Download or read book Forcefield based Simulations of Bulk Structure of Mo V Te Nb O M1 Phase Catalysts for Selective Propane Ammoxidation to Acrylonitrile written by Yaroslav A. Kapustin and published by . This book was released on 2011 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of M1 Phase Molybdenum Based Mixed Metal Oxide Catalysts for Selective Oxidation of Propane written by Xin Li and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Acrylic acid and acrylonitrile are important intermediates for producing a number of common chemicals and materials used in paints, adhesives, plastics, fibers, etc. Traditionally, their production has relied on propylene feedstocks, and replacing propylene with the cheaper and more abundant propane as the raw material has attracted a lot of research interest during the past two decades. Several promising catalysts have been discovered, and to date, Mo-V-Nb-Te-O mixed metal oxides are the most efficient for both propane oxidation to acrylic acid and ammoxidation to acrylonitrile. Two orthorhombic phases named M1 and M2 have been identified as the major components, and M1 is generally considered the key factor for propane activation. In particular, the [001] face of the M1 structure has been proposed to provide active centers and the valence distribution on [001] face is believed to play an important role in determining the reaction mechanism. However, the detailed mechanism is not fully understood. This has limited opportunities to further improve catalysts performance or design better catalysts by rational means. This absence can be related to the past failure of generating M1 phase alone in synthesis, and many catalysts studied previously were actually mixtures. Thus, in this work, we carried out investigations of the highly pure M1 catalyst focusing on the synthesis, catalytic behavior, and structural model development. The hydrothermal method has been shown to yield M1 phase with high purity at the expense of a more complicated procedure. The simple slurry method was used by us to synthesize catalyst samples. It is found that, besides M1 and M2, tellurium molybdate TeMo 5 O 16, V-substituted Mo 5 O 14 or (V, Mo) 5 O 14, and Mosubstituted V 2 O 5 or (Mo, V) 2 O 5 are also often formed together. The final phase composition can be significantly affected by nominal metal composition, slurry pH, calcination heating rate, etc. And the relative amount of each phase under different conditions can be directly correlated with respective V/Mo and Te/Mo ratios. Further, an additional purification step where the sample mixture is washed by H 2 O 2 solution was studied, and it is observed that concentrated hydrogen peroxide offers the most effective removal of undesired phases. A complete procedure for obtaining M1 phase in high purity has been developed. Synthesized M1 catalysts were characterized by EDS and XPS, and results suggest that the M1 structure shows high chemical flexibility and can contain vanadium to quite different levels depending on the nominal metal stoichiometry in the slurry. In particular, it is seen that the more vanadium in the slurry, the more vanadium in the final M1 structure. Additionally, no significant difference between the surface and the bulk was observed with respect to metal composition.
Download or read book Surface Termination of M1 Phase and Rational Design of Propane Ammoxidation Catalysts written by and published by . This book was released on 2015 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report describes major accomplishments in this research project which has demonstrated that the M1 phase is the only crystalline phase required for propane ammoxidation to acrylonitrile and that a surface monolayer terminating the ab planes of the M1 phase is responsible for their activity and selectivity in this reaction. Fundamental studies of the topmost surface chemistry and mechanism of propane ammoxidation over the Mo-V-(Te,Sb)-(Nb,Ta)-O M1 and M2 phases resulted in the development of quantitative understanding of the surface molecular structure – reactivity relationships for this unique catalytic system. These oxides possess unique catalytic properties among mixed metal oxides, because they selectively catalyze three alkane transformation reactions, namely propane ammoxidation to acrylonitrile, propane oxidation to acrylic acid and ethane oxidative dehydrogenation, all of considerable economic significance. Therefore, the larger goal of this research was to expand this catalysis to other alkanes of commercial interest, and more broadly, demonstrate successful approaches to rational design of improved catalysts that can be applied to other selective (amm)oxidation processes.
Download or read book M1 to M2 Phase Transformation in Mo V Te O Catalysts for Selective Amm Oxidation of Propane written by Vadim Guliants and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid State Chemistry in Catalysis written by Robert K. Grasselli and published by . This book was released on 1985 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Good,No Highlights,No Markup,all pages are intact, Slight Shelfwear,may have the corners slightly dented, may have slight color changes/slightly damaged spine.
Download or read book Supported Mo V Nb W O Catalysts for the Selective Oxidation of Propane written by Giacomo Grasso and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Materials Chemistry and Biochemistry From Bold Initiatives to the Last Mile written by Sadasivan Shankar and published by Springer Nature. This book was released on 2021-01-25 with total page 1344 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a broad and nuanced overview of the achievements and legacy of Professor William (“Bill”) Goddard in the field of computational materials and molecular science. Leading researchers from around the globe discuss Goddard’s work and its lasting impacts, which can be seen in today’s cutting-edge chemistry, materials science, and biology techniques. Each section of the book closes with an outline of the prospects for future developments. In the course of a career spanning more than 50 years, Goddard’s seminal work has led to dramatic advances in a diverse range of science and engineering fields. Presenting scientific essays and reflections by students, postdoctoral associates, collaborators and colleagues, the book describes the contributions of one of the world’s greatest materials and molecular scientists in the context of theory, experimentation, and applications, and examines his legacy in each area, from conceptualization (the first mile) to developments and extensions aimed at applications, and lastly to de novo design (the last mile). Goddard’s passion for science, his insights, and his ability to actively engage with his collaborators in bold initiatives is a model for us all. As he enters his second half-century of scientific research and education, this book inspires future generations of students and researchers to employ and extend these powerful techniques and insights to tackle today’s critical problems in biology, chemistry, and materials. Examples highlighted in the book include new materials for photocatalysts to convert water and CO2 into fuels, novel catalysts for the highly selective and active catalysis of alkanes to valuable organics, simulating the chemistry in film growth to develop two-dimensional functional films, and predicting ligand–protein binding and activation to enable the design of targeted drugs with minimal side effects.
