DOCSLIB.ORG

Where Are We to Day in the Overlap Between Homogeneous And

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Frontiers in Molecular Catalysis Science PR 2 X Ir + H2 PR 2 Zeo l i t e (H+ - S Z2 5 ; 25 % w/) > 600 turnovers re f lux, b. p. 20 5 °C up to 99% selectivity Meeting of the Catalysis Science Program Chemical Sciences, Geosciences, and Biosciences Division Office of Basic Energy Sciences U.S. Department of Energy Annapolis, Maryland May 18-21, 2008 Frontiers in Molecular Catalysis Science Meeting of the Catalysis Science Program Chemical Sciences, Geosciences and Biosciences Division Office of Basic Energy Scineces, U. S. Department of Energy Annapolis, MD ─ May 18-21, 2008 Cover figures (top left to bottom right): 1. S. Nguyen, J. Hupp: chiral epoxidation of chromene catalyzed by chiral (salen)Mn in metal organic framework 2. C. Hill, et al.: water oxidation catalyst, Rb8K2[{Ru4O4(OH)2(H2O)4}(γ- SiW10O36)2]·25H2O 3. A. Goldman: tandem dehydrogenation catalysis with a pincer-ligated iridium complex 4. R. Bergman, K. Raymond: “nanovessels” for controlling stereo-, chemo- and/or regioselectivity 5. V. Lin et al.: multifunctional mesoporous nanoparticles for selective catalysis and biofuel applications 6. A. Sygula, P. W. Rabideau: double concave hydrocarbon catcher for buckminsterfullerene C60 This document was produced under contract number DE-AC05-060R23100 between the U.S. Department of Energy and Oak Ridge Associated Universities. FOREWORD The 2008 Catalysis Science Program Meeting is sponsored by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences (OBES), U.S. Department of Energy. It is being held on May 18-21, 2008, at the Doubletree Hotel Annapolis, Annapolis, MD. The purposes of this meeting are to discuss the recent advances in organometallic, inorganic and bioinspired chemistry and catalysis, to foster exchange of ideas and cooperation among participants, and to discuss the new opportunities for catalysis and chemical transformations at the interfaces with other disciplines and technologies, including nanoscience, hydrogen fuel generation and storage, solar energy conversion and bioinspired chemistry. Catalysis activities within OBES emphasize fundamental research aimed at understanding and controlling the chemical reactivity of fluid and condensed matter. The long-term goal of this research is to discover the fundamental principles and develop the techniques to predict structure-reactivity relations. Such knowledge, integrated with advances in synthesis, instrumentation, characterization, and theory, will help us to control chemical reactions along desired pathways. Ultimately, this new knowledge will result in chemical and materials processes to efficiently convert fossil and renewable resources, or to generate, convert and store energy, with minimum impact to our environment. Special thanks go to our invited speakers, who will expose us to recent advances in their fields, to the program investigators and their students, postdocs, and collaborators, for their dedication to the continuous success and visibility of the OBES Catalysis Science Program, and to the session moderators, for their invaluable help. We also thank the Oak Ridge Institute of Science and Education staff, Ms. Margaret Lyday and other contributing staff members of ORISE for the logistical and web support and the compilation of this volume. Andreja Bakac1, Aaron Sadow1, Michael Chen2 and Raul Miranda2 1Ames Laboratory and Department of Chemistry, Iowa State University Ames, IA 2Chemical Sciences, Geosciences and Biosciences Division Office of Basic Energy Sciences U.S. Department of Energy i AGENDA Sunday Evening, 18 May 2008 Session Chair: William Evans (California-Irvine) 5:30 – 6:45 Dinner 7:00 – 7:10 Welcoming Remarks 7:10 – 7:55 Invited Talk: Catalysis by Design: A Predictive Approach of Heterogeneous Catalysis via Surface Organometallic Chemistry Jean-Marie Basset (Laboratoire de Chimie Organométallique de Surface) 7:55 – 8:30 Nanocluster Catalysts Formation and Stabilization Fundamental Studies Richard Finke (Colorado State University) 8:30 – 11:00 Social Hour / Poster Session Odd-Numbered Posters* *All posters may be set up starting on Sunday 4:00 pm, will stay posted during the entire meeting, and must be taken down by Tuesday midnight at the latest. Poster presenters must stand by their poster on Sunday (odd-numbered) and Monday (even-numbered). All poster presenters are encouraged to circulate and interact but be available for questions on the Tuesday session. Tom Autrey - Control of Hydrogen Release and P1 Uptake in Condensed Phases Perla B. Balbuena - Theory-Guided Design of Nano- P3 Nanoscale Multimetallic Nanocatalysts for Fuel Cells Perla B. Balbuena - Modeling Catalyzed Growth of P5 Single-Wall Carbon Nanotubes Robert G. Bergman - Exploratory and Mechanistic P7 Investigations