DOCSLIB.ORG

79943 IMOA News-July05

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
79943 IMOA News-July05 R NEWSLETTER INTERNATIONAL MOLYBDENUM ASSOCIATION JULY 2005 17th Annual General Meeting This event will be kindly hosted in Shanghai by Jinduicheng Molybdenum Mining Corp, owners of the largest moly mine in China, during the week beginning 12 September 2005. Non-members wishing to attend should contact the Secretariat for further details. HSE Management The focus on HSE by regulatory authorities affects all metals and IMOA is not alone in spending an increasing amount of time and money to ensure that the industry it represents is ready to respond with facts and figures. IMOA has appointed a team (see photo) to implement its work programme. Sandra Carey, who has been connected with moly and IMOA for many years, will direct our activities; and technical support will be provided by Wieslaw Piatkiewicz who is employed by the Galvanizers Association and whose expertise in risk assessment will be invaluable. IMOA’s HSE Management Team: Sandra Carey and To most of our readers, neither will need any introductions. Wieslaw Piatkiewicz Both may be contacted via the IMOA office. Chemical Applications Membership of Molybdenum IMOA has tended to focus its market moly industry since the mid-1960s Welcome to: development work programme on and is a part-time consultant to metallurgical applications since these IMOA. He is responsible for comprise some 80% of moly usage compiling the Database "Mo in ■ JSC Polema Corp, and appear to offer the greatest scope Relation to Health, Safety and the for increasing moly consumption. Environment", which may be accessed a Russian company manufacturing on our website. This Newsletter comprehensively metal powders. Its product range remedies the fact that an article on The article which follows is an chemical applications is long overdue. adapted version of the paper he comprises more than 500 presented in an entertaining fashion (not easy with all those complicated molybdenum product items The author, Philip Mitchell, is Emeritus Professor of Chemistry at bonds and formulae) at the including large sized high purity the University of Reading in the Association’s Annual General UK;he has been associated with the Meeting in 2004. (99.90-99.96%) molybdenum INTERNATIONAL MOLYBDENUM ASSOCIATION sputtering targets and 2 Baron’s Gate, 33 Rothschild Road, London W4 5HT, UK Tel: +44 20 8742 2274 Fax: + 44 20 8742 7345 molybdenum metal powder. email: [email protected] www.imoa.info Chemical Applications of Molybdenum Understanding molybdenum chemistry and applications Philip C.H. Mitchell School of Chemistry, University of Reading, Reading RG6 6AD, UK Molybdenum Table 1 Some Uses of Molybdenum Compounds Compounds and Applications catalysts MoO3, molybdates, e.g. iron and bismuth molybdates molybdenum disulfide The purpose of this article is to describe the technical applications of lubricants molybdenum disulfide molybdenum compounds and the molybdenum-sulfur complexes, e.g with – underlying chemistry. Important, i.e. dithiocarbamate (R2NCS2 ) and dithiophosphate – higher volume, applications are listed ((RO)2PS2 ). in Table 1. These applications have been known for many years and are corrosion inhibitors sodium molybdate well established. Research in this area is about improving performance and paints, and surface coatings molybdates, e.g. zinc molybdate developing understanding of how the smoke suppressors MoO3, ammonium octamolybdate compounds work. Molybdenum compounds account for ca 20% of pigments ammonium and alkylammonium octamolybdates, molybdenum usage with catalysts the major application. Recent usage data for phosphomolybdic acid the United States are shown in ceramics molybdenum disilicide Fig. 1. nanomaterials molybdenum disulfide, molybdenum carbide The types of compound