DOCSLIB.ORG

Platinum Metals Review

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Platinum Metals Review PLATINUM METALS REVIEW A quarterly survey of research on the platinum metals and oj developments in their application in industry VOL. 40 JANUARY 1996 NO. 1 Contents Rustenburg and Johnson Matthey, an Enduring Relationship 2 Platinum Metals Complex Catalysts for Liquid-Phase Hydrogenations 8 Activity of Platinum-Containing Electrodes Enhanced 18 Second European Congress on Catalysis 19 Platinum Group Metal Fullerenes 23 Platinum Nanochannel Replica Membranes 25 Increased Catalytic Activity 25 The Development of Molecular Wires 26 Small-Particle Platinum Catalysts 35 Hydrogen Treatment of Materials 36 Alkane Oxidation by Encapsulated Ruthenium Complexes 37 Palladium Alloy Mechanical Properties 37 Abstracts 38 New Patents 46 Communications should he addressed to The Editor, Susan V. Ashton, Platinum Metals Revim Johnson Matthey Public Limited Company, Hatton Garden, London ECl N 8EE Rustenburg and Johnson Matthey, An Enduring Relationship SIXTY-FIVE YEARS OF CONTINUOUS COMMITTED DEVELOPMENT By J. Todd Bruce Marketing and Planning Director, Anglo American Platinum Corporation Limited, Johannesburg, South Africa The background and history of the connection between the world’s largest platinum producing group, the South African company Anglo American Platinum Corporation, and the United Kingdom company Johnson Matthey, is explained. The commitment of Amplats to meet the expected growth in demand for the six platinum group metals in the future and the role of Johnson Matthey in marketing these metals, and in contributing towards the development of advanced technological applications for them, will ensure that the needs of the industrial platinum users throughout the world will continue to be satisfied. Prior to 1st January, 1995, Johannesburg als and base metals produced from the mining Consolidated Investment Company Limited, operations at Rustenburg. “JCI”, one of the leading mining finance houses The fledgling South African platinum indus- in South Africa, controlled and managed three try suffered a severe blow in 1932 with the platinum group metals producing companies: depression-induced collapse of the platinum Rustenburg Platinum Holdings Limited, price on international markets. As a result, min- Lebowa Platinum Mines Limited and ing operations at Rustenburg were suspended Potgietersrust Platinums Limited. On 1st until the end of 1933 when they were recom- January, 1995, the Anglo American Corporation menced on the advice of Johnson Matthey. of South Africa, the controlling shareholder of In 1938 Rustenburg’s first major expansion JCI, restructured JCI forming three separate programme, to 20,000 tons per month, was companies: a platinum mining operation, the completed and the iirst smelter furnace and con- Anglo American Platinum Corporation Limited, verter unit were commissioned. At this point “Amplats”; a gold, coal and base metals min- the material delivered to Johnson Matthey ing operation, “JCI Ltd”, and an industrial and changed from platinum group metal concen- property investment holding company, trates to the less bulky converter matte. “Johnnic”. Amplats is controlled by the Anglo During the Second World War years, 1939 American Corporation of South Africa. to 1945, mine production remained steady at Johnson Matthey’s links to the South African around 25,000 tons per month, but as a result platinum mining industry stretch back to the of improvements in Johnson Matthey’s pro- discovery of platinum-bearing deposits in the cessing and refining technology, production of Bushveld Igneous Complex in 1924. The sub- refined platinum increased to some 40,000 sequent founding of Rustenburg Platinum Mines ounces per annum. in 1931 to exploit the Merensky Reef marked After the war an upsurge in platinum demand, the start of an enduring relationship between initially from the chemical industry and later Rustenburg, the largest platinum producer in from other industrial sectors, resulted, over the the world, and Johnson Matthey as agent, cus- next 30 years, in an ongoing series of expan- tomer and refiner of the platinum group met- sions in production at Rustenburg. Platinum Platinum Metals Rev., 1996, 40, (l), 2-7 2 Theo.1 shaft at Amandelbult Section output at Rustenburg doubled between 1947 reached with Johnson Matthey to form a jointly and 1949, in part by the acquisition in 1949 held company, Matte Smelters (Pty) Ltd, to of the operations of the Union Platinum Mining erect and operate a plant in South Africa to pro- Co. Ltd. A decision to double the output again duce saleable nickel and copper and a high grade was taken in 195 1 (at which time Rustenburg platinum group metals refinery feed Erom a por- was producing ore at a rate of about 70,000 tons tion of the matte produced by Rustenburg. The per month). At the same time agreement was balance of the Rustenburg matte continued to Potgietersrust Platinum8 - the only open cast platinum mining project in South Africa Platinum Merals Rev., 1996,40, (1) 3 be exported to Johnson Matthey in the United metals refinery, Matte Smelters and Johnson