of C-H Activation Reactions and their Applications to Catalysis and Organic Synthesis Theodore A. Betley - New Approaches to Driving P9 Multielectron Redox Chemistry Paul J. Chirik - Understanding Nitrogen Fixation P11 iii Robert H Crabtree - Bifunctional Ligands for En- P13 hanced Selectivity in Organometallic Catalysis Sheng Dai - Colloidal Deposition Synthesis of P15 Supported Gold Nanocatalysts Based on Au-Fe3O4 Dumbbell Nanoparticles for CO Oxidation Jeffrey W. Elam - Atomic Layer Deposition Synthesis P17 of Nanostructured Membrane Catalysts James A. Franz - An Energy-Based Approach to P19 Developing Interfacial Catalysts: Thermochemistry, Kinetics and Theory of Catalytic Transformations Michel R. Gagné - Selective Approaches to the P21 Activation of Carbohydrates T. Brent Gunnoe - Transition Metal Catalyzed P23 Hydro-arylation of Multiple Bonds: Exploration of Second Generation Ruthenium Catalysts and Extension to Copper Systems William D. Jones – Transition Metal Activation and P25 Functionalization of Carbon-Hydrogen Bonds Richard A. Kemp - Direct Epoxidations Using P27 Molecular Oxygen Cora E. MacBeth - Novel Ligand Platforms for P29 Transition Metal Catalyzed C-H Oxidation Reactions Daniel J. Mindiola - Catalytic Prospects Involving P31 the Carboamination and Hydrophosphination of Alkynes Oleg V. Ozerov - Catalysis of C-F activation by P33 Highly Electrophilic Si Compounds Dmitry E. Polyansky - Transition Metal Complexes as P35 Artificial NADH Analogs: Towards Photochemical Reduction of Carbon Dioxide Thomas B. Rauchfuss - Supramolecular Ensembles P37 in Catalysis Lawrence T. Scott - High Temperature Chemistry of P41 Aromatic Hydrocarbons iv Peter C. Stair - Nanostructured Membrane Catalysis P43 T. Don Tilley - Molecular Precursor Methods for the P45 Controlled Generation of Active and Selective Catalytic Sites on an Oxide Surface L. Keith Woo – Gold Metal-Catalyzed Reactions of P47 Isocyanides and CO with Amines and Oxygen Monday Morning, 19 May 2008 Session Chair: Paul Sharp (Missouri-Columbia) 7:00 – 8:15 Breakfast 8:30 – 9:15 Invited Talk: Multifunctional Mesoporous Nanoparticles for Selective Catalysis and Biofuel Applications Victor Lin (Iowa State/Ames Laboratory) 9:15 – 9:50 Transition Metal Mediated Transformations of Small Molecules Ayusman Sen (Pennsylvania State University) 9:50 – 10:20 Coffee Break 10:20 – 10:55 Coordinative Supramolecular Catalysis Joseph Hupp (Northwestern University) 10:55 – 11:30 ‘Flexible’ Heterogenization of (Salen) Mn Complexes for Catalyzing Selective Olefin Epoxidation—Lessons from Homogeneous and Biological Catalysis SonBinh Nguyen (Northwestern University) 11:30 – 11:50 Poster talk: Homolytic and Heterolytic S-H Bond Energies in Homogeneous Mo2S4 Complexes Aaron Appel, Pacific Northwest National Laboratory 12:00 Lunch Monday Evening, 19 May 2008 Session Chair: Paul Chirik (Cornell) 5:00 – 6:00 Dinner v 6:15 – 7:00 Invited Talk: Biocatalysis for Fuels and Industrial Chemicals: Enzymes, Whole Cells and Beyond Doug Cameron (Khosla Ventures, BioOils, LLC) 7:00 – 7:35 Silane Activation on a Single-Site Oxorhenium(V) Oxazoline Catalyst: A New Mechanistic Paradigm for Hydrogen Production and Hydrosilation Mahdi Abu-Omar (Purdue University) 7:35 – 7:45 Break 7:45 – 8:20 Mechanisms of Organometallic Copper Oxidase Reactions Shannon Stahl (University of Wisconsin-Madison) 8:20 – 8:40 Poster talk: Ancillary Oxazolinylboron Ligands for Transition Metal Centers Aaron Sadow (Iowa State/Ames Laboratory) 8:40 – 11:00 Social Hour / Poster Session Even-Numbered Posters Andreja Bakac - Thermodynamics of Oxygen P2 Activation by Transition Metal Complexes Guillermo C. Bazan - Catalysts for Selective Olefin P4 Oligomerization and Polymerization John E. Bercaw - Synthetic and Mechanistic P6 Investigations of Olefin Polymerization Catalyzed by Early Transition Metal Compounds K. N. Raymond, R. G. Bergman - Selective Organic P8 and Organometallic Reactions in Water-Soluble Host-Guest Supramolecular Systems R. Morris Bullock - New Bio-Inspired Molecular P10 Catalysts for Hydrogen Oxidation and Hydrogen Production Malcolm H. Chisholm - Mechanistic and Synthetic P12 Studies Aimed at the Development of Single-Site Metal Alkoxide Catalysts for the Generation of Polyesters and Polycarbonates vi Richard M. Crooks - Understanding Multimetallic P14 Catalysts using Dendrimer-Encapsulated Nano- Particles W. Nicholas Delgass - Catalyst Design by Discovery P16 Informatics – Olefin Polymerization over Single-Site Catalysts William J. Evans - Advancing Chemistry with f P18 Elements Etsuko Fujita - Water Oxidation by a Ruthenium P20 Complex with Non-Innocent Quinone Ligands: Possible Formation of an O−O Bond at a Low Oxidation State of the Metal Alan S. Goldman - Alkane Dehydrogenation and P22 Tandem
Recommended publications
  • Opportunities for Catalysis in the 21St Century

