Download or read book Synthesis Methodology Affecting Vanadium Titanium Silicalite 1 Catalyst written by and published by . This book was released on 2006 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vanadium titanium silicalite-1 (V/TS-1) samples (Si/Ti = 50, Si/V = 100) are synthesized by using hydrothermal method. To determine a suitable synthesis method that can control the amounts of titanium and vanadium in the MFI structure of synthesized catalysts, the effects of synthesis methodology (the vanadium salt addition method) and type of vanadium salt (VCl[subscript 3], VO(acac)[subscript 2] and V[subscript2]O[subscript 5] ) are investigated. The synthesized catalysts are characterized using various techniques such as XRF, XRD, BET, SEM, FT-IR, NH -TPD and ESR. The catalytic behavior is evaluated using the gas phase oxidation of 2-propanol (8 vol% oxygen, 5 vol% 2-propanol, balanced with argon). The catalytic reaction is carried out in a microreactor at a temperature range 100-500 degree Celsius, atmosphere pressure. This research shows that the vanadium salt addition method and the type of vanadium salt do not significantly affect the MFI structure as well as the reaction pathway. During the synthesis procedure, the vanadium species existing in the part of cation complex when it dissolved in aqueous solution is easier to be incorporated into the TS-1 structure than the ones exist in the part of anion complex. The surface area of the synthesized catalysts decrease inversely with the amount of vanadium incorporated. The NH[subscript 3] -TPD results indicate that the synthesized catalysts have two different types of acid site; the weaker one desorbed NH[subscript 3] at the temperature range 135-145 degree Celsius and the stronger one desorbed NH [subscript 3] at around 222-242 degree Celsius. For catalytic behavior, it is found that the synthesized V/TS-1 catalysts which have the vanadium active species derived from VCl [subscript 3] bonded on its surface are active in the 2-propanol oxidation and it can inhibit the dehydration and the combustion of 2-propanol. However, the ones which have the vanadium active species derived from VO(acac)[subscript 2] bonded on the catalyst surface do not be active in the 2-propanol oxidation but it can inhibit the 2-propanol combustion. Moreover, it is found that V[subscript 2]O[subscript 5] is not the suitable vanadium source for this synthesis method because V[superscript 5+] tends to stay in the anion complex which is more difficult to be incorporated into the TS-1 structure.

Download or read book Synthesis Methodology Affecting Chromium titanium Silicalite 1 Catalyst written by Em-orn Phromphet and published by . This book was released on 2006 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research focuses on the synthesis methodology (i.e. the chromium salt addition method) affecting the chromium-titanium silicalite-1 catalyst synthesized by hydrothermal method. The effect of using different kinds of chromium salt (i.e. Cr(NO[subscript3]) [subscript3].9H[subscript2]O and CrO[subscript3]) is also investigated. All synthesized catalysts are characterized using various techniques consisting of XRF XRD BET SEM FT-IR ESR and NH[subscript3]-TPD. The catalytic behavior of the synthesized catalysts is tested by the gas phase oxidation of 2-propanol in a fixed bed reactor at the reaction temperature range 100-500 degrees celsius, atmospheric pressure. The composition of the feed is 5% 2-propanol, 8% oxygen by volume and balanced with argon. The results show that the chromium salt addition method and the kind of chromium salt affect the amount of chromium incorporated into TS-1 structure. Moreover, it is found that the synthesized catalysts have various shapes but their MFI structures are maintained. The ESR results indicate that some synthesized catalysts consist of Cr[superscript5+] bonded in octahedral from outside the framework structure. The NH[subscript3]-TPD results report that the synthesized catalysts have two different types of acid strength, the weaker one desorbs NH[subscript3] at 137-149 degrees celsius and the stronger one desorbs NH[subscript3] at 224-247 degrees celsius. The catalytic behavior does not depend on the amount of incorporated chromium. Therefore, the catalytic activities over all synthesized catalysts and over TS-1 are similar.

Download or read book Catalytic Study of Iron Aluminium Cobalt and Vanadium Modified Titanium Silicalites 1 in the Hydroxylation of Benzene to Phenol by Hydrogen Peroxide written by and published by . This book was released on 2006 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research has studied the catalytic activity of titanium silicalite-1 (TS-1) catalysts modified by Fe Al Co and V were synthesized, characterized and tested in the hydroxylation of benzene by hydrogen peroxide and the effects of pretreatment with nitric acid aqueous solution on the catalytic activity of catalysts. The results of the reaction show that the Fe Al Co and V incorporated in TS-1 framework promoted the catalytic activity higher than TS-1. Especially, the Co-TS-1 catalyst has the highest catalytic activity. After the catalysts were pretreated by nitric acid aqueous solution, the framework structure of catalyst is not destroyed and titanium in the framework is not removed. But, the extra-framework can be removed partly. As a result, the activity of the pretreated catalysts is improved. The catalytic activity of the investigated catalyst is in the following order Co-TS-1 > V-TS-1 > Fe-TS-1 > A1-TS-1 > TS-1. Co-TS-1 is found to be the best one due to it cause the lowest H[subscript2]O[subscript2] decomposition and has the least phenol product deposite on the surface.

