DOCSLIB.ORG

Energy Barriers in the Dimerization Reactions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Energy Barriers in the Dimerization Reactions J. Phys. Chem. 1987, 91, 1857-1864 1857 Binary Association Complexes of LiH, BeH,, and BH,. Relative Isomer Stabilities and Barrier Heights for Their Interconversion: Energy Barriers in the Dimerization Reactions D. J. DeFrees,*lPKrishnan Raghavachari,*lbH. B. Schlegel,*'c J. A. Pople,*ld and P. v. R. Schleyer*" Department of Chemistry, Carnegie- Mellon University, Pittsburgh, Pennsylvania 1521 3; Molecular Research Institute, Palo Alto, California 94304; AT& T Bell Laboratories, Murray Hill, New Jersey 07974; Department of Chemistry, Wayne State University, Detroit, Michigan 48202; and Institut fur Organische Chemie, Universitat Erlangen- Niirnberg, 0-8520 Erlangen. Federal Republic of Germany (Received: November 17, 1986) Ab initio molecular orbital theory has been used to study the six compounds LizHz,LiBeH,, LiBH4, Be2H4,BeBH,, and B2H6. Geometry optimizations and vibrational analysis at the HF/6-31G* level indicate Li- -(H),--Li (DZh),Li- -(H),- -BeH (C2"),Li--(H),--BH (C3u),HBe--(H),--BeH (&), HBe--(H)3--BH (C3J, and H2B--(H),--BH2(&h) to be the most stable forms. Inclusion of electron correlation corrections at the MP4/6-3 IG** level does not alter these conclusions. Other isomers were also examined in detail, and it was found that the potential energy surfaces for the species are generally flat. Activation energies for isomer interconversion and hydrogen scrambling reactions are generally less than 10 kcal mol-'. Examination of the HF/3-21G potential surfaces indicates that there is no activation energy for the dimerization of LiH or BeH2. The same is true for the dimerization of BH3 at the correlated MP2/6-31G* level, although a small barrier is found on the HF/6-31G* surface. Enthalpies of complexation at 298 K from separate LiH, BeH,, and BH3 fragments, computed by using the HF/6-3 lG* harmonic frequencies and the MP4/6-3 lG** electronic energies are as follows: Li2H2,-45.9; LiBeH,, -43.6; LiBH4, -60.1; Be2H4,-30.5; BeBH,, -45.7; B2H6,-36.0 kcal mol-'. Introduction TABLE I: Distances (A) between Non-Hvdroeen Atoms The electron-deficient hydrides of lithium (LiH), beryllium molecule point group STO-3G 3-21G 6-31G' (BeH,), and boron (BH,) interact to form six binary association LiH- -LiH C,, 3.331 3.445 3.436 complexes which can contain a number of bridging hydrogen Li- -(H)2--Li D2h 2.222 2.364 2.343 atoms2*, Diborane, the experimentally well-established BH3 LiH- -BeH, C2" 3.122 3.123 3.104 dimer, has two such hydrogen^.^ LiH,2*3LiBeH3,4 and LiBH42 Li- -(H),- -BeH C2" 2.157 2.284 2.243 are known as crystalline solids; the atomization energy of the Li- -(H)3--Be C3" 1.842 1.977 1.940 lithium hydride dimer, (LiH)2,has been determined experimen- Li- -(H)2--BH, c2, 2.083 2.193 2.154 tally., Solid BeH2 is throught to be a polymer with two bridging Li- -(H)3--BH C3" 1.877 2.013 1.968 hydrogens between each pair of beryllium atoms.2*6 HBeH- -BeH2 c2, 3.977 3.174 3.777 ln an earlier ab initio molecular orbital.study,2 the relative HBe--(H),--BeH D2* 1.991 2.050 2.018 HBe- -(H),- -Be c3 " 1.738 1.803 1.774 energies of structures with various numbers of bridging hydrogens HBeH- -BH3 c, " 3.821 3.206 3.591 were considered, and it was concluded that the most stable forms HBe--(H)2-BH2 C2" 1.876 1.891 1.870 were Li- -(H)2--Li (&), Li- -(H)2--BeH (C2"),Li- -(H)3--BH HBe--(H),--BH C3" 1.686 1.732 1.700 (e3"),HBe- -(H),--BeH (D2h),HBe- -(H),--BH (C3J, and H,B--(H),--BH, D2h 1.805 1.785 1.778 H2B--(H)2- -BH2 ( D2h,with bridging and terminal hydrogens in perpendicular planes). Some of these complexes can be considered on non-hydrogen atoms). The results left a number of unanswered to be ionic. For example, lithium borohydride can be viewed as questions: a Li+ cation attached to the face of a BH4- tetrahedron, Li-- 1. Are the results modified if a higher level basis is used for (H),- -BH; structures with edge (Li- -(H)2--BH2) or corner geometry optimization? (Li- -H- -BH3) attachments are less stable. 