    Opportunities for Catalysis in the 21St Century

    Opportunities for Catalysis in The 21st Century A Report from the Basic Energy Sciences Advisory Committee BASIC ENERGY SCIENCES ADVISORY COMMITTEE SUBPANEL WORKSHOP REPORT Opportunities for Catalysis in the 21st Century May 14-16, 2002 Workshop Chair Professor J. M. White University of Texas Writing Group Chair Professor John Bercaw California Institute of Technology This page is intentionally left blank. Contents Executive Summary........................................................................................... v A Grand Challenge....................................................................................................... v The Present Opportunity .............................................................................................. v The Importance of Catalysis Science to DOE.............................................................. vi A Recommendation for Increased Federal Investment in Catalysis Research............. vi I. Introduction................................................................................................ 1 A. Background, Structure, and Organization of the Workshop .................................. 1 B. Recent Advances in Experimental and Theoretical Methods ................................ 1 C. The Grand Challenge ............................................................................................. 2 D. Enabling Approaches for Progress in Catalysis ..................................................... 3 E. Consensus Observations and Recommendations..................................................
  • Preparation and Characterization of Iridium Hydride and Dihydrogen Complexes Relevant to Biomass Deoxygenation

    Preparation and Characterization of Iridium Hydride and Dihydrogen Complexes Relevant to Biomass Deoxygenation

    Preparation and Characterization of Iridium Hydride and Dihydrogen Complexes Relevant to Biomass Deoxygenation Jonathan M. Goldberg A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Washington 2017 Reading Committee: D. Michael Heinekey, Chair Karen I. Goldberg, Chair Brandi M. Cossairt Program Authorized to Offer Degree: Department of Chemistry © Copyright 2017 Jonathan M. Goldberg University of Washington Abstract Preparation and Characterization of Iridium Hydride and Dihydrogen Complexes Relevant to Biomass Deoxygenation Jonathan M. Goldberg Chairs of the Supervisory Committee: Professor D. Michael Heinekey Professor Karen I. Goldberg Department of Chemistry This thesis describes the fundamental organometallic reactivity of iridium pincer complexes and their applications to glycerol deoxygenation catalysis. These investigations provide support for each step of a previously proposed glycerol deoxygenation mechanism. Chapter 1 outlines the motivations for this work, specifically the goal of using biomass as a chemical feedstock over more common petroleum-based sources. A discussion of the importance of transforming glycerol to higher value products, such as 1,3-propanediol, is discussed. Chapter 2 describes investigations into the importance of pincer ligand steric factors on the coordination chemistry of the iridium metal center. Full characterization of a five-coordinate iridium-hydride complex is presented; this species was previously proposed to be a catalyst resting state for glycerol deoxygenation. Chapter 3 investigates hydrogen addition to R4(POCOP)Ir(CO) R4 3 t i R4 R4 3 [ POCOP = κ -C6H3-2,6-(OPR2)2 for R = Bu, Pr] and (PCP)Ir(CO) [ (PCP) = κ -C6H3-2,6- t i (CH2PR2)2 for R = Bu, Pr] to give cis- and/or trans-dihydride complexes.
  • Rational Ligand Design for U(VI) and Pu(IV)* by Géza Szigethy BA