Download or read book Preparation of Cobalt Titanium Silicalite 1 Catalyst written by Nitiporn Sangngaen and published by . This book was released on 2005 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium silicalite incorporated with various content of cobalt was synthesized by the hydrothermal method. The synthesized catalyst (Co-TS-1) were characterized by various techniques XRF, BET, XRD, FT-IR, SEM, XPS and NH[subscript 3]-TPD, to study the effects of cobalt on the formation of titanium silicalite crystal. The oxidation properties of Co-TS-1 catalysts were investigated by using the gas phase oxidation reaction of 2-propanol as the test reaction. The study reveals that the maximum amount of cobalt which can be incorporated into the TS-1 structure without any interference to the main TS-1 structure is about 0.38 mol%. The analysis by XPS reveals that the oxidation state of cobalt cation in the TS-1 framework is +2. In addition, the incorporation of cobalt increases the amount of the weak acid site while the amount of the strong acid site decreases. The Co-TS-1 catalysts exhibit higher catalytic activity for the dehydration reaction than theunmodified TS-1 was also found that the selectivity toward propylene of Co-TS-1 is also higher than that of the unmodified TS-1.

Download or read book Synthesis Characterization and Catalytic Properties of Titanium silicalite 1 written by Diana Huybrechts and published by . This book was released on 1991 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bifunctional Oxidative and Acidic Titanium Silicalite TS 1 Catalysts for One Pot Synthesis of 1 2 octanediol from 1 octene written by Didik Prasetyoko and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Synthesis Characterization and Catalytic Properties of Titanium and Vanadium Aluminophosphate Molecular Sieves written by Mohammad Hassan Zahedi-Niaki and published by . This book was released on 1999 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vanadium and Titanium Containing Molecular Sieves written by Marcello Stefano Rigutto and published by . This book was released on 1996 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Novel Single site Titanosilicates with Targeted Connectivities and Geometries as Selective Oxidation Catalysts written by Lena Elenchin and published by . This book was released on 2017 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary focus of this research was to synthesize and characterize two families of titanosilicate catalysts, first generation and second generation, that were single site, atomically dispersed with targeted connectivities to the silicate matrices but had different geometries about the active sites. First generation catalysts have tetrahedral active sites, while second generation catalysts have altered geometries for a more accessible active site, but maintain the same targeted connectivities. A building block methodology is employed to prepare single site, isolated, atomically dispersed titanium active sites within a silicate matrix. The synthetic approach uses a molecular precursor, i.e., building block and the method of sequential additions to construct the support matrix around the active site. This methodology can be used to target titanium connectivities (2, 3, or 4 linkages) to the matrix, namely 2-connected (2C-), 3-connected (3C-Ti) and 4-connected (4C-Ti) Several characterization techniques are used to compare and contrast first and second generation catalysts; NMR, gravimetric analysis (determine connectivity), FTIR, XAS (XANES/EXAFS), DRUV, and catalytic activity are used to characterize the final catalysts. Based on spectroscopic characterization, two families of catalysts with different geometries were successfully synthesized. Catalytic studies showed two distinct relationships could be made: 1) The activities of these catalysts correlate with the connectivity of the titanium site as long as leaching does not occur. 4C-Ti catalysts were less active than 3C-Ti catalysts. The 2C-Ti catalysts leached from the support matrix and therefore cannot be considered true heterogeneous catalysts. 2) Second generation catalysts were more active than first generation catalysts due to the more open geometry of the active site.

Download or read book The Activation of Dioxygen and Homogeneous Catalytic Oxidation written by D.H.R. Barton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph consists of the proceedings of the Fifth International Symposium on the Activation of Dioxygen and Homogeneous Catalytic Oxidation, held in College Station, Texas, March 14-19, 1993. It contains an introductory chapter authored by Professors D. H. R. Barton and D. T. Sawyer, and twenty-nine chapters describing presentations by the plenary lecturers and invited speakers. One of the invited speakers, who could not submit a manuscript for reasons beyond his control, is represented by an abstract of his lecture. Also included are abstracts of forty-seven posters contributed by participants in the symposium. Readers who may wish to know more about the subjects presented in abstract form are invited to communicate directly with the authors of the abstracts. This is the fifth international symposium that has been held on this subject. The first was hosted by the CNRS, May 21-29, 1979, in Bendor, France (on the Island of Bandol). The second meeting was organized as a NATO workshop in Padova, Italy, June 24-27, 1984. This was followed by a meeting in Tsukuba, Japan, July 12-16, 1987. The fourth symposium was held at Balatonfured, Hungary, September 10-14, 1990. The sixth meeting is scheduled to take place in Delft, The Netherlands (late Spring, 1996); the organizer and host will be Professor R. A. Sheldon.