which find application are overwhelmingly agriculture molybdates molybdenum-oxygen compounds and molybdenum-sulfur compounds, see Table 2. However compounds of The outstanding feature of most inorganic and organic ligands, molybdenum with other elements molybdenum is its extraordinary with a particular preference for oxygen, sulfur, fluorine and chlorine donor continue to attract interest and feature chemical versatility: atoms; in the research and patent literature. ■ oxidation states from –II to VI; ■ Compounds are listed in Table 2 with ■ coordination numbers from 4 to 8; formation of bi- and polynuclear an indication of actual use (italicised) compounds containing bridging oxide ■ varied stereochemistry; or chloride ligands and/or molybdenum- or proposed use and numbers of US ■ patents since 1976. the ability to form compounds with molybdenum bonds. Basic Molybdenum Chemistry Molybdenum is an element of the second transition series in Group 6 of the Periodic Table between chromium and tungsten. Chemically molybdenum resembles tungsten much more than chromium. For example, the highest oxidation state (VI) of molybdenum and tungsten (molybdates and tungstates) is much less oxidising than chromium(VI) (chromate and dichromate). Fig. 1 Molybdenum chemicals usage in metric tonnes (1000 kg) contained Mo, United States 2002. Data from the US Geological Survey Minerals Division. 2 http://minerals.usgs.gov/minerals/pubs/commodity/molybdenum/molybmyb02.pdf Entering Molybdenum Chemistry— Making Molybdenum Fig. 2 Preparative chemistry of molybdenum. The highlighted compounds and molybdenum Compounds metal are those which find high volume applications. Compounds commonly used as ■ Calcination of an ammonium starting compounds in preparative molybdate giving a sublimed, pure Higher Oxidation molybdenum chemistry are molybdenum trioxide. molybdenum trioxide, and ammonium States ■ and sodium molybdates. Reduction with hydrogen to molybdenum metal. The commonly encountered The preparative chemistry of compounds of molybdenum in its ■ Reactions with carbon monoxide or molybdenum is summarised in Fig. 2 applications are molybdenum trioxide carbon and ammonia giving and molybdates (oxidation state VI) starting with molybdenum disulfide, the molybdenum carbide and nitride. principal ore of molybdenum. and molybdenum disulfide (oxidation state VI) (see Table 1). Molybdenum disulfide is chemically ■ Preparation of molybdenum unreactive: we enter molybdenum pentachloride and molybdenum chemistry through molybdenum hexacarbonyl. The pentachloride rapidly Molybdates and polymolybdates trioxide, prepared by roasting hydrolyses in ambient air and is too molybdenum disulfide in air. Reactions reactive to find wide application. These are compounds of of molybdenum trioxide are shown in Molybdenum hexacarbonyl has an molybdenum(VI): sodium molybdate, Fig. 2. extensive substitution chemistry. Na2MoO4; ammonium dimolybdate, (NH4)2Mo2O7, ammonium ■ Dissolution in aqueous sodium ■ Preparation of molybdenum-sulfur heptamolybdate, (NH4)6Mo7O24 .4H2O hydroxide or ammonia giving simple compounds by reaction with hydrogen and ammonium octamolybdate, molybdate salts and polymolybdates disulfide or organo-sulfur compounds. (NH4)4Mo8O26. They are readily which may be crystallised (see later). available commercially and are the starting point for the preparation of many other molybdenum compounds. Table 2 Mo compounds—Partner Element(a) Applications(b) Patents (c) Sodium molybdate crystals contain 2- the discrete tetrahedral [MoO4] ion. BC NO F The polymolybdates consist of linked polyhedra containing six- and four-, and Mo2B Mo2C Mo2N MoO3, MoF6 molybdates catal. less commonly five-coordinate catal. catal. catal. catal. molybdenum(VI). ceram. corros. pigment Molybdenum trioxide and the smoke molybdates of colourless cations are 168 817 299 