    Rational Ligand Design for U(VI) and Pu(IV)* by Géza Szigethy BA

    Rational Ligand Design for U(VI) and Pu(IV)* by Géza Szigethy B.A. (Princeton University), 2004 A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemistry in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Kenneth N. Raymond, Chair Professor Richard A. Andersen Professor Garrison Sposito Fall 2009 * This research and the ALS are supported by the Director, Office of Science, Office of Basic Energy Sciences (OBES), and the OBES Division of Chemical Sciences, Geosciences, and Biosciences of the U.S. Department of Energy at LBNL under Contract No. DE-AC02- 05CH11231. Rational Ligand Design for U(VI) and Pu(IV) by Géza Szigethy B.A. (Princeton University), 2004 A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemistry in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Kenneth N. Raymond, Chair Professor Richard A. Andersen Professor Garrison Sposito Fall 2009 Rational Ligand Design for U(VI) and Pu(IV) Copyright © 2009 Géza Szigethy Abstract Rational Ligand Design for U(VI) and Pu(IV) by Géza Szigethy Doctor of Philosophy in Chemistry University of California, Berkeley Professor Kenneth N. Raymond, Chair Nuclear power is an attractive alternative to hydrocarbon-based energy production at a time when moving away from carbon-producing processes is widely accepted as a significant developmental need. Hence, the radioactive actinide power sources for this industry are necessarily becoming more widespread, which is accompanied by the increased risk of exposure to both biological and environmental systems.
  • 1 the Structure and Reactivity of Single and Multiple

    1 the Structure and Reactivity of Single and Multiple

    1 1 The Structure and Reactivity of Single and Multiple Sites on Heterogeneous and Homogeneous Catalysts: Analogies, Differences, and Challenges for Characterization Methods Adriano Zecchina , Silvia Bordiga , and Elena Groppo 1.1 Introduction The content of this book is specifi cally devoted to a description of the complexity of the catalytic centers (both homogeneous and heterogeneous) viewed as nanoma- chines for molecular assembling. Although the word “ nano ” is nowadays some- what abused, its use for catalysts science (as nanoscience) is fully justifi ed. It is a matter of fact that (i) to perform any specifi c catalytic action, the selective catalyst must necessarily possess sophisticated structure where substrates bonds are broken and formed along a specifi c path and (ii) the relevant part of this structure, usually constituted by a metal center or metal cluster surrounded by a sphere of ligands or by a solid framework or by a portion of functionalized surface, often reaches the nanometric dimension. As it will emerge from the various chapters, this vision is valid for many types of selective catalysts including catalysts for hydrogenation, polymerization, olygomerization, partial oxidation, and photocata- lytic solar energy conversion. Five chapters are devoted to the above - mentioned reactions. From the point of view of the general defi nition, homogeneous and heterogeneous selective catalysts can be treated in the same way. As homogeneous selective catalysts are concerned, the tridimensional structure surrounding the metal center can be organized with cavitand shape, while for heterogeneous cata- lysts the selectivity is the result of an accurate design and synthesis of the frame- work structures (often microporous and crystalline) where the sites are anchored.
  • Osmium(II)–Bis(Dihydrogen) Complexes Containing Caryl,CNHC– Chelate Ligands: Preparation, Bonding Situation, and Acidity

    Osmium(II)–Bis(Dihydrogen) Complexes Containing Caryl,CNHC– Chelate Ligands: Preparation, Bonding Situation, and Acidity