2. Does inclusion of polarization functions on hydrogen (p The previous study was carried out entirely at the Hartree-Fock functions) change the relative energies of structures with different (HF) leveL2 Geometries were optimized with the minimal numbers of bridging atoms? STO-3G7 basis set, and single-point computations were performed 3. Do the stationary points found on the potential surface all using the 6-3 1 G* basis8 (split-valence with polarization functions correspond to local minima (separate isomers) or are some of them saddle points (transition structures connecting distinct isomers or connecting equivalent isomers) leading to scrambling of the (1) (a) Carnegie-Mellon University and Molecular Research Institute. bridging and terminal hydrogens? Current address: Molecular Research Institute. (b) Carnegie-Mellon University and AT&T Bell Laboratories. Current address: AT&T Bell 4. Are the relative isomer energies and binding energies (for Laboratories. (c) Carnegie-Mellon University and Wayne State University. dissociation to separate LiH, BeH2, and BH, fragments) altered Current address: Wayne State University. (d) Carnegie-Mellon University. significantly if electron correlation is included in the theoretical (e) Universitat Erlangen-Nilrnberg. model? (2) Dill, J. D.; Schleyer, P. v. R.; Binkley, J. S.; Pople, J. A. J. Am. Chem. SOC.1977, 99, 6159 and references cited therein. 5. What is the nature of the association reactions; are there (3) (a) Wiberg, E.; Amberger, E. Hydrides of the Elements of Main activation barriers? Groups I-IK Elsevier: Amsterdam, 1971. (b) Wade, K. Electron DeJicient Since only partial answers to some of these questions can be Compounds; Nelson: 197 1. found in the literature, much of which was cited in our previous (4) Ashby, E. C.; Prasad, H. S. Inorg. Chem. 1975, 14, 2869. (5) Ihle, H. R.; Wu, C. H. Adu. Mass Spectrom. 1978, 7A, 636. paper,* or in recent studies (cited below), a comprehensive (6) Marynick, D. S. J. Am. Chem. Soc. 1981, 103, 1328 and references reexamination of these six compounds at a uniform level oftheory cited therein. (7) Hehre, W. J.; Stewart, R. F.; Pople, J. A. J. Chem. Phys. 1969, 51, 2657. (8) Hariharan, P. C.; Pople, J. A. Theor. Chim. Acta 1973, 28, 213. 0022-3654/87/2091-1857$01.50/0 0 1987 American Chemical Society 1858 The Journal of Physical Chemistry, Vol. 91, No. 7, I987 DeFrees et al. TABLE 11: Optimized Total Energies (hartrees) and Number of Imaginary Frequencies“ molecule point group STO-3G 3-21G 6-31G* LiH -7.863 38 (0) -7.92984 (0) -7.98087 (0) BeH, -15.561 35 (oj -15.673 78 (oj -15.76593 (oj BH3 -26.070 70 (0) -26.237 30 (0) -26.39001 (0) LiH- -LiH -15.765 10 (2) -15.902 19 (0) -16.00331 (0) Li- -(H)2--Li -15.79681 (0) -15.933 25 (0) -16.035 59 (0) LiH- -BeH2 -23.44246 (2) -23.634 38 (2) -23.777 67 (2) Li- -(H)2--BeH -23.481 86 (0) -23.66447 (0) -23.81 100 (0) Li- -(H)3--Be -23.458 04 (0) -23.641 45 (0) -23.788 85 (0) Li- -(H)2--BH2 -33.99207 (1) -34.23807 (1) -34.441 92 (1) Li- -(H)3--BH -34.00247 (0) -34.243 84 (0) -34.449 98 (0) HBeH- -BeH2 -31.12357 (0) -31.34944 (1) -31.53314 (1) HBe- -(H)2--BeH -31.15400 (0) -31.378 05 (0) -31.570 19 (0) HBe- -(H)3--Be -31.10896 (0) -31.334 10 (0) -31.52786 (0) HBeH- -BH3 -41.63303 (2) -41.91566 (0) -42.15791 (2) HBe- -(H)2--BH2 -41.667 59 (0) -41.949 45 (0) -42.20074 (0) HBe--(H)3--BH -41.669 87 (0) -41.948 31 (0) -42.205 28 (0) H2B- -(H)2--BH2 -52.166 10 (0) -52.497 81 (0) -52.81240 (0) a In parentheses following the total energy. is appropriate. The objective of this paper is to examine these TABLE III: Harmonic Vibrational Frequencies (cm-’) and molecules by using newer theoretical methods in an attempt to Zero-Point Vibrational Ehergies (kcal mol-’) Evaluated at the answer the questions posed above. HF/6-31G* Level Theoretical Methods and Results point molecule group harmonic frequencies ZPE The most favorable HF/STO-3G structures, reported previ- LiH C,, 1416(a) 2.0 ously,2 were optimized by gradient minimizationg within the in- BeH2 D..h 761(~,),2107(~,), 2323(~,) 8.5 dicated symmetry constraints using the split-valence 3-21G basislo BH3 Djh 1225(a?), 1305(e’), 2693(a,’), 17.4 and the polarization 6-31G* basis set.8 Table I gives the distances 28 13(e’) between non-hydrogen atoms; full structures are published sep- Li- -(H),- -Li D2h 516(a,), 609(b3,), 851(b3,), 1.4 arately.” Addition of p polarization functions to the basis set 952(b1,), 1056(b2d, 1164(a,) used for geometry optimization (HF/6-31G** geometries) does Li- -(H)2--BeH C2, 346(bl), 589(al), 602(b2), 899(b,), 14.4 not significantly alter the result. For exam le, the HF/6-31G* 1137(b2), 1259(a,), 1517(b2), eometry for diborane is r(B-B) = 1.778 , r(B-Hb) = 1.316 1663(al), 2085(a1) w Li- -(H)3--BH C,, 491(e), 683(a,), 1225(e), 1338(al), 25.3 r(B-H) = 1.185 and L(H-B-H) = 122.1’ (Hb indicates 1, A, 1365(e), 2240(e), 2323(a,), the bridging hydrogen); this is virtually identical with the HF/ 6-31G** geometry of r(B-B) = 1.778 A, r(B-Hb) = 1.317 A, r(B-H) = 1.185 A, and L(H-B-H) = 122.0’.
Load more

Recommended publications
  • Lithium Hydride Powered PEM Fuel Cells for Long-Duration Small Mobile Robotic Missions
    Lithium Hydride Powered PEM Fuel Cells for Long-Duration Small Mobile Robotic Missions Jekanthan Thangavelautham, Daniel Strawser, Mei Yi Cheung Steven Dubowsky Abstract— This paper reports on a study to develop power supplies for small mobile robots performing long duration missions. It investigates the use of fuel cells to achieve this objective, and in particular Proton Exchange Membrane (PEM) fuel cells. It is shown through a representative case study that, in theory, fuel cell based power supplies will provide much longer range than the best current rechargeable battery technology. It also briefly discusses an important limitation that prevents fuel cells from achieving their ideal performance, namely a practical method to store their fuel (hydrogen) in a form that is compatible with small mobile field robots. A very efficient Fig. 1. Example of small robots (Left) A ball shaped hopping robot concept fuel storage concept based on water activated lithium hydride for exploration of extreme terrains and caves developed for NASA. (Right) (LiH) is proposed that releases hydrogen on demand. This iRobot 110 Firstlook used for observation, security and search and rescue. concept is very attractive because water vapor from the air is passively extracted or waste water from the fuel cell is recycled and transferred to the lithium hydride where the hydrogen is the near future. Hence, new means for powering field robots “stripped” from water and is returned to the fuel cell to form more water. This results in higher hydrogen storage efficiencies need to be considered. than conventional storage methods. Experimental results are This paper explores the use of fuel cells, and in particular presented that demonstrate the effectiveness of the approach.