Download or read book Spectra and Energy Levels of Rare Earth Ions in Crystals written by Gerhard Heinrich Dieke and published by . This book was released on 1968 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanostructured Catalysts written by Christian Hess and published by Royal Society of Chemistry. This book was released on 2011-07-22 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive up-to-date summary of the existing information on the structural/electronic properties, chemistry and catalytic properties of vanadium and molybdenum containing catalysts. It discusses the importance of nanoscience for the controlled synthesis of catalysts with functional properties and introduces the necessary background regarding surface properties and preparation techniques, leading from a textbook level to the current state of knowledge. Then follows an extensive survey and analysis of the existing open and patent literature - an essential knowledge source for the development of the new generation of partial oxidation catalysts. Important examples from current research on partial oxidation reactions are reviewed from experts in the field. The next chapter discusses the importance of 2- and 3-dimensional model systems for a fundamental understanding of the structure of transition metal oxide catalysts and its correlation to reactivity. Finally, an outlook on research opportunities within the area of partial oxidation reactions is presented.
Download or read book Fundamentals of Natural Fibres and Textiles written by Md. Ibrahim H. Mondal and published by Woodhead Publishing. This book was released on 2021-03-20 with total page 817 pages. Available in PDF, EPUB and Kindle. Book excerpt: The textile industry is focused in its search for alternative green fibres with the aim of providing high-quality products which are fully recyclable and biodegradable. Natural textile materials from renewable sources play an increasingly important role in the industry due to their unique properties and functionality over synthetic fibres, as well as their sustainability. Fundamentals of Natural Fibres and Textiles covers all the fundamental and basic information about natural fibres and textiles. Many different fibres are covered from their origin, through processing, properties, and applications. The latest methods for characterisation and testing of natural fibres are all addressed with reference to cutting-edge industry trends. This uniquely comprehensive approach to the topic provides the ideal entry point to natural fibres for textile and clothing scientists, engineers, designers, researchers, students, and manufacturers of such products. - Explains the characteristics of natural fibres to show how they compare to synthetic fibres for a range of purposes - Provides an overview of the environmental impact of the processing of fibres and how this creates industrial waste - Covers a wide range of natural fibres in detail, from traditional silk and wool to electrospun biopolymers - Provides the latest updates on technologies for designing natural fibres and applying them to the development of new products
Download or read book The Chemistry of Membranes Used in Fuel Cells written by Shulamith Schlick and published by John Wiley & Sons. This book was released on 2018-02-13 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examines the important topic of fuel cell science by way of combining membrane design, chemical degradation mechanisms, and stabilization strategies This book describes the mechanism of membrane degradation and stabilization, as well as the search for stable membranes that can be used in alkaline fuel cells. Arranged in ten chapters, the book presents detailed studies that can help readers understand the attack and degradation mechanisms of polymer membranes and mitigation strategies. Coverage starts from fundamentals and moves to different fuel cell membrane types and methods to profile and analyze them. The Chemistry of Membranes Used in Fuel Cells: Degradation and Stabilization features chapters on: Fuel Cell Fundamentals: The Evolution of Fuel Cells and their Components; Degradation Mechanism of Perfluorinated Membranes; Ranking the Stability of Perfluorinated Membranes Used in Fuel Cells to Attack by Hydroxyl Radicals; Stabilization Mechanism of Perfluorinated Membranes by Ce(III) and Mn(II); Hydrocarbon Proton Exchange Membranes; Stabilization of Perfluorinated Membranes Using Nanoparticle Additives; Degradation Mechanism in Aquivion Perfluorinated Membranes and Stabilization Strategies; Anion Exchange Membrane Fuel Cells: Synthesis and Stability; In-depth Profiling of Degradation Processes in Nafion Due to Pt Dissolution and Migration into the Membrane; and Quantum Mechanical Calculations of the Degradation Mechanism in Perfluorinated Membranes. Brings together aspects of membrane design, chemical degradation mechanisms and stabilization strategies Emphasizes chemistry of fuel cells, which is underemphasized in other books Includes discussion of fuel cell performance and behavior, analytical profiling methods, and quantum mechanical calculations The Chemistry of Membranes Used in Fuel Cells is an ideal book for polymer scientists, chemists, chemical engineers, electrochemists, material scientists, energy and electrical engineers, and physicists. It is also important for grad students studying advanced polymers and applications.
Download or read book Selective Hydrocarbon Activation written by Julian A. Davies and published by Wiley-VCH. This book was released on 1990 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the principles, current research and ideas related to taking naturally occurring petroleum by-products and making them into useful products. This book aims to introduce nonspecialists to the field and provide them with current knowledge contributed by experts in inorganic, organic, catalysis chemistries and biochemistry. The focus is on homogeneous metal-based chemistry with an emphasis on mechanism and energetics. Selective Hydrocarbon Activation is a blend of theory and experiment and is of interest to both academics and those in industry.
Download or read book Nanoalloys written by Dominique Bazin and published by Elsevier Inc. Chapters. This book was released on 2013-03-12 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:
