Download or read book Metal Cluster Hydrodesulfurization Catalysts Based on Ternary Molybdenum Sulfides written by Robert Kirk Thompson and published by . This book was released on 1999 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Temperature-programmed analysis studies were performed in conjunction with XPS to examine how the oxidation states change as a function of pretreatment temperature. The mechanism through which these new reduced ternary molybdenum sulfides convert to the crystalline Chevrel phase was also determined. The low temperature synthesis route of these new reduced molybdenum sulfides has allowed the synthesis of new cluster compounds, such as Pt(Mo6S)S. X-ray photoelectron spectroscopy, laser Raman spectroscopy, infrared spectroscopy and microprobe analysis indicate that this new material is structurally similar to other cluster compounds we have synthesized. Pretreatment of PtMoS in hydrogen at 950°C results in its conversion to the previously unknown crystalline Chevrel phase.

Download or read book Reduced Ternary Molybdenum and Tungsten Sulfides and Hydroprocessing Catalysis Therewith written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New amorphous molybdenum/tungsten sulfides with the general formula M.sup.n+.sub.2x/n (L.sub.6 S.sub.8)S.sub.x, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M.sub.6 S.sub.8).sup.0 cluster units are present. Vacuum thermolysis of the amorphous Na.sub.2x (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH first produces poorly crystalline NaMo.sub.6 S.sub.8 by disproportionation at 800.degree. C. and well-crystallized NaMo.sub.6 S.sub.8 at .gtoreq. 900.degree. C. Ion-exchange of the sodium material in methanol with soluble M.sup.2+ and M.sup.3+ salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M.sup.n+.sub.2x/n (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M.sup.n+.sub.2x/n Mo.sub.6 S.sub.8+x (MeOH).sub.y>MMOS! (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as "Chevrel phase-like" in that both contain Mo.sub.6 S.sub.8 cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst showed to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS.sub.2 catalysts.

Download or read book Ternary Molybdenum Chalcogenide Catalysts for Hydrodesulfurization written by Sulyman Age Kareem and published by . This book was released on 1988 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrodesulfurization Catalysis and Mechanism of Supported Transition Metal Sulfides written by Emiel Jan Maria Hensen and published by . This book was released on 2000 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrodesulfurization Catalysis by Chevrel Phase Compounds written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A process is disclosed for the hydrodesulfurization of sulfur-containing hydrocarbon fuel with reduced ternary molybdenum sulfides, known as Chevrel phase compounds. Chevrel phase compounds of the general composition M.sub.x Mo.sub.6 S.sub.8, with M being Ho, Pb, Sn, Ag, In, Cu, Fe, Ni, or Co, were found to have hydrodesulfurization activities comparable to model unpromoted and cobalt-promoted MoS.sub.2 catalysts. The most active catalysts were the "large" cation compounds (Ho, Pb, Sn), and the least active catalysts were the "small" cation compounds (Cu, Fe, Ni, Co.).

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsupported Transition Metal Sulfide Catalysts for Deep Hydrodesulfurization of Hydrocarbon Fuels written by and published by . This book was released on 2007 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: The requirement of clean fuels has resulted in a continuing worldwide effort to dramatically reduce the sulfur levels. This is driving the need for more active hydrodesulfurization (HDS) catalysts. The purpose of this research is to study the potential of unsupported Mo based sulfide catalysts prepared from hydrothermal method. The unsupported catalysts exhibited the excellent activity for the simultaneous HDS of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Activity and surface area of catalysts depend strongly upon the preparation temperature and pressure. Organic solvent added in catalyst preparation helps to improve the dispersion of the precursor molecules. The unpromoted and promoted (Co or Ni) Mo sulfide catalysts have different properties and activity. Addition of promoter decreased surface area and pore volume. TPR analysis suggested that promoter decrease metal sulfur bond strength. HRTEM and XRD results showed that the growth of catalyst particle was suppressed when promoter was added. The promoter increased HDS activity of MoS[subscript 2] and changed the contribution of the direct-desulfurization and of hydrogenation pathways. The main effect of the promoter was to increase the rate of C-S bond cleavage. The liquid-phase adsorption of DBT and 4,6-DMDBT was used to study the adsorption capacity and mechanism over the synthesized catalysts. The results showed that the promoters not only increase active site number, but also enhance activity of active sites of the Mo sulfide.

Download or read book Carbon supported Iron and Iron molybdenum Sulfide Catalysts written by Wilhelmus Leonardus Timotheus Maria Ramselaar and published by . This book was released on 1988 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 8th International Congress on Catalysis Impact of surface science on catalysis structure selectivity written by and published by . This book was released on 1984 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1976 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon supported Iron and Iron molybdeneum Sulfide Catalysts written by Wilhelmus Leonardus Timotheus Maria Ramselaar and published by . This book was released on 1988 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chalcogenide Materials for Energy Conversion written by Nicolas Alonso-Vante and published by Springer. This book was released on 2018-04-20 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses electrocatalysis based on chalcogenides, particularly in the nanoscale domain. Special attention is paid to the hydrogen evolution reaction (HER) and the oxygen reduction reaction (ORR). The book provides an introduction to materials synthesis; the basic principles of electrocatalysis; related precious metal versus non-precious metal catalytic center chalcogenides as well as supports; and the role of such supports in stabilizing the catalytic centers. In short: pursuing a bottom-up approach, it covers the properties of this class of electrocatalysts and examines their applications in low-temperature fuel systems such as microfluidic fuel cells for portable devices. Accordingly, it is ideally suited for all professionals and researchers interested in electrochemistry, renewable energy and electrocatalysis, and non-precious metal centers for chemical energy conversion.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1985 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Single layer Transition Metal Sulfide Catalysts written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition Metal Sulfides (TMS), such as molybdenum disulfide (MoS.sub.2), are the petroleum industry's "workhorse" catalysts for upgrading heavy petroleum feedstocks and removing sulfur, nitrogen and other pollutants from fuels. We have developed an improved synthesis technique to produce SLTMS catalysts, such as molybdenum disulfide, with potentially greater activity and specificity than those currently available. Applications for this technology include heavy feed upgrading, in-situ catalysis, bio-fuel conversion and coal liquefaction.

Download or read book Electrochemistry of Metal Chalcogenides written by Mirtat Bouroushian and published by Springer Science & Business Media. This book was released on 2010-04-23 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author provides a unified account of the electrochemical material science of metal chalcogenide (MCh) compounds and alloys with regard to their synthesis, processing and applications. Starting with the chemical fundamentals of the chalcogens and their major compounds, the initial part of the book includes a systematic description of the MCh solids on the basis of the Periodic Table in terms of their structures and key properties. This is followed by a general discussion on the electrochemistry of chalcogen species, and the principles underlying the electrochemical formation of inorganic compounds/alloys. The core of the book offers an insight into available experimental results and inferences regarding the electrochemical preparation and microstructural control of conventional and novel MCh structures. It also aims to survey their photoelectrochemistry, both from a material-oriented point of view and as connected to specific processes such as photocatalysis and solar energy conversion. Finally, the book illustrates the relevance of MCh materials to various applications of electrochemical interest such as (electro)catalysis in fuel cells, energy storage with intercalation electrodes, and ion sensing.

Download or read book Ligated Transition Metal Clusters in Solid state Chemistry written by Jean-François Halet and published by Springer Nature. This book was released on 2019-08-29 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume dedicated to the memory of Marcel Sergent who was a leader in this field for many years, addresses past achievements and recent developments in this vibrant area of research. Large classes of ligated transition metal clusters are produced either exclusively or most reliably by means of high-temperature solid-state reactions. Among them, the Chevrel-Sergent phases and related materials have generated enormous interest since their discovery in 1971. Today, these materials and their numerous derivatives still constitute a vivid area of research finding some applications not only in superconductivity, but also in catalysis, optics or thermoelectricity to mention a few.