Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Some Chemical and Structural Studies of Tin-molybdenum Oxide Catalysts
Author: Surface Science Studies of Model Oxide Catalysts
Author: Chanut BamroongwongdeePublisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 0
Book Description
Studies in Molybdenum Oxide Catalysts
Author: David Earl HuffmanPublisher:
ISBN:
Category : Molybdenum compounds
Languages : en
Pages : 334
Book Description
The cocondensation reactions of molybdenum trioxide vapor with tetraalkoxysilanes, trimethylalkoxysilanes, and hexamethyldisiloxane at -196°C were investigated. The products from the metal vapor reactions of tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane were characterized as molybdenum(VI)dioxodialkoxy compounds. The isolated compounds were found to be polymeric in the solid state by bridging through alkoxide groups. Metal vapor reaction of trimethylmethoxysilane gave an inseparable mixture of molybdenum(VI)alkoxysiloxy compounds which were also polymeric in nature. The metal vapor reactions of tetra-2-butoxysilane and trimethyl-t-butoxysilane gave butenes as a primary organic product and an uncharacterized blue molybdenum-containing solid. All products isolated in this study were sensitive to atmospheric moisture and light. The molybdenumdioxoalkoxy and molybdenumdioxoalkoxysiloxy compounds are good model compounds for the oxidation of alcohols. Decomposition studies of Mo(0)2(OMe)2 and Mo(0)2(OMe)x(OSiMe3)y yielded oxidation products of methanol, including dimethylether, formaldehyde, methyl formate, and dimethoxymethane. The reactivity of Mo(0)2(OEt)2 towards acidic protons was used to attach the molybdenum(VI)dioxo group to the surface of alumina (Al203), silica (Si02), titania (Ti02), zirconia (Zr02), and HY-zeolite. Chemical analysis and infrared spectroscopic studies indicate that dioxomolybdenum is attached to the support through bridging oxides between the support metal and molybdenum. The +2, +4, and +6 oxidation states of the surface attached molybdenum could be accessed by oxidation or reduction with 02 or H2, respectively. A survey of the catalytic nature for oxidation, metathesis, and Fischer- Tropsch synthesis of the supported molybdenum compounds in appropriate oxidation states was made. Dramatic differences in the activity and selectivity for oxidation of alcohols were observed depending on the support used. The Ti02 supported Mo(VI) showed the highest activity and selectivity for the oxidation of methanol to formaldehyde. The A1203 supported Mo(IV) system was the most active catalyst for propylene metathesis with the Si02 supported Mo(IV) system showing much less activity.
Molybdenum
Author: E.R. BraithwaitePublisher: Elsevier
ISBN: 1483290891
Category : Science
Languages : en
Pages : 681
Book Description
Molybdenum is an element with an extremely rich and interesting chemistry having very versatile applications in various fields of human activity. It is used extensively in metallurgical applications. Because of their anti-wear properties, molybdenum compounds find wide applications as lubricants - particularly in extreme or hostile environmental situations. Many molybdates and heteropolymolybdates are white and therefore used as pigments. In addition, they are non-toxic and act as efficient corrosion inhibitors and smoke suppressants. Hydroprocessing of petroleum is one of the largest industries employing heterogeneous catalysts. Molybdenum catalysts have shown great promise in the liquefaction of coal and this may develop into one of its most important catalytic uses. The use of molybdenum compounds in homogeneous catalysis is also significant. Three important classes of molybdenum compounds in the solid state are reviewed, viz., oxides, sulphides and halides. The role of molybdenum in inorganic catalysis and enzymes receives prominent mention because of their impact on the progress of science and technology. Further biochemical and enzymic factors are discussed in separate chapters and their reaction to agriculture and animal husbandry. A new classification of covalent compounds which abandons the traditional oxidation state concept allows a powerful approach to the organisation of the complex and rich chemistry of molybdenum. Dramatic colour diagrams of abundances of molybdenum compounds provide broad insights into the important features and trends in the chemistry of molybdenum including reactivity and mechanism. The book is intended for use mainly as a research monograph by the many workers who may encounter molybdenum chemistry or who are looking for its application and potential uses in different technological fields. However, it will also serve as an advanced text for university lecturers and postgraduate students interested in inorganic, physical and industrial chemistry, chemical technology or biochemistry and biotechnology.
Raman Spectroscopic Studies of Iron/molybdenum Oxide Catalysts for the Oxidation of Methanol to Formaldehyde
Author: James Harvey Wilson (III)Publisher:
ISBN:
Category : Formaldehyde
Languages : en
Pages : 396
Book Description
Preparation of Catalysts VII
Author: R. MaggiPublisher: Elsevier
ISBN: 0080539459
Category : Technology & Engineering
Languages : en
Pages : 1007
Book Description
The proceedings of the VIIth International Symposium on the Scientific Bases for the Preparation of Heterogeneous Catalysts, are in line with the general scope of this series of events. Emphasis in all Symposia has been on the scientific aspects of the preparation of new and industrial catalysts, or on new methods of preparation, rather than on the catalytic reactions in which such solids are ultimately used. In the present context, the catalytic event itself has only been considered as another, though often decisive, method of catalyst characterization.
Spillover and Mobility of Species on Solid Surfaces
Author: A. Guerrero-RuizPublisher: Elsevier
ISBN: 0080539742
Category : Technology & Engineering
Languages : en
Pages : 501
Book Description
"Spillover and Mobility of Species and Solid Surfaces" collects the papers which were presented at the Fifth International Conference Spillover, either as oral or poster contributions, as well as the summaries of the invited lectures. This congress and its publication in the Studies on Surface Science and Catalysis series follow the tradition of previous conferences on spillover, initiated in Lyon, 1983, and continued in Leipzig, 1989, Kyoto 1993 and Dalian, 1997. For the fifth conference, held in S.L. el Escorial (Madrid), the organising committee has attempted to compile representative contributions which illustrate the advances in understanding the spillover phenomenon since 1997. Spillover is a process taking place during the interface of gas reactant molecules (mainly hydrogen and oxygen) on solid surfaces. However, different contributions to the more general area of the chemistry at surfaces, related with the mobility and migration of species, diffusion through membranes, fuel cell catalysts, etc., have also been included. In fact the title of the present volume summarizes this attempt to extend the conference topics towards dynamics at surfaces.Among the 70 contributions received, the 56 accepted papers were selected on the basis of the reports of at least two international reviewers, according to standards comparable to those applied for other specialised journals. These papers are from 21 different countries.
In situ resonance raman studies of molybdenum oxide based selective oxidation catalysts
Author: Martin DieterleIn Situ Resonance Raman Studies of Molybdenum Oxide Based Selective Oxidation Catalysts
Author: Natural Gas Conversion VI
Author: T.H. FleischPublisher: Elsevier
ISBN: 0080537316
Category : Technology & Engineering
Languages : en
Pages : 577
Book Description
This volume contains peer-reviewed manuscripts describing the scientific and technological advances presented at the 6th Natural Gas Conversion Sumposium held in Alaska in June 2001. This symposium continues the tradition of excellence and the status as the premier technical meeting in this area established by previous meetings.The 6th Natural Gas Conversion Symposium is conducted under the overall direction of the Organizing Committee. The Program Committee was responsible for the review, selection, editing of most of the manuscripts included in this volum. A standing International Advisory Board has ensured the effective long-term planning and the continuity and technical excellence of these meetings.