Kingdom for processing. The Matte Smelters Matthey’s smelting and refining operations at plant was commissioned during 1954/1955. Brimsdown and Royston in the U.K. The platinum requirements of the oil indus- The platinum market slumped severely in 197 1 try in the mid-1950s led to two hther expan- causing Rustenburg to cut production by almost sion programmes at Rustenburg, in 1955/56 50 per cent to some 550,000 ounces per annum. and 1956157. At this time it was also decided Fortunately, the successful development of auto- by the Board of Johnson Matthey, with the catalyst technology by Johnson Matthey and encouragement of the Directors of Rustenburg, Engelhard during the early 1970s represented to compile technical and scientific informa- the beginning of a major new application for tion on all the forms of platinum and the other platinum in 1975. In 1972, to meet this chal- platinum group metals. As part of this initiative lenge, Rustenburg decided to expand produc- the quarterly journal, Platinum Metals Review, tion beyond the previous 1 million ounces per was founded, and the first issue duly appeared annum level, by developing its Amandelbult in January 1957. Section, some 120 km north of the Rustenburg In 1958 the market experienced a sudden mining operations. Rustenburg’s production downturn attributable to a sharp reduction in capacity was further increased in 1977, when offtake by the oil industry. Production at Union the company acquired the mining operations of Section was temporarily suspended, and the Atok Platinum Mines (Pty) Ltd, situated on the output at Rustenburg was halved. However, eastern limb of the Bushveld Complex. increased industrial demand for platinum Due to the expansion in Rustenburg’s plat- emerged again during the early 1960s and inum output during the 197Os, Rustenburg and Rustenburg responded by undertaking another Johnson Matthey decided to replace the 23-year series of production expansions from about old Matte Smelters plant with a new MRR 1963 onwards, with platinum output eventu- base metals refinery which would process ally reaching 1 million ounces by 1970. These Rustenburg’s entire matte output into saleable expansions included the exploitation, under nickel, copper, cobalt and a high grade platinum tribute, which is a form of royalty agreement, group metals refinery feed. The new base met- of the mineral rights held by Brakspruit als refinery became operational in 1981/82. Platinum (Pty) Ltd, adjacent to the Rustenburg property. The assets and mineral rights of Extraction Technology Brakspruit Platinum were eventually acquired In 1980 Johnson Matthey concluded the suc- by Rustenburg in 1972. cessful testing of a pilot platinum group met- In 1969 a platinum group metals refinery, als extraction plant based on Johnson Matthey’s financed 80 per cent by Johnson Matthey and proprietary new solvent extraction, “Solvex”, 20 per cent by Rustenburg, was commissioned technology. The success of the pilot plant at Wadeville in South Africa to treat a portion prompted Johnson Matthey and Rustenburg to of Rustenburg’s platinum group metal output build a pre-production scale Solvex plant at from the Matte Smelters plant. The balance Royston. Construction began in 1981 and the of the Rustenburg material continued to be plant was commissioned in 1983. refined by Johnson Matthey at Royston in the In 1984 it was agreed by Johnson Matthey and U.K. In 1972 Rustenburg and Johnson Matthey Rustenburg that Rustenburg should take over formed a jointly held company, Matthey sole responsibility for the crucial stages of pro- Rustenburg Refiners (Pty) Ltd, “MRR, to cessing and refining. Accordingly, Rustenburg acquire and operate the platinum group metals purchased the Wadeville platinum group met- processing facilities owned and operated by als refinery and the new base metals refinery Johnson Matthey and Rustenburg. Accordingly, from MRR. Rustenburg contracted MRR to MRR acquired the Wadeville platinum group manage the Wadeville refinery and MRR Platinum Metals Rev., 1996, 40, (1) 4 Tapping matte from the furnace at the Waterval smelter complex, Rustenburg Section continued to own and operate the platinum Rustenburg with the necessary increased capac- group metals refinery in Royston. Rustenburg ity to refine the additional platinum group met- decided in 1986 to erect a new platinum met- als sourced from two additional expansion pro- als refinery in South Africa at Rustenburg jects begun in the late 1980s. These were the Section using Johnson Matthey’s Solvex tech- Amandelbult expansion project and the devel- nology. In 1987 Rustenburg acquired a con- opment of Potgietersrust Platinums Limited, trolling share in MRR and contracted MRR the only open-cast platinum mining venture in to manage the new refinery upon completion. South Mica. The new platinum group metals In 1988 Johnson Matthey purchased the refinery was commissioned in May 1989 and Royston platinum group metals refinery from the refining of Rustenburg’s platinum group MRR. The new platinum group metals refin- metals at Wadeville and Royston ceased during ery, apart from employing the state-of-the-art the latter half of that year.
