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M1 To M2 Phase Transformation In Mo V Te O Catalysts For Selective Amm Oxidation Of Propane
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Book Synopsis M1 to M2 Phase Transformation in Mo-V-Te-O Catalysts for Selective (Amm) Oxidation of Propane by : Vadim Guliants
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:
Book Synopsis Surface Termination of M1 Phase and Rational Design of Propane Ammoxidation Catalysts by :
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.
Book Synopsis Investigation of M1 Phase Molybdenum Based Mixed Metal Oxide Catalysts for Selective Oxidation of Propane by : Xin Li
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.
Book Synopsis Nanotechnology in Catalysis, 3 Volumes by : Bert F. Sels
Download or read book Nanotechnology in Catalysis, 3 Volumes written by Bert F. Sels and published by John Wiley & Sons. This book was released on 2017-10-16 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses Handbuch präsentiert die in den letzten zehn Jahren entstandenen neuen Anwendungsbereiche und gibt einen umfassenden Überblick über dieses wissenschaftlich und ökonomisch wichtige Gebiet. Einzigartig ist die Verbindung von Grundlagenforschung und industrieller Entwicklung.
Book Synopsis Metal Oxides in Heterogeneous Catalysis by : Jacques C. Vedrine
Download or read book Metal Oxides in Heterogeneous Catalysis written by Jacques C. Vedrine and published by Elsevier. This book was released on 2018-01-11 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxides in Heterogeneous Catalysis is an overview of the past, present and future of heterogeneous catalysis using metal oxides catalysts. The book presents the historical, theoretical, and practical aspects of metal oxide-based heterogeneous catalysis. Metal Oxides in Heterogeneous Catalysis deals with fundamental information on heterogeneous catalysis, including reaction mechanisms and kinetics approaches.There is also a focus on the classification of metal oxides used as catalysts, preparation methods and touches on zeolites, mesoporous materials and Metal-organic frameworks (MOFs) in catalysis. It will touch on acid or base-type reactions, selective (partial) and total oxidation reactions, and enzymatic type reactions The book also touches heavily on the biomass applications of metal oxide catalysts and environmentally related/depollution reactions such as COVs elimination, DeNOx, and DeSOx. Finally, the book also deals with future trends and prospects in metal oxide-based heterogeneous catalysis. Presents case studies in each chapter that provide a focus on the industrial applications Includes fundamentals, key theories and practical applications of metal oxide-based heterogeneous catalysis in one comprehensive resource Edited, and contributed, by leading experts who provide perspectives on synthesis, characterization and applications
Book Synopsis Springer Handbook of Advanced Catalyst Characterization by : Israel E. Wachs
Download or read book Springer Handbook of Advanced Catalyst Characterization written by Israel E. Wachs and published by Springer Nature. This book was released on 2023-06-12 with total page 1109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Co-edited by world-renowned scientists in the field of catalysis, this book contains the cutting-edge in situ and operando spectroscopy characterization techniques operating under reaction conditions to determine a materials’ bulk, surface, and solution complex and their applications in the field of catalysis with emphasis on solid catalysts in powder form since such catalyst are relevant for industrial applications. The handbook covers from widely-used to cutting-edge techniques. The handbook is written for a broad audience of students and professionals who want to pursue the full capabilities available by the current state-of-the-art in characterization to fully understand how their catalysts really operate and guide the rational design of advanced catalysts. Individuals involved in catalysis research will be interested in this handbook because it contains a catalogue of cutting-edge methods employed in characterization of catalysts. These techniques find wide use in applications such as petroleum refining, chemical manufacture, natural gas conversion, pollution control, transportation, power generation, pharmaceuticals and food processing. fdsfds
Book Synopsis Nanotechnology in Catalysis by : Bert Sels
Download or read book Nanotechnology in Catalysis written by Bert Sels and published by John Wiley & Sons. This book was released on 2017-06-21 with total page 1500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reflecting the R&D efforts in the field that have resulted in a plethora of novel applications over the past decade, this handbook gives a comprehensive overview of the tangible benefits of nanotechnology in catalysis. By bridging fundamental research and industrial development, it provides a unique perspective on this scientifically and economically important field. While the first three parts are devoted to preparation and characterization of nanocatalysts, the final three provide in-depth insights into their applications in the fine chemicals industry, the energy industry, and for environmental protection, with expert authors reporting on real-life applications that are on the brink of commercialization. Timely reading for catalytic chemists, materials scientists, chemists in industry, and process engineers.