    Osmium(II)–bis(Dihydrogen) Complexes Containing Caryl,CNHC– Chelate Ligands: Preparation, Bonding Situation, and Acidity. Tamara Bolaño,† Miguel A. Esteruelas,*,† Israel Fernández,‡ Enrique Oñate,† Adrián Palacios,† Jui-Yi Tsai,√ and Chuanjun Xia√ †Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Centro de Innova- ción en Química Avanzada (ORFEO – CINQA), Universidad de Zaragoza – CSIC, 50009 Zaragoza, Spain ‡Departamento de Química Orgánica, Facultad de Ciencias Químicas, Centro de Innovación en Química Avanzada (ORFEO – CINQA), Universidad Complutense de Madrid, 28040 Madrid, Spain √Universal Display Corporation, 375 Phillips Boulevard, Ewing, New Jersey 08618, United States Supporting Information Placeholder i ABSTRACT: The hexahydride complex OsH6(P Pr3)2 (1) reacts with the BF4-salts of 1-phenyl-3-methyl-1-H-benzimidazolium, 1- phenyl-3-methyl-1-H-5,6-dimethyl-benzimidazolium, and 1-phenyl-3-methyl-1-H-imidazolium to give the respective trihydride- 2 i osmium(IV) derivatives OsH3( -Caryl,CNHC)(P Pr3)2 (2–4). The protonation of these compounds with HBF4·OEt2 produces the re- 2 2 i duction of the metal center and the formation of the bis(dihydrogen)-osmium(II) complexes [Os( -Caryl,CNHC)(η -H2)2(P Pr3)2]BF4 (5–7). DFT calculations using AIM and NBO methods reveal that the Os–NHC bond of the Os-chelate link tolerates a significant π- backdonation from a doubly occupied dπ(Os) atomic orbital to the pz atomic orbital of the carbene carbon atom. The π-accepting capacity of the NHC unit of the Caryl,CNHC-chelate ligand, which is higher than those of the coordinated aryl group and phosphine ligands, enhances the electrophilicity of the metal center activating one of the coordinated hydrogen molecules of 5–7 towards the water heterolysis.
  • Selectivity of C-H Activation and Competition Between C-H and C-F Bond Activation at Fluorocarbons

    Selectivity of C-H Activation and Competition Between C-H and C-F Bond Activation at Fluorocarbons

    This is a repository copy of Selectivity of C-H activation and competition between C-H and C-F bond activation at fluorocarbons. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/133766/ Version: Accepted Version Article: Eisenstein, Odile, Milani, Jessica and Perutz, Robin N. orcid.org/0000-0001-6286-0282 (2017) Selectivity of C-H activation and competition between C-H and C-F bond activation at fluorocarbons. Chemical Reviews. pp. 8710-8753. ISSN 0009-2665 https://doi.org/10.1021/acs.chemrev.7b00163 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ revised May 2017 Selectivity of C-H activation and competition between C-H and C-F bond activation at fluorocarbons Odile Eisenstein,* ‡ Jessica Milani, and Robin N. Perutz* ‡ Institut Charles Gerhardt, UMR 5253 CNRS Université Montpellier, cc 1501, Place E. Bataillon, 34095 Montpellier, France and Centre for Theoretical and Computational Chemistry (CTCC), Department of Chemistry, University of Oslo, P.O.
  • 1 5.03, Inorganic Chemistry Prof. Daniel G. Nocera Lecture 11

    1 5.03, Inorganic Chemistry Prof. Daniel G. Nocera Lecture 11

    5.03, Inorganic Chemistry Prof. Daniel G. Nocera Lecture 11 Apr 11: Hydride and Dihydrogen Complexes – – 2 Hydride and dihydrogen are both 2e donors, H (1s ) and H2 (σ1s2) Hydride complexes are synthesized by: (1) Replace halide with hydride using hydride transfer reagents: (2) Heterolytic cleavage of a dihydrogen complex: (3) Oxidative-addition of hydrogen to a metal complex: There are some general features of H2 oxidative-addition: • cis addition – – • 16e complexes or less add H2 (since 2e s are added to the metal complex) • bimolecular rate law (rate = k [IrL2Cl(CO)] [H2]) ‡ • ∆H = 11 kcal/mol (little H–H stretch in the transition state recall that ‡ BDE(H2) = 104 kcal/mol), and a ∆S = 21 eu – – – – • rate decreases along the series X = I > Br > Cl (100 ; 14 : 0.9) • little isotope effect, kH / kD = 1.09 1 For the oxidative-addition reaction, there are two possibilities for the transition state: 1 an H2 intermediate 2 a three-center transition state Both reaction pathways are viable for oxidative-addition (and the reverse reaction, reductive-elimination). For some metal complexes, the “arrested” addition product can be isolated—the dihydrogen complex is obtained as a stable species that can be put in a bottle. Kubas first did this in 1984 with the following reaction: 2 Several observables identify this as an authentic dihydrogen complex vs. a dihydride: • d(H—H) = 0.84 Å (as measured from neutron diffraction). This distance is near the bond distance of free H2, d(H—H) = 0.7414 Å. –1 • a symmetric H2 vibration is observed, ν(H—H) = 2,690 cm , as compared –1 to ν(H—H) = 4,300 cm in free H2.
  • Structural Analysis and Separation of Lanthanides With