Load more

Recommended publications
  • Α,Ω-Biphenylpolyynes)
    1 ONE-POT SYNTHESIS AND CHARACTERIZATION OF POLYYNES END-CAPPED BY BIPHENYL GROUPS (α,ω-BIPHENYLPOLYYNES) Franco Cataldo1(*), Ornella Ursini2, Alberto Milani3 , Carlo S. Casari3 1Actinium Chemical Research Institute, Via Casilina 1626 A, Rome, Italy 2CNR - Istituto di Metodologie Chimiche, Montelibretti, Roma 3 Department of Energy, Politecnico di Milano via Ponzio 34/3, I-20133 Milano, Italy Abstract Stable polyyne chains terminated with biphenyl end groups (α,ω-biphenylpolyynes) were synthesized in a single step with an easy procedure by using the Cadiot-Chodkiewicz reaction conditions. The α,ω-biphenylpolyynes were separated through HPLC analysis and identified by means of their electronic absorption spectra. The α,ω-biphenylpolyynes were studied by FT-IR and Raman spectroscopy and the spectral interpretation was supported with DFT calculations. A peculiar stability of α,ω-biphenylpolyynes towards ozone was also observed. 1. Introduction The sensational report about the production of a long polyyne chain of 6000 carbon atoms enclosed in a double wall carbon nanotube (DWCNT) [1] has re-awakened the enthusiasm about carbyne, the fabulous carbon allotrope made by an infinitely long sequence of carbon atoms with sp hybridization (with either alternated single and triple bonds or cumulated double bonds). Earlier attempts to the synthesis of carbyne are reviewed for example in the book of Heimann at al. [2]. *Corresponding author. Tel: 0039-06-94368230. E-mail: [email protected] The chemical approach toward the synthesis of this long acetylenic structure for example through the Glaser coupling reaction invariably led to a crosslinked carbonaceous solid [3,4] whose solid state 13C-NMR analysis and Raman spectroscopy revealed indeed the presence of sp hybridized carbon 2 atoms but mixed with sp2 and sp3 hybridized carbon atoms due to undesired crosslinking reactions [5,6].
    [Show full text]
  • Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis Of
    The Astrophysical Journal, 889:3 (26pp), 2020 January 20 https://doi.org/10.3847/1538-4357/ab616c © 2020. The American Astronomical Society. All rights reserved. Implications for Extraterrestrial Hydrocarbon Chemistry: Analysis of Acetylene (C2H2) and D2-acetylene (C2D2) Ices Exposed to Ionizing Radiation via Ultraviolet–Visible Spectroscopy, Infrared Spectroscopy, and Reflectron Time-of-flight Mass Spectrometry Matthew J. Abplanalp1,2 and Ralf I. Kaiser1,2 1 W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA 2 Department of Chemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA Received 2019 October 4; revised 2019 December 7; accepted 2019 December 10; published 2020 January 20 Abstract The processing of the simple hydrocarbon ice, acetylene (C2H2/C2D2), via energetic electrons, thus simulating the processes in the track of galactic cosmic-ray particles penetrating solid matter, was carried out in an ultrahigh vacuum surface apparatus. The chemical evolution of the ices was monitored online and in situ utilizing Fourier transform infrared spectroscopy (FTIR) and ultraviolet–visible spectroscopy and, during temperature programmed desorption, via a quadrupole mass spectrometer with an electron impact ionization source (EI-QMS) and a reflectron time-of-flight mass spectrometer utilizing single-photon photoionization (SPI-ReTOF-MS) along with resonance-enhanced multiphoton photoionization (REMPI-ReTOF-MS). The confirmation of previous in situ studies of ethylene ice irradiation
    [Show full text]
  • A Post-Buckminsterfullerene View of Carbon Chemistry
    A POST-BUCKMINSTERFULLERENE VIEW OF CARBON CHEMISTRY Harold Kroto School of Chemistry and Molecular Sciences, University of Sussex, Brighton, BNI 9QJ UK Keywords: Cs0, Fullerenes, carbon particles INTRODUCTION The discovery of c60 Buckminsterfullerene, Fig 1, has its origins in a research programme involving synthetic chemistry, microwave spectroscopy and radioastronomyl. In 1915, at Sussex (with David Walton), the long chain polyyne H-CeC-CsC-CsN was synthesised and studied by microwave spectroscopy. Subsequently, with Takeshi Oka and NRC(0ttawa) astronomers, the molecule was discovered in space, Fig 2, by radioastronomy using the laboratory microwave frequencies. This discovery led on to the detection of the even longer carbon chain molecules HCTN, HCgN and HCl.lN in the space between