Book Synopsis Nanocatalysis by : Vanesa Calvino-Casilda
Download or read book Nanocatalysis written by Vanesa Calvino-Casilda and published by CRC Press. This book was released on 2019-02-14 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis and design of new nanocatalysts is an important area of research that aims to introduce multiple types of useful applications in a greener market. The necessity of nanostructuring the active sites has emerged as the key point in a successful design of the catalysts. The book covers the progress in this research area done in the last ten years. It includes the classification of catalysts and structure of active sites at the nanoscale. The book covers examples to present the concept, evolution of nanocatalysts from the perspective of chemistry of materials and their applications.
Book Synopsis Metal Oxide Catalysis, 2 Volume Set by : S. David Jackson
Download or read book Metal Oxide Catalysis, 2 Volume Set written by S. David Jackson and published by John Wiley & Sons. This book was released on 2008-12-23 with total page 887 pages. Available in PDF, EPUB and Kindle. Book excerpt: With its two-volume structure, this handbook and ready reference allows for comprehensive coverage of both characterization and applications, while uniform editing throughout ensures that the structure remains consistent. The result is an up-to-date review of metal oxides in catalysis. The first volume covers a range of techniques that are used to characterize oxides, with each chapter written by an expert in the field. Volume 2 goes on to cover the use of metal oxides in catalytic reactions. For all chemists and engineers working in the field of heterogeneous catalysis.
Book Synopsis Mesoporous and Macroporous Mixed Metal Oxide MoVTeNbOx Catalysts for Propane (amm) Oxidation by :
Download or read book Mesoporous and Macroporous Mixed Metal Oxide MoVTeNbOx Catalysts for Propane (amm) Oxidation written by and published by . This book was released on 2008 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Approximately 5 million metric tons of acrylonitrile are produced worldwide annually for the manufacture of acrylic fibers, copolymers and reinforced carbon fibers. There is currently intense commercial interest in developing a new catalytic process for acrylonitrile production via propane ammoxidation employing multicomponent mixed metal oxides, which would replace the existing propylene ammoxidation technology. This new technology is expected to lower the production cost by 30% as compared to the existing process because of the lower cost of propane and increased production of valuable co-products, such as acetonitrile. The key to the success of this important technology is the development of novel mixed metal oxide catalysts that can selectively ammoxidize propane to acrylonitrile. Recent developments in macroscale and mesoscale structure-directed self-assembly offer many attractive possibilities for the molecular design of novel catalytic mixed metal oxides. The present work describes the development of novel synthesis approaches for macroporous and mesoporous mixed metal MoVTe(Sb)NbOx catalysts displaying ordered porous structures, high surface areas, flexible compositions and improved thermal stability for propane ammoxidation. This research began with systematic exploration of synthesis of mesoporous Nb2O5 oxides as a departure point in the subsequent synthesis of mixed M-Nb-O (M=Mo, V, Te, Sb) oxides employing Nb2O5 as the major component or the catalytic support. Nb2O5 was chosen for this study as the most stable metal oxide possessing the highest Tammann temperature among all constituent metal oxides (MoOx, VOx, TeOx and SbOx). Thermally stable (up to 500 °C) and well-defined two-dimensional hexagonal mesostructured niobium oxides were obtained possessing the surface areas of up to 210 m2/g. The pore size of mesoporous niobium oxides was for the first time tuned in a wide range from 4.6 to 21 nm by varying synthesis conditions. As compared with previous studies, mesoporous niobium oxides with tunable pore sizes obtained in this work possessed more attractive pores structures which make them promising as catalytic supports or a major component in the synthesis of improved MoVTeNbOx catalysts for selective (amm)oxidation of propane. Thermally stable mesoporous binary (Nb-M-O, M=Mo, V, or Sb), multicomponent (MNbOx, M=Mo+V+Te) and supported (M/Nb, M=Mo+V+Te+Nb) mixed metal oxide catalysts were for the first time synthesized by evaporation-induced self-assembly and incipient-wetness impregnation techniques. These