Download or read book Concerning the Catalytic Activity of Metallic Oxides and Salts in Vapor Phase Oxidation written by Ralph Anderson Davis and published by . This book was released on 1942 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Catalytic Activity of Certain Metals and Metallic Oxides written by Harvey Day Royce and published by . This book was released on 1924 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Oxides written by J.L.G. Fierro and published by CRC Press. This book was released on 2005-08-24 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemistry of metals has traditionally been more understood than that of its oxides. As catalytic applications continue to grow in a variety of disciplines, Metal Oxides: Chemistry and Applications offers a timely account of transition-metal oxides (TMO), one of the most important classes of metal oxides, in the context of catalysis. The
Download or read book Transition Metal Oxides written by H.H. Kung and published by Elsevier. This book was released on 1989-04-01 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Catalytic Oxidation of Organic Compounds in the Vapor Phase written by Leroy Frank Marek and published by . This book was released on 2013-06 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additional Contributors Include Harrison E. Howe, S. C. Lind, Walter A. Schmidt, And Others.
Download or read book A Study of Vapor Phase Oxidation of Organic Compounds written by Ford Raphael Lowdermilk and published by . This book was released on 1930 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Catalytic Activity of Metal Oxides on Thermal Decomposition Reactions written by Eli S. Freeman and published by . This book was released on 1967 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of a selected series of solid metal oxides on the catalysis of the thermal decomposition of potassium chlorate and potassium perchlorate were investigated. The kinetics and rate parameters of the catalyzed decomposition reactions were studied and compared to the rate parameters observed in the absence of the solid oxides. Two oxides were selected for more precisely correlating the relationships between the electronic defect structure of the oxides and their catalytic behavior. The oxides investigated from this point of view were: ferric oxide and magnesium oxide. These oxides were doped with selected altervalent cation impurities, and heat treated at temperatures ranging from 700 to 1000 degrees C in oxygen and inert gas environment in order to introduce electronic defects. In addition, changes in catalytic activity in relationship to electronic changes as a result of exposure to Cobalt (60) gamma rays were investigated. The changes in semiconducting properties were studied and the results correlated with the changes in catalytic activity. A mechanism of decomposition of potassium chlorate is discussed as well as a proposed mechanism for the interaction of sulfur and potassium chlorate. (Author).
Download or read book The Catalytic Oxidation of Organic Compounds in the Vapor Phase written by Leroy Frank Marek and published by . This book was released on 1932 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book One dimensional 1 D Nanostructured Metal Oxides for Catalytic Oxidation of Hydrocarbons written by Yunzhe Feng and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic oxidation of hydrocarbons has been intensively studied, with the purpose of minimizing emissions of pollutants and facilitating the combustion process. Noble metals, such as platinum and palladium, are the most effective catalysts for the oxidation of hydrocarbons. However, the limited supply of these noble metals imposes a need for developing alternative catalysts. Transition metal oxides are attractive alternatives due to their high thermal stability and low cost. Previous studies of metal oxide catalysts have focused on metal oxide nanoparticles (NPs) supported on porous substrates, such as Al2O3, ZrO2 and spinel-type (AB2O4) supports. Although the dispersed metal species over large surface area have shown much higher activity than the bulk metal oxide, there are several limitations. First, interactions between the support and NPs at high temperatures impede the fundamental understanding of the catalytic properties of individual NPs, and limit their application conditions. Moreover, the solid supports limit the loading of NPs because NPs tend to aggregate at large loadings, leading to a decrease in catalytic activity. Herein, one-dimensional (1-D) nanostructured metal oxide were directly grown on metal mesh substrates and used as catalysts for hydrocarbons oxidation. The 1-D nanostructured catalysts benefits from reduced interaction with the substrates, great flexibility in increasing the catalyst loading, and convenience in tuning the surface chemistry for higher