    [Show full text]
  • Boron- and Nitrogen-Based Chemical Hydrogen Storage Materials
    international journal of hydrogen energy 34 (2009) 2303–2311 Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he Review Boron- and nitrogen-based chemical hydrogen storage materials Tetsuo Umegaki, Jun-Min Yan, Xin-Bo Zhang, Hiroshi Shioyama, Nobuhiro Kuriyama, Qiang Xu* National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan article info abstract Article history: Boron- and nitrogen-based chemical hydrides are expected to be potential hydrogen Received 20 November 2008 carriers for PEM fuel cells because of their high hydrogen contents. Significant efforts have Accepted 4 January 2009 been devoted to decrease their dehydrogenation and hydrogenation temperatures and Available online 4 February 2009 enhance the reaction kinetics. This article presents an overview of the boron- and nitrogen-based compounds as hydrogen storage materials. Keywords: ª 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights Boron-based chemical hydrides reserved. Nitrogen-based chemical hydrides Hydrogen storage Dehydrogenation Hydrogenation Ammonia borane 1. Introduction in operating the system at high temperature poses an obstacle to its practical application. Chemical hydrogen Hydrogen is a globally accepted clean fuel. The use of storage materials, due to their high hydrogen contents, are hydrogen fuel cells in portable electronic devices or vehicles expected as potential hydrogen sources for fuel cells. Among requires lightweight
    [Show full text]
  • Common Name: LITHIUM ALUMINUM HYDRIDE HAZARD
    Common Name: LITHIUM ALUMINUM HYDRIDE CAS Number: 16853-85-3 RTK Substance number: 1121 DOT Number: UN 1410 Date: April 1986 Revision: November 1999 ----------------------------------------------------------------------- ----------------------------------------------------------------------- HAZARD SUMMARY * Lithium Aluminum Hydride can affect you when * Exposure to hazardous substances should be routinely breathed in. evaluated. This may include collecting personal and area * Contact can cause severe skin and eye irritation and burns. air samples. You can obtain copies of sampling results * Breathing Lithium Aluminum Hydride can irritate the from your employer. You have a legal right to this nose and throat. information under OSHA 1910.1020. * Breathing Lithium Aluminum Hydride can irritate the * If you think you are experiencing any work-related health lungs causing coughing and/or shortness of breath. Higher problems, see a doctor trained to recognize occupational exposures can cause a build-up of fluid in the lungs diseases. Take this Fact Sheet with you. (pulmonary edema), a medical emergency, with severe shortness of breath. WORKPLACE EXPOSURE LIMITS * Exposure can cause loss of appetite, nausea, vomiting, The following exposure limits are for Aluminum pyro powders diarrhea and abdominal pain. (measured as Aluminum): * Lithium Aluminum Hydride can cause headache, muscle weakness, loss of coordination, confusion, seizures and NIOSH: The recommended airborne exposure limit is coma. 5 mg/m3 averaged over a 10-hour workshift. * High exposure can affect the thyroid gland function resulting in an enlarged thyroid (goiter). ACGIH: The recommended airborne exposure limit is * Lithium Aluminum Hydride may damage the kidneys. 5 mg/m3 averaged over an 8-hour workshift. * Lithium Aluminum Hydride is a REACTIVE CHEMICAL and an EXPLOSION HAZARD.