the stars2. Further work aimed at understanding the formation of the chains in space focussed attention on the possibility that they are produced at the same time as carbon dust in red giant stars1,*. During experiments at Rice University in 1985 (with James Heath, Sean O'Brien, Robert Curl and Richard Smalley), designed to simulate the conditions in these stars and explore their capacity for carbon chain formation, the exciting discovery that C60 was remarkably stable was made3. It was found that under conditions where almost all the atoms in a carbon plasma had nucleated to form microparticles the molecule c60 remained behind - together with some CTO. This result was, as is now well 'known, rationalised on the basis of the closed cage structure shown in Fig 1. It was proposed that the geodesic and aromatic factors inherent in such a structure could account for the stability of the molecule.
    [Show full text]
  • Pdf 372.94 Kb
    The Development of Molecular Wires PART 11: ROLE OF RUTHENIUM AND OSMIUM POLYPYRIDINE COMPLEXES FOR FAST VECTORIAL ELECTRON TRANSFER By V. Grosshenny, A. Harriman, M. Hissler and R. Ziessel Ecole Europkenne de Hautes Etudes des Industries Chimique de Strasbourg, Universitk Louis Pasteur, Laboratoire de Chimie d’Electronique et de Photonique Molkculaires, Strasbourg, France The concludingpart of thispaper on the use of ruthenium(ZI) and osmium(II) polypyridyl complexes, as molecular sized terminal subunits that are linked together bypolyyne bridges functioning as molecular girders to retain the stereo- chemical rigidity, deals with the process of electron transfer between the subunits and considers the benefits conferred by the use of polyyne bridges. The ruthe- nium and osmium complexes have properties which aid the selective promo- tion of an electron from the metal to the bridging ligand, together with amenable absorption and emission spectral pro+, and facile oxidation-reduction processes. This makes them promising candidates for vectorial electron transfer. Future work to extend the lengths of the linkages, to ensure unidirectional and long- range electron tunnelling, and to anchor the wires to supports is discussed. These are the necessary requirements for the development of molecular wiring made from these materials forfuture use with molecular-scale electronic devices. The first part of this paper introduced the sub- metal centres, must occur between more widely- ject of molecular wires and considered the struc- spaced reactants and it displays a more signifi- ture and chemistry of the complexes that can cant attenuation factor. be used for them, and other materials currently Interestingly, the insertion of a platinum(I1) believed to be the best for this purpose (13).
    [Show full text]
  • Chemistry and Applications of Metal-Organic Materials A
    CHEMISTRY AND APPLICATIONS OF METAL-ORGANIC MATERIALS A Dissertation by DAN ZHAO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2010 Major Subject: Chemistry Chemistry and Applications of Metal-Organic Materials Copyright 2010 Dan Zhao CHEMISTRY AND APPLICATIONS OF METAL-ORGANIC MATERIALS A Dissertation by DAN ZHAO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Hong-Cai Zhou Committee Members, Abraham Clearfield François P. Gabbaï Hung-Jue Sue Head of Department, David H. Russell December 2010 Major Subject: Chemistry iii ABSTRACT Chemistry and Applications of Metal-Organic Materials. (December 2010) Dan Zhao, B.A., Zhejiang University; M.S., Zhejiang University Chair of Advisory Committee: Dr. Hong-Cai Zhou Developing the synthetic control required for the intentional 3-D arrangement of atoms remains a holy grail in crystal engineering and materials chemistry. The explosive development of metal-organic materials in recent decades has shed light on the above problem. Their properties can be tuned by varying the organic and/or inorganic building units. In addition, their crystallinity makes it possible to determine their structures via the X-ray diffraction method. This dissertation will focus on the chemistry and applications of two kinds of metal-organic materials, namely, metal-organic frameworks (MOFs) and metal-organic polyhedra (MOP). MOFs are coordination polymers. Their permanent porosity makes them a good “gas sponge”. In the first section, an isoreticular series of MOFs with dendritic hexa- carboxylate ligands has been synthesized and characterized structurally.