Download or read book Oxidation of N hexane Over Titanium Silicalite TS 1 Catalyst optimisation Studies written by Bhatia Subhash and published by . This book was released on 1996 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium silica (TS-1) is reported to be remarkable shape selective oxidation catalyst for the oxidation of organic substrates with dilute hydrogen peroxide as oxidant. The oxidation process over TS-1 is advantageous from an environmental point of view, as the side product is water. Hexanol and hexanone are important intermediates in many chemical processes. Oxidation of n-hexane with hydrogen peroxide over TS-1 catalyst were studied using acetone....

Download or read book Process and Chemical Engineering written by and published by . This book was released on 1997 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structure and Reactivity of Metals in Zeolite Materials written by Joaquín Pérez Pariente and published by Springer. This book was released on 2018-09-12 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides the reader with the most up-to-date and relevant knowledge on the reactivity of metals located in zeolite materials, either in framework or extra-framework positions, and the way it is connected with the nature of the chemical environment provided by the host. Since the first report of the isomorphous substitution of titanium in the framework of zeolites giving rise to materials with unusual catalytic properties, the incorporation of many other metals have been investigated with the aim for developing catalysts with improved performance in different reactions. The continuous expansion of the field, both in the variety of metals and zeolite structures, has been accompanied by an increasing focus on the relationship between the reactivity of metal centers and their unique chemical environment. The concepts covered in this volume are of interest to people working in the field of inorganic and physical chemistry, catalysis and chemical engineering, but also for those more interested in theoretical approaches to chemical reactivity. In particular the volume is useful to postgraduate students conducting research in the design, synthesis and catalytic performance of metal-containing zeolites in both academic and application contexts.

Download or read book Verified Synthesis of Zeolitic Materials written by H. Robson and published by Gulf Professional Publishing. This book was released on 2001-06-26 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zeolite synthesis is an active field of research. As long as this continues, new phases will be discovered and new techniques for preparing existing phases will appear. This edition of Verified Synthesis of Zeolitic Materials contains all the recipes from the first edition plus 24 new recipes. Five new introductory articles have been included plus those from the first edition, some of which have been substantially revised. The XRD patterns have been recorded using different instrument settings from those in the first edition and are intended to conform to typical X-ray diffraction practice. In most cases, only the XRD pattern for the productas synthesised is printed here. The exceptions are those phases which show marked changes in the XRD pattern upon calcination.

Download or read book Supported Catalysts and Their Applications written by David C Sherrington and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need to improve both the efficiency and environmental acceptability of industrial processes is driving the development of heterogeneous catalysts across the chemical industry, including commodity, specialty and fine chemicals and in pharmaceuticals and agrochemicals. Drawing on international research, Supported Catalysts and their Applications discusses aspects of the design, synthesis and application of solid supported reagents and catalysts, including supported reagents for multi-step organic synthesis; selectivity in oxidation catalysis; mesoporous molecular sieve catalysts; and the use of Zeolite Beta in organic reactions. In addition, the two discrete areas of heterogeneous catalysis (inorganic oxide materials and polymer-based catalysts) that were developing in parallel are now shown to be converging, which will be of great benefit to the whole field. Providing a snapshot of the state-of-the-art in this fast-moving field, this book will be welcomed by industrialists and researchers, particularly in the agrochemicals and pharmaceuticals industries.

Download or read book Liquid Phase Oxidation via Heterogeneous Catalysis written by Mario G. Clerici and published by John Wiley & Sons. This book was released on 2013-04-26 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sets the stage for environmentally friendly industrial organic syntheses From basic principles to new and emerging industrial applications, this book offers comprehensive coverage of heterogeneous liquid-phase selective oxidation catalysis. It fully examines the synthesis, characterization, and application of catalytic materials for environmentally friendly organic syntheses. Readers will find coverage of all the important classes of catalysts, with an emphasis on their stability and reusability. Liquid Phase Oxidation via Heterogeneous Catalysis features contributions from an international team of leading chemists representing both industry and academia. The book begins with a chapter on environmentally benign oxidants and then covers: Selective oxidations catalyzed by TS-1 and other metal-substituted zeolites Selective catalytic oxidation over ordered nanoporous metallo-aluminophosphates Selective oxidations catalyzed by mesoporous metal-silicates Liquid phase oxidation of organic compounds by supported metal-based catalysts Selective liquid phase oxidations in the presence of supported polyoxometalates Selective oxidations catalyzed by supported metal complexes Liquid phase oxidation of organic compounds by metal-organic frameworks Heterogeneous photocatalysis for selective oxidations with molecular oxygen All the chapters dedicated to specific types of catalysts follow a similar organization and structure, making it easy to compare the advantages and disadvantages of different catalysts. The final chapter examines the latest industrial applications, such as the production of catechol and hydroquinone, cyclohexanone oxime, and propylene oxide. With its unique focus on liquid phase heterogeneous oxidation catalysis, this book enables researchers in organic synthesis and oxidation catalysis to explore and develop promising new catalytic materials and synthetic routes for a broad range of industrial applications.