mixed metal oxide phases displayed good thermal stability of amorphous inorganic wall (up to 400°C), large pore sizes (5-23 nm), high surface areas (up to 232 m2/g) and flexible inorganic wall compositions. Improved dispersion of active components in the Nb2O5 matrix and over the Nb2O5 support was observed. However, the desirable M1 phase was not observed in the products of thermal transformation of these mesoporous mixed metal oxides probably due to insufficient thickness of inorganic walls in these phases. In order to investigate nucleation of the catalytic M1 phase and further improve the thermal stability of the ordered porous structure, MoVTeNbOx phases displaying both macroporous and mesoporous structures were prepared by a dual templating approach employing colloidal arrays of polystyrene spheres and non-ionic surfactants. The MoVTeNbOx phases possessing such dual porosity were obtained after polystyrene spheres and non-ionic surfactants were removed in a low temperature calcination step. These hierarchical MoVTeNbOx phases displaying bimodal pore structure transformed into macroporous rutile phase possessing nanocrystalline inorganic walls at high temperature. These MoVTeNbOx rutile phases possessed high surface areas (70 m2/g), desirable pore architectures, robust nanocrystalline inorganic walls and enhanced thermal stability (up to 600 °C). Although these macroporous MoVTeNbOx rutile catalysts displayed lower activity in propane ammoxidation and lower acrylonitrile selectivity in propane ammoxidation as compared to the active and selective M1 phase, the novel synthesis method reported in these studies represents a promising general approach to design novel complex mixed metal oxides for a wide range of applications in selective oxidation catalysis.
Book Synopsis Basic Principles in Applied Catalysis by : Manfred Baerns
Download or read book Basic Principles in Applied Catalysis written by Manfred Baerns and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by a team of internationally recognized experts, this book addresses the most important types of catalytic reactions and catalysts as used in industrial practice. Both applied aspects and the essential scientific principles are described. The main topics can be summarized as follows: heterogeneous, homogeneous and biocatalysis, catalyst preparation and characterization, catalytic reaction engineering and kinetics, catalyst deactivation and industrial perspective.
Book Synopsis Modern Heterogeneous Oxidation Catalysis by : Noritaka Mizuno
Download or read book Modern Heterogeneous Oxidation Catalysis written by Noritaka Mizuno and published by John Wiley & Sons. This book was released on 2009-11-18 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filling a gap in the current literature, this comprehensive reference presents all important catalyst classes, including metal oxides, polyoxometalates, and zeolites. Readers will find here everything they need to know -- from structure design to characterization, and from immobilization to industrial processes. A true must-have for anyone working in this key technology.
Book Synopsis Characterization of Solid Materials and Heterogeneous Catalysts by : Michel Che
Download or read book Characterization of Solid Materials and Heterogeneous Catalysts written by Michel Che and published by John Wiley & Sons. This book was released on 2012-04-16 with total page 1313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume book provides an overview of physical techniques used to characterize the structure of solid materials, on the one hand, and to investigate the reactivity of their surface, on the other. Therefore this book is a must-have for anyone working in fields related to surface reactivity. Among the latter, and because of its most important industrial impact, catalysis has been used as the directing thread of the book. After the preface and a general introduction to physical techniques by M. Che and J.C. Vedrine, two overviews on physical techniques are presented by G. Ertl and Sir J.M. Thomas for investigating model catalysts and porous catalysts, respectively. The book is organized into four parts: Molecular/Local Spectroscopies, Macroscopic Techniques, Characterization of the Fluid Phase (Gas and/ or Liquid), and Advanced Characterization. Each chapter focuses upon the following important themes: overview of the technique, most important parameters to interpret the experimental data, practical details, applications of the technique, particularly during chemical processes, with its advantages and disadvantages, conclusions.