    [Show full text]
  • A Passive Lithium Hydride Based Hydrogen Generator for Low Power Fuel Cells for Long-Duration Sensor Networks
    international journal of hydrogen energy 39 (2014) 10216e10229 Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he A passive lithium hydride based hydrogen generator for low power fuel cells for long-duration sensor networks D. Strawser, J. Thangavelautham*, S. Dubowsky Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA article info abstract Article history: This paper focuses on developing an efficient fuel storage and release method for hydrogen Received 7 November 2013 using lithium hydride hydrolysis for use in PEM fuel cells for low power sensor network Received in revised form modules over long durations. Lithium hydride has high hydrogen storage density and 2 April 2014 achieves up to 95e100% yield. It is shown to extract water vapor freely from the air to Accepted 17 April 2014 generate hydrogen and has a theoretical fuel specific energy of up to 4900 Wh/kg. A critical Available online 23 May 2014 challenge is how to package lithium hydride to achieve reaction completion. Experiments here show that thick layers of lithium hydride nearly chokes the reaction due to buildup of Keywords: lithium hydroxide impeding water transport and preventing reaction completion. A model Hydrogen generator has been developed that describes this lithium hydride hydrolysis behavior. The model Lithium hydride accurately predicts the performance of an experimental system than ran for 1400 h and PEM consists of a passive lithium hydride hydrogen generator and PEM fuel cells. These results Sensor networks power supply offer important design guidelines to enable reaction completion and build long-duration Hydrolysis lithium hydride hydrogen generators for low power applications.
    [Show full text]
  • A New Look at Lithium Hydride Chemical Biosensors Measure Brain Activity Recovering Infrastructure After a Biological Attack About the Cover
    Lawrence Livermore National Laboratory October/November 2016 Also in this issue: A New Look at Lithium Hydride Chemical Biosensors Measure Brain Activity Recovering Infrastructure after a Biological Attack About the Cover Through a historic partnership between the Department of Energy (DOE) and the National Cancer Institute (NCI), Lawrence Livermore is applying its expertise in high-performance computing (HPC) to advance cancer research and treatment. As the article beginning on p. 4 describes, the Laboratory plays a crucial role in the partnership’s three pilot programs. In particular, Livermore experts are working in collaboration with NCI and other DOE labroatories to develop more advanced algorithms for improving predictive models, computational tools for better understanding cancer intiation, and data analytics techniques to search for patterns in vast amounts of patient data. The cover art combines an artist’s rendering of circulating tumor cells in the blood of a cancer patient with computer circuitry (representing HPC) in the background. Cover design: Amy E. Henke E. Amy design: Cover About S&TR At Lawrence Livermore National Laboratory, we focus on science and technology research to ensure our nation’s security. We also apply that expertise to solve other important national problems in energy, bioscience, and the environment. Science & Technology Review is published eight times a year to communicate, to a broad audience, the Laboratory’s scientific and technological accomplishments in fulfilling its primary missions. The publication’s goal is to help readers understand these accomplishments and appreciate their value to the individual citizen, the nation, and the world. The Laboratory is operated by Lawrence Livermore National Security, LLC (LLNS), for the Department of Energy’s National Nuclear Security Administration.
    [Show full text]
  • Lithium Aluminium Hydride.Pdf
    SIGMA-ALDRICH sigma-aldrich.com Material Safety Data Sheet Version 5.0 Revision Date 03/12/2011 Print Date 09/12/2011 1. PRODUCT AND COMPANY IDENTIFICATION Product name : Aluminium lithium hydride Product Number : 531502 Brand : Aldrich Supplier : Sigma-Aldrich 3050 Spruce Street SAINT LOUIS MO 63103 USA Telephone : +1 800-325-5832 Fax : +1 800-325-5052 Emergency Phone # (For : (314) 776-6555 both supplier and manufacturer) Preparation Information : Sigma-Aldrich Corporation Product Safety - Americas Region 1-800-521-8956 2. HAZARDS IDENTIFICATION Emergency Overview OSHA Hazards Water Reactive, Target Organ Effect, Toxic by ingestion, Corrosive Target Organs Kidney, Liver, Central nervous system GHS Classification Substances, which in contact with water, emit flammable gases (Category 1) Acute toxicity, Oral (Category 3) Skin corrosion (Category 1B) Serious eye damage (Category 1) GHS Label elements, including precautionary statements Pictogram Signal word Danger Hazard statement(s) H260 In contact with water releases flammable gases which may ignite spontaneously. H301 Toxic if swallowed. H314 Causes severe skin burns and eye damage. Precautionary statement(s) P223 Keep away from any possible contact with water, because of violent reaction and possible flash fire. P231 + P232 Handle under inert gas. Protect from moisture. P280 Wear protective gloves/ protective clothing/ eye protection/ face protection. P305 + P351 + P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P310 Immediately call a POISON CENTER or doctor/ physician. P370 + P378 In case of fire: Use dry sand, dry chemical or alcohol-resistant foam for extinction. P422 Store contents under inert gas.
