution electron microscopy and X-ray and neutron diffraction. Inorganic chemists and inorganic chemistry teachers and students will greatly appreciate this book.