catalytic activity, thus exhibit comparable or better catalytic activity and stability compared to the supported NPs. As one of the most active metal oxide catalysts, CuO was used as a model system to demonstrate the effectiveness of the 1-D nanostructured metal oxide catalysts. CuO NWs have been grown on Cu mesh by solid phase diffusion and applied to catalyze methane oxidation reactions. The CuO NWs have shown comparable or even better activity and stability than the supported CuO NPs. Moreover, owing to the fact that the NWs were exposed on the substrate surface and easy to access, two methods were used to tune the NWs for enhanced catalytic activity. The first one was to reduce the CuO NWs to more active Cu2O NWs by H2 plasma, which has shown 20% increase activity for CH4 oxidation reactions and several times higher activity for CO oxidation reactions. The kinetics study have shown that the bulk oxygen diffusion in Cu2O was faster, which could be one of the reasons for higher activity of Cu2O than that of CuO. The second tuning method was to decorate the CuO NWs with more active NP materials, such as Co3O4 and noble metals with a newly developed simple, fast and general sol-flame method. After the Co3O4 decoration, the CuO NWs surface was uniformly and densely covered by Co3O4 NP-chain structures, with large NP loading, high surface area and minimal aggregation, resulting in times higher activity in catalyzing CH4 oxidation. Moreover, this sol-flame method is a general method to decorate NWs with various NPs, and even to dope NWs with dopants for desirable properties. Given the generality and simplicity of the sol-flame methods, it can be applied to not only catalysis, but also other important application areas, such as lithium ion battery, supercapacitor and photoelectrochemical devices. In addition, to incorporate Cu and Co, the most active metal oxide catalyst Co3O4 was grown as 1-D structure on stainless steel mesh with the Cu2+ ion enhanced ammonia-evaporation-induced synthesis method. The synergetic effects of Cu and Co in catalytic process were studied, which have shown that the Cu2+ improved the nucleation and growth process of 1-D Co3O4, however, the catalytic activity is mainly from the Co species.
Download or read book Catalytic Reduction in the Vapor Phase written by Frank B. Kitchel and published by . This book was released on 1941 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding the Catalytic Activity of Oxides Through Their Electronic Structure and Surface Chemistry written by Kelsey Ann Stoerzinger and published by . This book was released on 2016 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intermittent nature of renewable energy sources requires a clean, scalable means of converting and storing energy. Water electrolysis can sustainably achieve this goal by storing energy in the bonds of oxygen and hydrogen molecules. The efficiency of this storage-conversion process is largely determined by the kinetic overpotential required for the oxygen evolution and reduction reactions (OER and ORR), respectively. This thesis focuses on transition metal oxides as alternative oxygen catalysts to costly and scarce noble metals. In order to develop descriptors to improve catalytic activity, thus reducing material cost for commercial technologies, this work studies fundamental processes that occur on model catalyst systems. Electrochemical studies of epitaxial oxide thin films establish the intrinsic activity of oxide catalysts in a way that cannot be realized with polydisperse nanoparticle systems. This thesis has isolated the activity of the catalyst on a true surface-area basis, enabling an accurate comparison of catalyst chemistries, and also revealed how different terminations and structures affect the kinetics. These studies of epitaxial thin films are among the first to probe phenomena that are not straightforward to isolate in nanoparticles, such as the role of oxide band structure, interfacial charge transfer (the "ligand" effect), strain, and crystallographic orientation. In addition, these well-defined surfaces allow spectroscopic examinations of their chemical speciation in an aqueous environment by using ambient pressure X-ray photoelectron spectroscopy. By quantifying the formation of hydroxyl groups, we compare the relative affinity of different surfaces for this key reaction intermediate in oxygen electrocatalysis. The strength of interaction with hydroxyls correlates inversely with activity, illustrating detrimental effects of strong water interactions at the catalyst surface. This fundamental insight brings molecular understanding to the wetting of oxide surfaces, as well as the role of hydrogen bonding in catalysis. Furthermore, understanding of the mechanisms of oxygen electrocatalysis guides the rational design of high-surface-area oxide catalysts for technical application.