    [Show full text]
  • Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage
    energies Review Complex Metal Hydrides for Hydrogen, Thermal and Electrochemical Energy Storage Kasper T. Møller 1 ID , Drew Sheppard 1,2, Dorthe B. Ravnsbæk 3 ID , Craig E. Buckley 2, Etsuo Akiba 4,5,6, Hai-Wen Li 1,4,5,7,* and Torben R. Jensen 1,* 1 Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, DK-8000 Aarhus, Denmark; [email protected] (K.T.M.); [email protected] (D.S.) 2 Department of Physics and Astronomy, Fuels and Energy Technology Institute, Curtin University, GPO Box U1987, Perth, WA 6845, Australia; [email protected] 3 Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark; [email protected] 4 International Research Center for Hydrogen Energy, Kyushu University, Fukuoka 819-0395, Japan; [email protected] 5 WPI International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan 6 Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395, Japan 7 Kyushu University Platform of Inter/Transdisciplinary Energy Research, Fukuoka 819-0395, Japan * Correspondence: [email protected] (H.-W.L.); [email protected] (T.R.J.) Academic Editor: Haolin Tang Received: 18 September 2017; Accepted: 12 October 2017; Published: 18 October 2017 Abstract: Hydrogen has a very diverse chemistry and reacts with most other elements to form compounds, which have fascinating structures, compositions and properties. Complex metal hydrides are a rapidly expanding class of materials, approaching multi-functionality, in particular within the energy storage field.
    [Show full text]
  • 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
    Appendix B Classification of common chemicals by chemical band 1 1 EXHIBIT 1 2 CHEMICAL CLASSIFICATION LIST 3 4 1. Pyrophoric Chemicals 5 1.1. Aluminum alkyls: R3A1, R2A1C1, RA1C12 6 Examples: Et3A1, Et2A1C1, EtA.1111C12, Me3A1, Diethylethoxyaluminium 7 1.2. Grignard Reagents: RMgX (R=alkyl, aryl, vinyl X=halogen) 8 1.3. Lithium Reagents: RLi (R 7 alkyls, aryls, vinyls) 9 Examples: Butyllithium, Isobutylthhium, sec-Butyllithium, tert-Butyllithium, 10 Ethyllithium, Isopropyllithium, Methyllithium, (Trimethylsilyl)methyllithium, 11 Phenyllithiurn, 2-Thienyllithium, Vinyllithium, Lithium acetylide ethylenediamine 12 complex, Lithium (trimethylsilyl)acetylide, Lithium phenylacetylide 13 1.4. Zinc Alkyl Reagents: RZnX, R2Zn 14 Examples: Et2Zn 15 1.5. Metal carbonyls: Lithium carbonyl, Nickel tetracarbonyl, Dicobalt octacarbonyl 16 1.6. Metal powders (finely divided): Bismuth, Calcium, Cobalt, Hafnium, Iron, 17 Magnesium, Titanium, Uranium, Zinc, Zirconium 18 1.7. Low Valent Metals: Titanium dichloride 19 1.8. Metal hydrides: Potassium Hydride, Sodium hydride, Lithium Aluminum Hydride, 20 Diethylaluminium hydride, Diisobutylaluminum hydride 21 1.9. Nonmetal hydrides: Arsine, Boranes, Diethylarsine, diethylphosphine, Germane, 22 Phosphine, phenylphosphine, Silane, Methanetellurol (CH3TeH) 23 1.10. Non-metal alkyls: R3B, R3P, R3As; Tributylphosphine, Dichloro(methyl)silane 24 1.11. Used hydrogenation catalysts: Raney nickel, Palladium, Platinum 25 1.12. Activated Copper fuel cell catalysts, e.g. Cu/ZnO/A1203 26 1.13. Finely Divided Sulfides:
    [Show full text]
  • (12) Patent Application Publication (10) Pub. No.: US 2014/0084224 A1 Rittmeyer Et Al