3671 89 themselves colourless. Blue or green colours are due to the presence of Si P S Cl reduced impurities except for those MoSi2 MoP MoS2 MoCl5 molybdates where the cation is ceram. catal. catal. catal. glasses lub. coloured, e.g. violet cobalt(II) molybdate, CoMoO4, and green 1827 15 4381 244 nickel(II) molybdate, NiMoO4 Se Br, I (=X) In aqueous solution molybdate and MoSe2 MoBr4, MoI3 Batt. polymolybdate ions are in rapid equilibria; the species depends on the 30 pH and the concentration,see Table3. (a) Listed in Periodic Table order. (b) batt., batteries and electrode materials; catal., catalyst; ceram., The molybdate species in aqueous ceramic; corros., corrosion inhibitor; lub., lubricant; pigment, pigment; smoke, smoke suppressant. solutions of molybdenum(VI) Significant uses are italicised. (c) Figures in red are the numbers of patents in the US Patent data base, 1976 (speciation)are listed in Table 3. to present (http://www.uspto.gov/patft/index.html). 3 Table 3 Mo(VI) Species in Aqueous Solution 2_ green [MoOCl5] species is formed. With a more powerful reducing agent, -1 pH Mo concentration/ mol l Mo(VI) species e.g. zinc amalgam, reduction proceeds to hydrated molybdenum(III) species. 2- >7 all [MoO4] Typical reduction potentials (in volts) in acidic solution are for Mo(VI)/Mo(V), -3 -1 6– 5–6 >10 mol l [Mo7O24] 0.50, and for Cr(VI)/Cr(III), 1.35. The more positive is the potential,the more -3 -1 4– 3–5 >10 mol l [Mo8O26] oxidising is the couple. -3 -1 0.9 >10 mol l MoO3 precipitates Compounds of molybdenum(II) and lower oxidation states are stabilised by Mo-Mo bonds as in molybdenum(II) Which compounds crystallise from with tetrahedrally coordinated acetate, Mo2(CH3CO2)4, and solution depends on the conditions: heteroatoms (X). An example is molybdenum(II) chloride, Mo6Cl12, and concentration and pH. To prepare 12-molybdophosphoric acid by unsaturated ligands, for example, sodium molybdate, Na2MoO4.2H2O H3[PMo12O4o].28
Load more

Recommended publications
  • The Characterisation of Electrodeposited Mos2 Thin Films on a Foam-Based Electrode for Hydrogen Evolution
    catalysts Article The Characterisation of Electrodeposited MoS2 Thin Films on a Foam-Based Electrode for Hydrogen Evolution Ramunas Levinas 1,* , Natalia Tsyntsaru 1,2 and Henrikas Cesiulis 1 1 Faculty of Chemistry and Geosciences, Vilnius University, Naugarduko str. 24, 03225 Vilnius, Lithuania; [email protected] (N.T.); [email protected] (H.C.) 2 Institute of Applied Physics of ASM, 5 Academiei str., 2028 Chisinau, Moldova * Correspondence: [email protected]; Tel.: +370-64875762 Received: 21 September 2020; Accepted: 6 October 2020; Published: 14 October 2020 Abstract: Molybdenum sulphide is an emerging precious-metal-free catalyst for cathodic water splitting. As its active sites catalyse the Volmer hydrogen adsorption step, it is particularly active in acidic media. This study focused on the electrochemical deposition of MoS2 on copper foam electrodes and the characterisation of their electrocatalytic properties. In addition, the electrodeposition was modified by adding a reducing agent—sodium hypophosphite—to the electrolyte. To reveal the role of hypophosphite, X-ray photoelectron spectroscopy (XPS) analysis was carried out in addition to scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). MoS2 films, electrodeposited at various charges passed through the cell (catalyst loadings), were tested for their catalytic activity towards hydrogen evolution in 0.5 M H2SO4. Polarisation curves and Tafel slope analysis revealed that the electrodeposited MoS2 films are highly active. Namely, Tafel slopes 1 fell within the 40–50 mV dec− range. The behaviour of as-deposited films was also evaluated by electrochemical impedance spectroscopy over a wide overpotential range (0 to 0.3 V), and two clear − time constants were distinguished.