    [Show full text]
  • Computational Chemistry
    518 CHIMIA 2012, 66, No. 7/8 Computational Chemistry doi:10.2533/chimia.2012.518 Chimia 66 (2012) 518–531 © Schweizerische Chemische Gesellschaft ComputationalChemistry ComputationalChemistry Computational Chemistry,Talk 155 Computational Chemistry,Talk 156 ExploringPhotoinduced Intermolecular Electrontransferwith Local Control Theory in Trajectory-based Nonadiabatic Dynamics Molecular Dynamics Simulations B. F. E. Curchod1,T.J.Penfold1,2,3,U.Rothlisberger1,and I. Tavernelli1 A. Gamiz-Hernandez1,E.Vauthey2,M.Meuwly1 1Laboratory of Computational Chemistry and Biochemistry, Ecole Poly- technique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland 1UniversityofBasel/DepartmentofChemistry, Klingelbergstr. 80, CH-4055 2Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Fédérale de Basel, Switzerland Lausanne, CH-1015 Lausanne, Switzerland 2UniversityofGeneva/DepartmentofPhysicalChemistry, 30 quaiErnest- 3SwissFEL, Paul Scherrer Inst., CH-5232 Villigen, Switzerland. Ansermet, CH-1211 Geneva 4, Switzerland In the last years, linear-response time-dependent density functional theory (LR-TDDFT) has become widely used for the calculation of vertical elec- Understandingthe dynamics of photoinduced chemical processes involving tronic excitation energies of medium to large size molecular systems in gas electron transfer(ET)isacrucialstep for the designofnew technologies and condensed phases. In addition, excited state LR-TDDFT forces and such as efficient solar energy conversion devices. Photoinduced ET pro- nonadiabatic couplings have also
    [Show full text]
  • Exciton Radiative Lifetime in a Monoatomic Carbon Chain
    Exciton radiative lifetime in a monoatomic carbon chain Stella Kutrovskaya,1,2,3 Sevak Demirchyan,1,2 Anton Osipov,3,4 Stepan Baryshev, 5 Anton Zasedatelev,5,6 Pavlos Lagoudakis,5,6 and Alexey Kavokin1,2,6,7,8 1 School of Science, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China 2 Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China 3 Department of Physics and Applied Mathematics, Stoletov Vladimir State University, 600000 Gorkii street, Vladimir, Russia 4 ILIT RAS | Branch of FSRC \Crystallography and Photonics" RAS,1 Svyatoozerskaya, Shatura, 140700, Moscow region, Russia 5 Skolkovo Institute of Science and Technology, 30 Bolshoy Boulevard, bld. 1, 121205 Moscow, Russia 6 Physics and Astronomy, University of Southampton, Highfield, Southampton, SO171BJ, United Kingdom 7 Russian Quantum Center, Skolkovo IC, Bolshoy Bulvar 30, bld. 1, Moscow 121205, Russia 8 NTI Center for Quantum Communications, National University of Science and Technology MISiS, Moscow 119049, Russia Linear carbon-based materials such as polyyne and cumulene oligomers provide a versatile platform for nano- physics and engineering. Direct gap quasi-1D polyyne structures are promising for the observation of strong and unusual excitonic effects arising due to the two-dimensional quantum confinement. Recently, we reported on the observation of sharp exciton peaks in low temperature photoluminescence spectra of polyyne chains [1]. Here, we analyse the time-resolved optical response of this system. We extend the non-local dielectric response theory to predict the exciton radiative lifetime dependence on the bandgap value and on the length of the chain.