Download or read book The Catalytic Vapor phase Oxidation of Some Four carbon Hydrocarbons written by Randolph H. Bretton and published by . This book was released on 1949 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Surface Structure on the Catalytic Activity of Alumina Supported Transition Metal Oxides written by Paul Worn Park and published by . This book was released on 1996 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Activities of Metal Oxides and Some Vanadate Salts in the Vapor Phase Reduction of 1 nitronaphthalene written by Ray Clifford Christena and published by . This book was released on 1951 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Oxidation in the Vapor Phase written by Henry Dorroh Foster and published by . This book was released on 1937 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Catalytic Vapor phase Oxidation of Some Four carbon Hydrocarbons written by Randolph Henry Bretton and published by . This book was released on 1952 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toward a Molecular Level Understanding of Mixed Metal Oxide Oxidation Catalysts written by Andrew Getsoian and published by . This book was released on 2013 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: The selective oxidation and ammoxidation of light olefins comprises a 5 million ton per year industry, and is responsible for making possible products from nitrile rubber to Plexiglas to acrylic paint. The industrial catalyst of choice for such reactions is based on bismuth molybdate, and was first patented in the 1950s. In the intervening decades, a significant body of research has been done on bismuth molybdate-based catalysts, and yet a surprising amount is still not known about how these catalysts work. This Thesis has focused primarily on developing new methods for studying bismuth molybdates and related catalysts in order to gain new insight into the means by which the physical and electronic structures of the active sites in these catalysts give rise to their catalytic activity. The mechanism by which propene is oxidized on the (010) surface of Bi2Mo3O12 has been investigated using the RPBE+U variety of density functional theory (DFT). The location of the active site was determined, and the calculated barrier for the rate-determining step at this site found to be in good agreement with experimental results. Calculations revealed the essential roles of bismuth and molybdenum in providing the geometric and electronic structure responsible for catalytic activity at the active site, and suggested that catalytic activity could be further enhanced by substitution with a more reducible element. In order to accurately model substitution of an additional reducible element in to Bi2Mo3O12 using DFT, more sophisticated approaches than RPBE+U were required. Two more advanced density functionals, M06-L and HSE, were examined. The HSE functional was found to be too expensive for practical use on extended systems like bismuth molybdate catalysts. The accuracy of the M06-L functional for lattice constants and geometries, reaction energies and barriers, electronic structures, and non-covalent interactions was investigated, and compared results from the RPBE+U method. The M06-L functional was found to be superior to RPBE+U for lattice constants, reaction energies, and non-covalent interactions, and as good as or better than RPBE+U for electronic structures. Use of the M06-L functional was therefore determined to be preferable to use of RPBE+U for use in the study of substituted bismuth molybdate catalysts. Calculations employing the M06-L functional were combined with physical characterization using diffuse reflectance UV-VIS, x-ray photoelectron, and x-ray near edge absorption spectroscopies in order to understand the effect of substitution of vanadium for molybdenum on the activation energy for propene oxidation in catalysts of formula Bi1-x/3V1-xMoxO4. In these catalysts, substitution of vanadium for molybdenum has been observed to lower the apparent activation barrier for propene oxidation. It was found that the lower activation barrier for propene oxidation over mixed vanadate-molybdate catalysts is a consequence of the smaller difference between the catalyst conduction band edge energy and the energy level of the highest occupied molecular orbital in propene. The lower conduction band edge energy in mixed vanadate-molybdate catalysts is related to the energies of and degrees of mixing between the V 3d and Mo 4d orbitals comprising the conduction band. Both of these observations suggest general principles that may be of relevance to a variety of mixed metal oxide catalyst systems. An improved procedure for synthesizing bismuth molybdate and bismuth vanadate catalysts was also developed. This procedure involved a two step templating process: a structured mesoporous carbon was templated from KIT-6 or MCM-48 mesoporous silica, and the structured mesoporous carbon in turn used as a template during synthesis of the metal oxide catalyst. Catalysts produced by the double templating process had surface areas of 14-17 m2/g, a large improvement on the