    [Show full text]
  • And Multi-Layer Mos2 Field Effect Transistor
    electronics Article Efficient and Versatile Modeling of Mono- and Multi-Layer MoS2 Field Effect Transistor Nicola Pelagalli 1,* , Emiliano Laudadio 2 , Pierluigi Stipa 2 , Davide Mencarelli 1 and Luca Pierantoni 1 1 Departement of Information Engineering, Marche Polytechnic University, 60131 Ancona, Italy; [email protected] (D.M.); [email protected] (L.P.) 2 Department of Materials, Environmental Sciences and Urban Planning, Marche Polytechnic University, 60131 Ancona, Italy; [email protected] (E.L.); [email protected] (P.S.) * Correspondence: [email protected] Received: 1 August 2020; Accepted: 24 August 2020; Published: 27 August 2020 Abstract: Two-dimensional (2D) materials with intrinsic atomic-level thicknesses are strong candidates for the development of deeply scaled field-effect transistors (FETs) and novel device architectures. In particular, transition-metal dichalcogenides (TMDCs), of which molybdenum disulfide (MoS2) is the most widely studied, are especially attractive because of their non-zero bandgap, mechanical flexibility, and optical transparency. In this contribution, we present an efficient full-wave model of MoS2-FETs that is based on (1) defining the constitutive relations of the MoS2 active channel, and (2) simulating the 3D geometry. The former is achieved by using atomistic simulations of the material crystal structure, the latter is obtained by using the solver COMSOL Multiphysics. We show examples of FET simulations and compare, when possible, the theoretical results to the experimental from the literature. The comparison highlights a very good agreement. Keywords: field-effect transistor; molybdenum disulfide; 2D materials; ferroelectric; hafnium zirconium oxide; atomistic simulations 1. Introduction Mono-layer transition metal dicalchogenides are chemical compounds in which molecules are formed by one transition metal atom (Mo, W, Pt, etc.) and two atoms belonging to group 16 of the periodic table of elements (S, O, Pt).
    [Show full text]
  • Growth of Two-Dimensional Molybdenum Disulfide Via Chemical Vapor Deposition
    Wright State University CORE Scholar Browse all Theses and Dissertations Theses and Dissertations 2019 Growth of Two-Dimensional Molybdenum Disulfide via Chemical Vapor Deposition Zachary Durnell Ganger Wright State University Follow this and additional works at: https://corescholar.libraries.wright.edu/etd_all Part of the Engineering Science and Materials Commons Repository Citation Ganger, Zachary Durnell, "Growth of Two-Dimensional Molybdenum Disulfide via Chemical aporV Deposition" (2019). Browse all Theses and Dissertations. 2174. https://corescholar.libraries.wright.edu/etd_all/2174 This Thesis is brought to you for free and open access by the Theses and Dissertations at CORE Scholar. It has been accepted for inclusion in Browse all Theses and Dissertations by an authorized administrator of CORE Scholar. For more information, please contact [email protected]. GROWTH OF TWO-DIMENSIONAL MOLYBDENUM DISULFIDE VIA CHEMICAL VAPOR DEPOSITION A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Materials Science and Engineering By ZACHARY DURNELL GANGER B.S.M.S.E. Wright State University, 2015 2019 Wright State University WRIGHT STATE UNIVERSITY GRADUATE SCHOOL March 28th, 2019 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Zachary Durnell Ganger ENTITLED Growth of Two Dimensional Molybdenum Disulfide via Chemical Vapor Deposition BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science in Materials Science and Engineering. Committee on Final Examination ______________________________ Hong Huang, Ph.D. ________________________________ Thesis Director Hong Huang, Ph.D. Joseph C. Slater, Ph.D., P.E. ________________________________ Chair, Department of Mechanical and Materials Engineering Yan Zhuang, Ph.D.