    Structural Analysis and Separation of Lanthanides With

    Full Paper Chemistry—A European Journal doi.org/10.1002/chem.202002653 & CoordinationChemistry The Earlier the Better:Structural Analysis and Separation of Lanthanides with Pyrroloquinoline Quinone HenningLumpe+,[a] Annika Menke+,[a] Christoph Haisch,[b] Peter Mayer,[a] Anke Kabelitz,[c] Kirill V. Yusenko,[c] Ana Guilherme Buzanich,[c] Theresa Block,[d] Rainer Pçttgen,[d] Franziska Emmerling,[c] and Lena J. Daumann*[a] Abstract: Lanthanides (Ln) are critical raw materials,howev- ronment.The complex crystallizes as an inversion symmetric er,their mining and purification have aconsiderable nega- dimer,Eu2PQQ2,with binding of Eu in the biologically rele- tive environmental impact andsustainable recycling and vant pocket of PQQ. LnPQQ and Ln1Ln2PQQ complexes separation strategies for these elements are needed. In this were characterized by using inductively coupled plasma study,the precipitationand solubility behavior of Ln com- mass spectrometry (ICP-MS), infrared (IR) spectroscopy, 151Eu- plexes with pyrroloquinoline quinone (PQQ), the cofactor of Mçssbauer spectroscopy,X-ray total scattering, andextend- recently discovered lanthanide (Ln) dependent methanol de- ed X-ray absorption fine structure (EXAFS). It is shown that a hydrogenase (MDH)enzymes, is presented. In this context, natural enzymatic cofactor is capable to achieveseparation the molecular structure of abiorelevant europium PQQ com- by precipitationofthe notoriously similar,and thusdifficult plex was for the first time elucidated outsideaprotein envi- to separate, lanthanides to some extent. Introduction also called “vitamins, or seeds of technology” and the global demand of rare earth oxides is growing steadily.[1] Unlike their Rare earth elements (REE) include the elements 21Sc, 39Yand name suggests, REE are not particularly rare and the occur- 57La, in addition to the 14 lanthanides (Ln) from 58Ce to 71Lu.
  • Heterogeneous Catalytic Oligomerization of Ethylene

    Heterogeneous Catalytic Oligomerization of Ethylene

    Heterogeneous Catalytic Oligomerization of Ethylene Oliver Dennis Jan A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Washington 2017 Reading Committee: Fernando Resende, Chair Rick Gustafson Anthony Dichiara Program Authorized to Offer Degree: School of Environmental and Forest Sciences © Copyright 2017 Oliver Dennis Jan ii University of Washington Abstract Heterogeneous Catalytic Oligomerization of Ethylene Oliver Dennis Jan Chair of the Supervisory Committee: Assistant Professor Fernando Resende School of Environmental and Forest Sciences Throughout this work, we report results for the oligomerization of ethylene over Ni-Hβ in a packed bed reactor. We performed a parameterized study over temperature (30ºC-190ºC), pressure (8.5-25.6 bar), and weighted hourly space velocity (2.0-5.5 hr-1). We observed that the ethylene conversion increased with reaction pressure due primarily to the slower velocities at higher pressures. Increasing the temperature of the reactor led to the formation of larger oligomers and coke, but its effect on the conversion was small. The space velocity played an important role on ethylene conversion and product selectivity, with higher conversions observed at lower space velocities and higher selectivities to butene at higher space velocities. We also conducted a long experiment to determine the activity of the Ni-Hβ catalyst over 72 hours-on-stream at 19.0 bar partial pressure of ethylene, 120ºC, and 3.1 hr-1 WHSV. We observed that catalyst deactivation occurred only during the startup period largely due to coke formation. Despite this initial iii deactivation, negligible coke formation occurred after 8 hours time-on-stream, as the conversion remained steady at 47% for the duration of the experiment.
  • Molecular Beam Epitaxy in the Lithium-Niobium-Oxygen System