    [Show full text]
  • Gaining Knowledge of Single Carbon Chains
    Gaining knowledge of single carbon chains J.P. Boersma, [email protected] With thanks to: Mikhail Akhukov, Annalisa Fasolino Theory of condensed matter, Radboud University Nijmegen June 29, 2011 Contents 1 Abstract 2 2 Introduction 3 3 Computational Methods 4 4 Results & Discussion 5 4.1 Periodic & isolated carbon chains . 5 4.2 Periodic carbon chain with ribbon . 9 4.3 Isolated carbon chains with hydrogens . 10 5 Conclusion 15 6 Future Plans 16 References 17 1 1 Abstract There is not much knowledge of the behavior of nanosized parts of graphene. One interesting question is whether carbon ribbons or chains could be used to connect graphene parts and serve as a current conductor. Therefore we did calculations on 'single' graphene ribbons (benzene stripes) at first, which point out that the stripes aren't stable. Two periodic chains are formed. Instead of periodic chains we did mostly calculations on finite carbon chains, which are more relevant for our question. Previous research has shown that these chains are stable [1]. We studied the convergence of energies, distances and distance alternation in chains with periodic and free boundary conditions and in carbon chains with varying termination. These terminations were one, two or three hydrogens or a graphene ribbon. The bond lenghts, binding energies and charge densities were determined for these chains. From these properties we can conclude that adding termination to isolated carbon chains causes more alternation in bond lengths. There is a difference in formation energies and bond lengths between an even and odd number of carbon atoms in a chain and thus a difference in stability with the chain with an even number of carbon atoms being the stablest chain.
    [Show full text]
  • Linear Carbon Chains: Ultimate 1D Crystals
    Linear carbon chains: ultimate 1D crystals Alexey Kavokin International Center for Polaritonics This work has been done by A. Kucherik M. Portnoi, R. V. Samyshkin, Stella Kutrovskaya Hartmann A. Osipov, S. Arakelyan A and A Povolotsky M. Scarselli M. De Crescenzi P. Lagoudakis, A. Zasedatelev, S. Baryshev International Center for Polaritonics Growth and Fabrication Unit Quantum Nanoscience Lab Theory group Quantum Materials Lab The outline • Carbyne: an elusive allotrope of carbon • Laser ablation and stabilisation of C-chains • Deposition on a substrate • TEM and X-ray analysis, Raman spectra • Low-temperature photoluminescence reveals strong exciton features! • Conclusions Carbon hybridization and resulting nano-objects 5 Carbyne: the ultimate one-dimensional crystal Cummulene (=C=C=)n 2010 Polyyne 1996 (-C≡C-)n An elusive allotrope of carbon The most robust of all known crystals! Carbyne: high expectations CUMULENE AND POLYYNE ARE SEMICONDUCTORS CUMULENE POLYYNE The band gap predicted for infinite chains: cumulene (=C=C=)n - 0.41eV (under high pressure) polyyne (-C≡C-)n - 1 eV (atmospheric pressure) ACS-NANO, 7(11), 10075 (2013); Synthetic Metals, 17, 557(1987); Nat. Commun. 6, 6636 (2015) 8 The problem: Freestanding linear chains of over 6 atoms are theoretically unstable to bending and folding They need to be stabilized! Our method of the carbyne synthesis -CΞC- Graphene decomposition into the polyyne chains LASER HEATING OF CARBON TARGET 2 1 c B a a r n b d y y n e 1. Jagdish Narayan and Anagh BhaumikJournal of Applied Physics 118, 215303 (2015); 2. M. C. Downer et al, International Journal of Thermophysics, Vol. 14, No.
    [Show full text]
  • Jupiter's Ammonia Clouds—Localized Or Ubiquitous?
    ARTICLE IN PRESS Planetary and Space Science 53 (2005) 498–507 www.elsevier.com/locate/pss Jupiter’s ammonia clouds—localized or ubiquitous? S.K. Atreyaa,Ã, A.S. Wonga, K.H. Bainesb, M.H. Wongc, T.C. Owend aDepartment of Atmospheric, Oceanic, and Space Sciences, The University of Michigan, Ann Arbor, MI 48109-2143, USA bJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA cAstronomy Department, University of California, Berkeley, CA 94720, USA dInstitute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA Received 10 November 2003; received in revised form 9 April 2004; accepted 13 April 2004 Available online 8 February 2005 Abstract From an analysis of the Galileo Near Infrared Imaging Spectrometer (NIMS) data, Baines et al. (Icarus 159 (2002) 74) have reported that spectrally identifiable ammonia clouds (SIACs) cover less than 1% of Jupiter. Localized ammonia clouds have been identified also in the Cassini Composite Infrared Spectrometer (CIRS) observations (Planet. Space Sci. 52 (2004a) 385). Yet, ground- based, satellite and spacecraft observations show that clouds exist everywhere on Jupiter. Thermochemical models also predict that Jupiter must be covered with clouds, with the top layer made up of ammonia ice. For a solar composition atmosphere, models predict the base of the ammonia clouds to be at 720 mb, at 1000 mb if N/H were 4 solar, and at 0.5 bar for depleted ammonia of 2  10À solar (Planet. Space Sci. 47 (1999) 1243). Thus, the above NIMS and CIRS findings are seemingly at odds with other observations and cloud physics models. We suggest that the clouds of ammonia ice are ubiquitous on Jupiter, but that spectral identification of all but the freshest of the ammonia clouds and high altitude ammonia haze is inhibited by a combination of (i) dusting, starting with hydrocarbon haze particles falling from Jupiter’s stratosphere and combining with an even much larger source—the hydrazine haze; (ii) cloud properties, including ammonia aerosol particle size effects.