    [Show full text]
  • Functionalization of Molybdenum Disulfide Via Plasma Treatment And
    nanomaterials Article Functionalization of Molybdenum Disulfide via Plasma Treatment and 3-Mercaptopropionic Acid for Gas Sensors Won Seok Seo 1, Dae Ki Kim 1, Ji-Hoon Han 2, Kang-Bak Park 1, Su Chak Ryu 2, Nam Ki Min 1,* and Joon Hyub Kim 2,* 1 Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-ro, Sejong-si 30019, Korea; [email protected] (W.S.S.); [email protected] (D.K.K.); [email protected] (K.-B.P.) 2 Department of Nanomechatronics Engineering, Pusan University, Busan, 2 Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 46241, Korea; [email protected] (J.-H.H.); [email protected] (S.C.R.) * Correspondence: [email protected] (N.K.M.); [email protected] (J.H.K.) Received: 24 August 2020; Accepted: 15 September 2020; Published: 17 September 2020 Abstract: Monolayer and multilayer molybdenum disulfide (MoS2) materials are semiconductors with direct/indirect bandgaps of 1.2–1.8 eV and are attractive due to their changes in response to electrical, physicochemical, biological, and mechanical factors. Since the desired electrical properties of MoS2 are known, research on its electrical properties has increased, with focus on the deposition and growth of large-area MoS2 and its functionalization. While research on the large-scale production of MoS2 is actively underway, there is a lack of studies on functionalization approaches, which are essential since functional groups can help to dissolve particles or provide adequate reactivity. Strategies for producing films of functionalized MoS2 are rare, and what methods do exist are either complex or inefficient.
    [Show full text]
  • Comparisons Between Naturally-Occurring and Chemically- Produced (Synthetic) Molybdenum Disulfide Dr. Philip Mitchell, March 2012
    Comparisons between naturally-occurring and chemically- produced (synthetic) molybdenum disulfide Dr. Philip Mitchell, March 2012 Naturally-occurring molybdenum disulfide is extracted from molybdenite ore. In its lubricant-grade fine powder form, as a dark grey or black solid, it is the molybdenum disulfide supplied and distributed by chemical suppliers for use as a lubricant either dry or in suspension in an oil or grease. In its coarser powder form molybdenum disulfide is the feedstock for roasting into technical grade molybdenum trioxide. Naturally-occurring molybdenum disulfide For natural molybdenum disulfide as used as a lubricant, the particle size depends on the grade (the extent of grinding). For example the Climax Molybdenum Technical Fine has particles of ca. 6 μm (finely ground) and the Technical grade (natural) ca. 30 μm (Yakov Epshteyn and Thomas J. Risdon, Molybdenum Disulfide In Lubricant Applications – A Review, Climax Molybdenum, presented at the 12th Lubricating Grease Conference, January 2010, Goa, India). The surface area of natural molybdenum disulfide of particle size 35 µm was 1 m2 g−1 (www.specialchem4polymers.com/urw/lubricants-surface.aspx). Supported chemically-produced (synthetic) molybdenum disulfide catalysts Chemically-produced (synthetic) molybdenum disulfide as encountered in the catalyst industry is prepared by sulfiding molybdenum trioxide, i.e. heating the oxide in hydrogen sulfide or with an organic sulfur compound. Molybdenum disulfide-based catalysts are used in the hydrodesulfurisation of organic sulfur compounds in petroleum crudes. The molybdenum disulfide is supported on alumina. Cobalt or nickel is added as a catalyst promoter. The sulfided catalyst may be prepared in situ, i.e. by sulfiding a supported molybdenum trioxide precursor in the reactor or ex situ, i.e.