    US 20140O84224A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2014/0084224 A1 Rittmeyer et al. (43) Pub. Date: Mar. 27, 2014 (54) PROCESS FOR PREPARING LITHIUM (30) Foreign Application Priority Data SULFIDE May 27, 2011 (DE) ...................... 10 2011 O76 572.7 (75) Inventors: Peter Rittmeyer, Sulzbach/Taunus (DE): Publication Classification Ulrich Wietelmann, Friedrichsdorf (DE); Uwe Lischka, Frankfurt am Main (51) Int. Cl. Bernhard Figer, Frankfurt am Main 52) U.S. C. (DE), Armin Stoll, Hemsbach (DE): (52) CPC ...................................... COIB 17/22 (2013.01) Dirk Dawidowski, Friedberg (DE) USPC ...................... 252/519.4; 423/566.2:423/511 (73) Assignee: CHEMETALL GMBH, Frankfurt am (57) ABSTRACT Main (DE) The invention relates to a novel process for preparing lithium sulfide and to the use thereof, wherein a reaction of lithium (21) Appl. No.: 14/119,980 containing strong bases with hydrogen Sulfide is undertaken in an aprotic organic solvent within the temperature range (22) PCT Filed: May 29, 2012 from -20 to 120° C. under inert conditions. The lithium Sulfide obtained by the process is used as a positive material (86). PCT No.: PCT/EP2012/06OO14 in a galvanic element or for the synthesis of Li ion-conductive S371 (c)(1), Solids, especially for the synthesis of glasses, glass ceramics (2), (4) Date: Nov. 25, 2013 or crystalline products. US 2014/0084224 A1 Mar. 27, 2014 PROCESS FOR PREPARING LITHIUM alkylene, lithium arylene, and lithium amides, and react SULFIDE according to the following equations: 0001. The invention relates to a novel method for prepar ing lithium sulfide, and use thereof.
    [Show full text]
  • Tritium Production in a Sphere of 6Lid Irradiated by 14-Mev Neutrons
    LA-731 O q-.- “- z i“ J. Tritium Production in a Sphere of 6LiD Irradiated by 14-MeV Neutrons —.. I DO NOT CIRCULATE~ PERMANENT RETENTION J i I REQUIREDBY CONTRACT — ..—. -1 1 L%%LOS ALAMOS SCIENTIFIC LABORATORY Post Office Box 1663 Los Alamos. New Mexico 87545 AnAffirmativeAction/12@OpportunityEmployer s. ● ‘lltks t’m.rl wu DIWd u M . ..ounl of work eonwrrd by the Unit.d Slates Oovernm.nl. Neither the Unkd Slates nor the Unllcd Slates lMPuimrIIt of cnrrsy, nor MY of the& rmployec% nor any 01 Owlr contractors, wbeOnlraclOm. or their .mplcweehm.k.n -y wunnty. .xon= . Imdid. ~ ✌ -“,. MY I.ld lhbl!lty .t rrwondbilkty f., tkl. .CCU=CY. oompletenew F uwfulneu of my In fommllon, ●pparatus. pmducl, or pr.xe= dlsclotd. w repmunls that IU uw wculd not Intrhw. Ptkw.ldY owned ticbk UNITCD STATES DEPARTMENT OF ENCR~V CONTRACT W-740 S-SN0. SC LA-731O UC-34C Issued: October 1978 Tritium Production in a Sphere of 6LiD Irradiated by 14-MeV Neutrons A. Hemmendinger C. E. Ragan E. R. Shunk A. N. Ellis J. M. Anaya Jon M. Wallace t- — CONTENTS ABSTRACT . ...1 PART I MEASUREMENT OF TRITIUMPRODUCTION INASPHEREOF ‘LiDIRRADL4TED BY14-MeVNEUTRONS ABSTRACT . 2 I. INTRODUCTION . 2 II. THE6LiD ASSEMBLY . 2 III. STANDARDIZATION . 4 A. General Procedure . 4 B. Backgrounds . 7 c. Thermal Activations ofLiH.. ...7 - D. Gamma-Ray Countingof’’’Au. ...8 E. Calculation ofExpectedTritium Activity . ...8 Iv. TRITIUM-PRODUCTION RESULTS . ...11 ACKNOWLEDGMENTS . ...12 APPENDIXA. TRITIUM DECAY RATES ENSAMPLES OF UNIRRADIATED’LiD ..13 APPENDIXB. CALCULATION OFVOLUME-AVERAGED NEUTRONFLUENCE . ..14 APPENDIXC. NEUTRON AND GAMMA-RAY ABSORPTION IN GOLD WIRE .