Book Synopsis The Mechanism of Propane Ammoxidation Over the Ab Plane of the Mo-V-Te-Nb-O M1 Phase Probed by Density Functional Theory by : Junjun Yu
Download or read book The Mechanism of Propane Ammoxidation Over the Ab Plane of the Mo-V-Te-Nb-O M1 Phase Probed by Density Functional Theory written by Junjun Yu and published by . This book was released on 2015 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: The selective ammoxidation of propane into acrylonitrile catalyzed by the bulk Mo-V-Te-Nb-O system received considerable attention because it is more environmentally benign than the current process of propylene ammoxidation and relies on a more abundant feedstock. This process consists of a series of elementary steps including propane oxidative dehydrogenation (ODH), ammonia and O2 activation, and N-insertion into C3 surface intermediates. However, the limited fundamental understanding of the reaction mechanism and the roles of the different cations have hindered the progress in further improving the activity and selectivity of these catalysts required for the commercial application. In this thesis, we present and discuss the results of the density functional theory (DFT) calculations performed to investigate the overall propane ammoxidation pathway employing the cluster models of the proposed selective and active sites present in the surface ab plane of the so-called M1 phase, which is the main catalytic phase present in the bulk mixed Mo-V-Te-Nb oxides. The activation energies for the oxidative dehydrogenation (ODH) of propane and sequentially formed intermediates (isopropyl, propene, and allyl) were calculated for different surface cation sites. Propane activation on V5=O was found to be the rate-limiting step (Ea = 1.2 eV), consistent with the current proposed reaction mechanism for propane activation on the bulk mixed Mo-V-Te-Nb oxides and the current understanding of V5+ as the active site for alkane activation present in V-based mixed oxides. Furthermore, a linear relationship was established between the H adsorption energy and the activation energy for H abstraction from various C3 intermediates, which is highly useful for predicting the energy barriers of H abstraction from C3 species based solely on H adsorption energy. The energy barriers of ammonia activation on different surface sites and NH insertion into the allyl species were investigated and discussed in terms of the hypothetical reaction pathway reported in the literature. These elementary reaction steps were indicated to be energetically barrier-less. The formation of acrylonitrile over Te=O as the H abstraction site from the surface absorbed precursor was found to be a barrier-less step. The overall reaction pathway was then explored using micro-kinetic models to study the selectivity of propane ammoxidation to acrylonitrile on the Mo-V-Te-Nb-O M1 phase. The calculated coverages of surface intermediates on Mo and V active sites from the micro-kinetic model indicated that NH is the dominant species on the surface as compared to surface O species which may explain why the M1 phase is so selective in transforming the gas-phase p-allyl intermediate into acrylonitrile as opposed to combustion products. This thesis reports the very first theoretical study of a complete mechanism of propane ammoxidation over surface ab planes of bulk mixed Mo-V-Te-Nb-O M1 phase. Improved understanding of the surface structure - reactivity relationships for propane ammoxidation to acrylonitrile over this model mixed metal oxide system gained in this research offers a possibility of not only molecular engineering of such mixed metal oxide catalysts for propane (amm)oxidation, but also fundamentally advancing the field of selective alkane (amm)oxidation over bulk mixed metal oxides.
Book Synopsis Forcefield-based Simulations of Bulk Structure of Mo-V-(Te, Nb)-O M1 Phase Catalysts for Selective Propane Ammoxidation to Acrylonitrile by : Yaroslav A. Kapustin
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:
Book Synopsis Computational Materials, Chemistry, and Biochemistry: From Bold Initiatives to the Last Mile by : Sadasivan Shankar
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.
Book Synopsis Role of Constituent Elements in Propane Oxidation Over Mixed Metal Oxides by :
Download or read book Role of Constituent Elements in Propane Oxidation Over Mixed Metal Oxides written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently discovered multi-component Mo-V-Te-Nb-O catalysts contain so-called "M1" and "M2" phases with orthorhombic and hexagonal structures, respectively, proposed to be active and selective in propane (am)oxidation to acrylic acid and acrylonitrile. The elemental compositions, metal oxidation states and catalytic functions of V, Mo and Te in the surface region of the model orthorhombic (M1) Mo-V-Te-O system were examined employing low energy ion scattering and X-ray photoelectron spectroscopy. These findings suggested that the bulk Mo-V-Te-O structure functions as a special support for the unique active and selective surface monolayer in propane oxidation to acrylic acid. Propane oxidation to acrylic acid over pure phases indicated that M1 phase is the selective phase while M2 is the more active phase. The bulk Mo-V-O catalysts (orthorhombic phase) promoted with sub-monolayer quantities of surface Te, Nb and Sb oxides were further investigated to elucidate the roles of the constituent oxides in selective propane oxidation.