    [Show full text]
  • Growth and Characterization of Molybdenum Disulfide Thin Films
    Growth and Characterization of Molybdenum Disulfide Thin Films A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering by Carl M. Gross III B.S.E.E., Wright State University, 2015 2016 Wright State University Wright State University Graduate School May 25 2016 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPER- VISION BY Carl M. Gross III ENTITLED Growth and Characterization of Molybdenum Disulfide Thin Films BE ACCEPTED IN PARTIAL FULFILLMENT OF THE RE- QUIREMENTS FOR THE DEGREE OF Master of Science in Electrical Engineering. ____________________________________ Yan Zhuang, Ph.D. Thesis Director ____________________________________ Brian D. Rigling, Ph.D. Chair, Department of Electrical Engineering College of Engineering and Computer Science Committee on Final Examination ____________________________________ Yan Zhuang, Ph.D. Associate Professor of Electrical Engineering ____________________________________ Shin Mou, Ph.D. ____________________________________ Michael A. Saville, PhD, PE Assistant Professor of Electrical Engineering ____________________________________ Robert E. Fyffe, Ph.D. Vice President for Research and Dean of the Graduate School ABSTRACT Gross, Carl. M.S.E.E. Department of Electrical Engineering, Wright State University, 2016. Growth and Characterization of Molybdenum Disulfide Thin Films. Two-dimensional materials, or materials that are only one atomic layer thick, have seen much research in recent years because of their interesting electrical properties. The first of these materials, graphene, was found to have incredible electrical properties but lacked a bandgap in intrinsic films. Without a bandgap, graphene cannot create transistors that can be shut off. Molybdenum disulfide, however, is a two-dimensional semiconductor with a large bandgap. The main issue of molybdenum disulfide is that synthesized films are a much lower quality than their exfoliated counterparts.
    [Show full text]
  • Production and Properties of Molybdenum Disulfide/Graphene
    nanomaterials Article Production and Properties of Molybdenum Disulfide/Graphene Oxide Hybrid Nanostructures for Catalytic Applications Zuzanna Bojarska 1 , Marta Mazurkiewicz-Pawlicka 1 , Stanisław Gierlotka 2 and Łukasz Makowski 1,* 1 Faculty of Chemical and Process Engineering, Warsaw University of Technology, 00-645 Warsaw, Poland; [email protected] (Z.B.); [email protected] (M.M.-P.) 2 Polish Academy of Sciences, Institute of High Pressure Physics UNIPRESS, 01-424 Warsaw, Poland; [email protected] * Correspondence: [email protected] Received: 22 August 2020; Accepted: 14 September 2020; Published: 17 September 2020 Abstract: Molybdenum disulfide (MoS2) can be an excellent candidate for being combined with carbon nanomaterials to obtain new hybrid nanostructures with outstanding properties, including higher catalytic activity. The aim of the conducted research was to develop the novel production method of hybrid nanostructures formed from MoS2 and graphene oxide (GO). The nanostructures were synthesized in different weight ratios and in two types of reactors (i.e., impinging jet and semi-batch reactors). Physicochemical analysis of the obtained materials was carried out, using various analytical techniques: particle size distribution (PSD), thermogravimetric analysis (TGA), FT-IR spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Due to the potential application of materials based on MoS2 as the catalyst for hydrogen evolution reaction, linear sweep voltammetry (LSV) of the commercial MoS2, synthesized MoS2 and the obtained hybrid nanostructures was performed using a three-electrode system. The results show that the developed synthesis of hybrid MoS2/GO nanostructures in continuous reactors is a novel and facile method for obtaining products with desired properties.