    [Show full text]
  • A Combined Theoryexperiment Analysis of the Surface Species in Lithiummediated NH3 Electrosynthesis
    Downloaded from orbit.dtu.dk on: Oct 05, 2021 A Combined TheoryExperiment Analysis of the Surface Species in LithiumMediated NH3 Electrosynthesis Schwalbe, Jay A.; Statt, Michael J.; Chosy, Cullen; Singh, Aayush R.; Rohr, Brian A.; Nielander, Adam C.; Andersen, Suzanne Zamany; McEnaney, Joshua M.; Baker, Jon G.; Jaramillo, Thomas F. Total number of authors: 12 Published in: ChemElectroChem Link to article, DOI: 10.1002/celc.201902124 Publication date: 2020 Document Version Peer reviewed version Link back to DTU Orbit Citation (APA): Schwalbe, J. A., Statt, M. J., Chosy, C., Singh, A. R., Rohr, B. A., Nielander, A. C., Andersen, S. Z., McEnaney, J. M., Baker, J. G., Jaramillo, T. F., Norskov, J. K., & Cargnello, M. (2020). A Combined TheoryExperiment Analysis of the Surface Species in LithiumMediated NH3 Electrosynthesis. ChemElectroChem, 7. https://doi.org/10.1002/celc.201902124 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
    [Show full text]
  • Lithium Amid and Lithium Hydride for Hydrogen Storage System
    Lithium Nitride for Reversible Hydrogen Storage *Takayuki Ichikawa1,2, Shigehito Isobe2, Nobuko Hanada2 and Hironobu Fujii1,2 1. Natural Science Center for Basic Research and Development, Hiroshima University, Higashi-Hiroshima 739 - 8526, Japan, 2. Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8521, Japan Abstract In this paper, we examined the basic properties in the 1:1 mixture of lithium amide LiNH2 and lithium hydride LiH as a candidate of reversible hydrogen storage materials. The thermal desorption mass spectra of the ball milled mixture without any catalysts indicated that hydrogen H2 is released in temperature range from 180 to 400 ℃ with emitting a considerable amount of ammonia NH3. On the other hand, the ball milled mixture containing a small amount of TiCl3 as a catalyst showed the most superior hydrogen storage properties among the 1:1 mixtures with a small amount of catalysts, Ni, Fe, Co metals and TiCl3 (1 mol.%). That is, the product desorbs a large amount of hydrogen (~5.5 wt.%) in the temperature from 150 to 250 ℃ under the condition of a heating rate of 5 ℃/min, but it does not desorb ammonia at all within our experimental accuracy. In addition, we confirmed that the product shows an excellent cycle retention with an effective hydrogen capacity of more than 5 wt.% and a high reaction rate until at least 3 cycles. Keywords: Hydrogen storage; Chemical hydride; Lithium amide, -imide, -hydride, -nitride; Ball milling; Ammonia; TiCl3; * Corresponding author. E-mail address: [email protected] (T. Ichikawa) 1 Introduction Recently, hydrogen energy systems have been proposed as a means to reduce greenhouse gas and other harmful emissions from stationary and mobile sources, aiming at a higher energy independence from fossil fuels.
    [Show full text]