    Molecular Beam Epitaxy in the Lithium-Niobium-Oxygen System

    MOLECULAR BEAM EPITAXY IN THE LITHIUM-NIOBIUM-OXYGEN SYSTEM by Mario Petrucci Department of Electrical and Electronic Engineering, University College London. A thesis submitted to University College, University of London for the degree of Doctor of Philosophy. October, 1989 1 ProQuest Number: 10610929 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10610929 Published by ProQuest LLC(2017). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 To the memory of my father, Vincenzo Petrucci. 'We work not only to produce But to give value to time." Eugene Delacroix "Oh, Mr. Scientist: you take what you see And fashion a wondrous soliloquy; But greater magic is forged in what you write: Where night becomes day and day becomes night!" 2 ABSTRACT The N b -L i-0 materials system offers an extensive combination of properties useful to integrated optics. N b ^ and L iN b 03 already have applications in waveguiding devices, such as electro-optic modulators, Fresnel lenses, and SAW transducers. In several cases, however, it would be desirable to grow these oxides on lattice-matched substrates as epitaxial thin films of controlled composition, crystallinity, and thickness: this thesis describes work aimed at achieving this goal.
  • Basic Research Needs for Catalysis Science

    Basic Research Needs for Catalysis Science

    Basic Research Needs for Catalysis Science Report of the Basic Energy Sciences Workshop on Basic Research Needs for Catalysis Science to Transform Energy Technologies May 8–10, 2017 Image courtesy of Argonne National Laboratory. DISCLAIMER This report was prepared as an account of a workshop sponsored by the U.S. Department of Energy. Neither the United States Government nor any agency thereof, nor any of their employees or officers, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of document authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Copyrights to portions of this report (including graphics) are reserved by original copyright holders or their assignees, and are used by the Government’s license and by permission. Requests to use any images must be made to the provider identified in the image credits. This report is available in pdf format at https://science.energy.gov/bes/community-resources/reports/ REPORT OF THE BASIC RESEARCH NEEDS WORKSHOP FOR CATALYSIS SCIENCE Basic Research Needs for Catalysis Science TO TRANSFORM ENERGY TECHNOLOGIES Report from the U.S. Department of Energy, Office of Basic Energy Sciences Workshop May 8–10, 2017, in Gaithersburg, Maryland CHAIR: ASSOCIATE CHAIRS: Carl A.
  • Low Cost/Waste Catalyst for Fatty Acid Methyl Ester Production

    Low Cost/Waste Catalyst for Fatty Acid Methyl Ester Production

    Article Number: 2AEBF76 A Paper presented at the 39th CSN Annual International Conference, Workshop and Exhibition, Rivers State University of Science and Technology, Port Harcourt, Nigeria. 18th – 23rd September 2016 Copyright ©2018 Author(s) retain the copyright of this article Conference Proceedings http://www.proceedings.academicjournals.org/ Full Length Research Paper Low cost/waste catalyst for fatty acid methyl ester production M. O. Ekeoma1*, P. A. C. Okoye2 and V. I. E. Ajiwe2 1Department of Chemistry, College of Physical and Applied Sciences, Michael Okpara University of Agriculture, Umudike, P. M. B. 7267, Umuahia, Abia State, Nigeria. 2Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria. Non-edible crude karanj (Pongamia pinnata) oil (CKO) with high free fatty acid (FFA) content was used as effective renewable feedstock for fatty acid methyl ester (FAME) production. Calcium feldspar clay, a rare compositional variety of plagioclase clay, a low cost, abundant earth resource, containing over 90% CaO and belonging to the class of anorthite clay was used as heterogeneous catalyst in direct conversion of high FFA crude karanj oil to fatty acid methyl esters. The efficiency of the catalyst was made possible by the structural rearrangement of the mixed metal oxides' content of the catalyst at prolonged high temperatures, a behaviour characteristic of glass transitions and properties of amorphous phases of plagioclase feldspar, and thus was transformed into solid acid particles such as acidic mesoporous aluminium silicate mixed oxides. Optimum FAME yield of 98.97% was obtained at 4 h reaction time, 6 wt% catalyst loading, 9:1 methanol to CKO molar ratio and at methanol reflux temperature.