    [Show full text]
  • MOLY-LIT™, Molybdenum Disulfide Based Anti-Seize Compound
    Technical Data Sheet P/N 12000 Series Page 1 of 1 ™ March 2016 June 20 TM MOLY-LIT Molybdenum Disulfide Based Anti-Seize Compound www.antiseize.com Product Description Typical Properties Moly-Lit™ is an extra heavy-duty, extreme- Property Value pressure, and low-friction Anti-Seize Compound and Specific Gravity 1.38 lubricant. It offers a high concentration of molybdenum Weight per gallon 11.5 LB disulfide, graphite, and other anti-wear solids in a high- Penetration, D217-60T, 290 - 320 performance carrier. Moly-Lit™ is designed for highly 100-3000 Strokes loaded parts in difficult installations. It features larger Oil Separation, 1% particle size fillers for maximum performance on larger 30 hr. at 158˚F parts. Use it to protect valuable parts and equipment to Flash point, 450˚F temperatures up to 2,400ºF (1,315ºC). ASTM D-92-85 (IP 36/65) Moly-Lit™ Anti-seize compound delivers maximum Black performance for highly loaded fasteners subjected to Color high shock loads. Recommended for threads, pipes, Friction Coefficient 0.085 valves, and equipment carrying ethylene, acetylene, and Torque Coefficient K Values 0.15 ± 0.02. other services where copper contamination must be "nut factor" Testing is required to avoided. determine Meets Performance Requirements of MIL-PRF-907E. the exact K values & specific performance on any Features & Benefits individual fastener using the desired Designed for Heavily Loaded threaded assemblies anti-seize compound. Works where other compounds fail Homogeneity Will not settle, harden or Protects against seizing
    [Show full text]
  • 4D7ecc4538da2dbc87dd10f
    international journal of hydrogen energy xxx (2016) 1e13 Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he Two-dimensional molybdenum disulfide and tungsten disulfide interleaved nanowalls constructed on silk cocoon-derived N-doped carbon fibers for hydrogen evolution reaction ** * QingFa Wang a, , RuoPing Yanzhang a, XiaoNa Ren a, Han Zhu b, , Ming Zhang b, MingLiang Du b a Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, 92 Weijin Road, Tianjin, 300072, PR China b Department of Materials Engineering, College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou, 310018, PR China article info abstract Article history: Finding cost-effective, active and durable catalyst materials for energy applications, such Received 14 June 2016 as electrocatalytic hydrogen production, is an intriguing challenge. Here, a facile and Received in revised form effective approach to the design and construction of two-dimensional MoS2 and WS2 23 July 2016 interleaved nanowalls with maximum exposures of active edges on silk-derived N-doped Accepted 28 July 2016 carbon fibers (SNCF) was demonstrated. The morphological evolutions of the MoS2 and Available online xxx WS2 nanocrystals on the SNCF from crescent-like nanosheets to an interleaved nanowall network can be obtained by adjusting the concentrations of the Mo and W precursors. Keywords: These robust MoS2/SNCF and WS2/SNCF electrocatalysts exhibit prominent hydrogen Silk derived N-doped carbon evolution reaction (HER) activities with onset potentials of À40 and À96 mV and Tafel À À Molybdenum sulfides slopes of 60 and 66 mV dec 1, respectively.
    [Show full text]
  • Commercialization of Cobalt Promoted Molybdenum Disulfide
    University of Texas at El Paso DigitalCommons@UTEP Open Access Theses & Dissertations 2016-01-01 Commercialization Of Cobalt Promoted Molybdenum Disulfide yH drodesulfurization Unsupported Catalyst Juan Hilario Leal University of Texas at El Paso, [email protected] Follow this and additional works at: https://digitalcommons.utep.edu/open_etd Part of the Petroleum Engineering Commons Recommended Citation Leal, Juan Hilario, "Commercialization Of Cobalt Promoted Molybdenum Disulfide yH drodesulfurization Unsupported Catalyst" (2016). Open Access Theses & Dissertations. 878. https://digitalcommons.utep.edu/open_etd/878 This is brought to you for free and open access by DigitalCommons@UTEP. It has been accepted for inclusion in Open Access Theses & Dissertations by an authorized administrator of DigitalCommons@UTEP. For more information, please contact [email protected]. COMMERCIALIZATION OF COBALT PROMOTED MOLYBDENUM DISULFIDE HYDRODESULFURIZATION UNSUPPORTED CATALYST JUAN HILARIO LEAL Doctoral Program in Materials Science and Engineering APPROVED: Russell R. Chianelli, Ph.D., Chair Devesh Misra, Ph.D. Felicia Manciu, Ph.D. Binata Joddar, Ph.D. Charles Ambler, Ph.D. Dean of the Graduate School Copyright © by Juan Hilario Leal 2016 Dedication I dedicate this to my family and especially my daughter, Caroline. The people of El Paso, including UTEP faculty and friends have made this a memorable experience. Thank you to all my friends, which I will not name, but you know who you are. I would not have made it without your support. COMMERCIALIZATION OF COBALT PROMOTED MOLYBDENUM DISULFIDE HYDRODESULFURIZATION UNSUPPORTED CATALYST by JUAN HILARIO LEAL, M.S., B.S. DISSERTATION Presented to the Faculty of the Graduate School of The University of Texas at El Paso in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Material Science and Engineering THE UNIVERSITY OF TEXAS AT EL PASO May 2016 ACKNOWLEDGEMENTS I would like to take this opportunity to thank everyone who has helped me.