    [Show full text]
  • Carbon Allotrope, Cyclo[18]Carbon
    This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. Published in Science First release: 15 Aug 2019, DOI: 10.1126/science.aay1914 An sp-hybridized molecular carbon allotrope, cyclo[18]carbon Katharina Kaiser,1† Lorel M. Scriven,2† Fabian Schulz,1 Przemyslaw Gawel,2* Leo Gross,1* Harry L. Anderson2* 1 IBM Research–Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland 2 Department of Chemistry, Oxford University, Chemistry Research Laboratory, Oxford, OX1 3TA, United Kingdom † These authors contributed equally. *Corresponding authors. Email: [email protected]; [email protected]; [email protected] Abstract: Carbon allotropes built from rings of two-coordinate atoms, known as cyclo[n]carbons, have fascinated chemists for many years, but until now they could not be isolated or structurally characterized, due to their high reactivity. We generated cyclo[18]carbon (C18) using atom manipulation on bilayer NaCl on Cu(111) at 5 Kelvin by eliminating carbon monoxide from a cyclocarbon oxide molecule C24O6. Characterization of cyclo[18]carbon by high-resolution atomic force microscopy revealed a polyynic structure with defined positions of alternating triple and single bonds. The high reactivity of cyclocarbon and cyclocarbon oxides allows covalent coupling between molecules to be induced by atom manipulation, opening an avenue for the synthesis of other carbon allotropes and carbon-rich materials from the coalescence of cyclocarbon molecules. 1 The discovery of fullerenes (1), carbon nanotubes (2), and graphene (3), all of which consist exclusively of 3-coordinate carbon atoms, has sparked a new field of synthetic carbon allotropes (4, 5).
    [Show full text]
  • Data-Driven UPLC-Orbitrap MS Analysis in Astrochemistry
    life Article Data-Driven UPLC-Orbitrap MS Analysis in Astrochemistry Alexander Ruf 1,∗ , Pauline Poinot 2, Claude Geffroy 2 , Louis Le Sergeant d’Hendecourt 1 and Gregoire Danger 1,* 1 Laboratoire de Physique des Interactions Ioniques et Moléculaires (PIIM), Université Aix-Marseille, Saint Jérôme—AVE Escadrille Normandie Niemen, 13013 Marseille, France; [email protected] (A.R.); [email protected] (L.L.S.d.) 2 Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), Université de Poitiers, UMR CNRS 7285, 86073 Poitiers, France; [email protected] (P.P.); [email protected] (C.G.) * Correspondence: [email protected] (A.R.); [email protected] (G.D.); Tel.: +33-491288285 (G.D.) Received: 30 March 2019; Accepted: 23 April 2019; Published: 2 May 2019 Abstract: Meteorites have been found to be rich and highly diverse in organic compounds. Next to previous direct infusion high resolution mass spectrometry experiments (DI-HR-MS), we present here data-driven strategies to evaluate UPLC-Orbitrap MS analyses. This allows a comprehensive mining of structural isomers extending the level of information on the molecular diversity in astrochemical materials. As a proof-of-concept study, Murchison and Allende meteorites were analyzed. Both, global organic fingerprint and specific isomer analyses are discussed. Up to 31 different isomers per molecular composition are present in Murchison suggesting the presence of ≈440,000 different compounds detected therein. By means of this time-resolving high resolution mass spectrometric method, we go one step further toward the characterization of chemical structures within complex extraterrestrial mixtures, enabling a better understanding of organic chemical evolution, from interstellar ices toward small bodies in the Solar System.
    [Show full text]