    [Show full text]
  • A DFT Study of Comos and Nimos Catalysts: from Nano-Crystallite Morphology to Selective Hydrodesulfurization E
    A DFT Study of CoMoS and NiMoS Catalysts: from Nano-Crystallite Morphology to Selective Hydrodesulfurization E. Krebs, A. Daudin, P. Raybaud To cite this version: E. Krebs, A. Daudin, P. Raybaud. A DFT Study of CoMoS and NiMoS Catalysts: from Nano-Crystallite Morphology to Selective Hydrodesulfurization. Oil & Gas Science and Technol- ogy - Revue d’IFP Energies nouvelles, Institut Français du Pétrole, 2009, 64 (6), pp.707-718. 10.2516/ogst/2009004. hal-02001578 HAL Id: hal-02001578 https://hal-ifp.archives-ouvertes.fr/hal-02001578 Submitted on 31 Jan 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Oil & Gas Science and Technology – Rev. IFP, Vol. 64 (2009), No. 6, pp. 707-718 Copyright © 2009, Institut français du pétrole DOI: 10.2516/ogst/2009004 Dossier Catalysts and Adsorbents: from Molecular Insight to Industrial Optimization Catalyseurs et adsorbants : de la compréhension moléculaire à l'optimisation industrielle A DFT Study of CoMoS and NiMoS Catalysts: from Nano-Crystallite Morphology to Selective Hydrodesulfurization E. Krebs1,2, A.
    [Show full text]
  • Design and Evaluation the Anti-Wear Property of Inorganic Fullerene Tungsten Disulfide As Additive in PAO6 Oil
    crystals Article Design and Evaluation the Anti-Wear Property of Inorganic Fullerene Tungsten Disulfide as Additive in PAO6 Oil Wenting Chen 1, Kunyapat Thummavichai 2, Xiaorong Chen 1, Guangsheng Liu 1 , Xuefeng Lv 1, Linyi Zhang 1, Ding Chen 1, Santosh Kr. Tiwari 1 , Nannan Wang 1,* and Yanqiu Zhu 1,2,* 1 Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, Ministry of Education, School of Resources, Environment and Materials, Guangxi Institute Fullerene Technology (GIFT), Guangxi University, Nanning 530004, China; [email protected] (W.C.); [email protected] (X.C.); [email protected] (G.L.); [email protected] (X.L.); [email protected] (L.Z.); [email protected] (D.C.); [email protected] (S.K.T.) 2 College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK; [email protected] * Correspondence: [email protected] (N.W.); [email protected] (Y.Z.) Abstract: Inorganic fullerene-like tungsten disulfide particles have been proved to have good anti- friction and anti-wear properties as lubricating materials. As far as we know, however, when it is used as a lubricant additive, its behavior and action mechanism in the friction process are rarely studied. Herein, IF–WS2 particles were synthesized by a Chemical Vapor Deposition (CVD) method. The effect of IF–WS2 particle concentrations in the PAO6 oil on the tribological behaviors ◦ was investigated with a four-ball wear machine at both 75 and 100 C. Additionally, the analyzed morphology and composition of nanomaterials and worn surfaces were analyzed by Scanning Citation: Chen, W.; Thummavichai, electron microscopy (SEM), Transmission Electron Microscopy (TEM) and X-ray photoelectron K.; Chen, X.; Liu, G.; Lv, X.; Zhang, L.; spectroscopy (XPS).
    [Show full text]