The Electron Factor in Catalysis on Metals Electrocatalysis on Non-Metallic Surfaces
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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.................................................. -
Dehydrogenation by Heterogeneous Catalysts
Dehydrogenation by Heterogeneous Catalysts Daniel E. Resasco School of Chemical Engineering and Materials Science University of Oklahoma Encyclopedia of Catalysis January, 2000 1. INTRODUCTION Catalytic dehydrogenation of alkanes is an endothermic reaction, which occurs with an increase in the number of moles and can be represented by the expression Alkane ! Olefin + Hydrogen This reaction cannot be carried out thermally because it is highly unfavorable compared to the cracking of the hydrocarbon, since the C-C bond strength (about 246 kJ/mol) is much lower than that of the C-H bond (about 363 kJ/mol). However, in the presence of a suitable catalyst, dehydrogenation can be carried out with minimal C-C bond rupture. The strong C-H bond is a closed-shell σ orbital that can be activated by oxide or metal catalysts. Oxides can activate the C-H bond via hydrogen abstraction because they can form O-H bonds, which can have strengths comparable to that of the C- H bond. By contrast, metals cannot accomplish the hydrogen abstraction because the M- H bonds are much weaker than the C-H bond. However, the sum of the M-H and M-C bond strengths can exceed the C-H bond strength, making the process thermodynamically possible. In this case, the reaction is thought to proceed via a three centered transition state, which can be described as a metal atom inserting into the C-H bond. The C-H bond bridges across the metal atom until it breaks, followed by the formation of the corresponding M-H and M-C bonds.1 Therefore, dehydrogenation of alkanes can be carried out on oxides as well as on metal catalysts. -
Sustainable Catalysis
Green Process Synth 2016; 5: 231–232 Book review Sustainable catalysis DOI 10.1515/gps-2016-0016 Sustainable catalysis provides an excellent in-depth over- view of the applications of non-endangered elements in Michael North (Ed.) all aspects of catalysis from heterogeneous to homogene- Sustainable catalysis: with non-endangered metals ous, from catalyst supports to ligands. The Royal Society of Chemistry, 2015 Four volumes of the book series are divided into RSC Green Chemistry series nos. 38–41 two sub-topics devoted to (i) metal-based catalysts and Part 1 (ii) catalysts without metals or other endangered ele- Print ISBN: 978-1-78262-638-1 ments. Each sub-topic comprises of two books due to the PDF eISBN: 978-1-78262-211-6 detailed analysis of catalytic applications described. All Part 2 chapters are written by the world-leading researchers in Print ISBN: 978-1-78262-639-8 the area; however, covering far beyond the scope of their PDF eISBN: 978-1-78262-642-8 immediate research interests, which makes the book par- ticularly valuable for a wide range of readers. Sustainable catalysis: without metals or other Sustainable catalysis: with non-endangered metals endangered elements begins with a very brief chapter which describes the Part 1 concept of elemental sustainability, overviewing the Print ISBN: 978-1-78262-640-4 abundance of the critical elements and perspectives on PDF eISBN: 978-1-78262-209-3 sustainable catalysts. The chapters follow the groups of EPUB eISBN: 978-1-78262-752-4 the periodic table from left to right, from alkaline metals to Part 2 lead spanning 22 chapters. -
Report to DPR from the Panel Conducting the Peer Review of The
1 May 7, 2011 Administrator Lisa Jackson United States Environmental Protection Agency Ariel Rios Building 1200 Pennsylvania Avenue, N. W. Mail Code: 1101A Washington, DC 20460 Re: Docket ID number EPA-HQ-OPP-2010-0541, Petition to Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide) Dear Administrator Jackson, We are pleased to see that US EPA has decided to reconsider the registration of methyl iodide for its use as a soil fumigant pesticide. We remain concerned about the wisdom of widespread dispersion of methyl iodide into the environment and support the petition to cancel all uses of this chemical as a pesticide. It is one of the more hazardous chemicals used in research labs and in the chemical industry, and it seems counterintuitive that EPA would work on one hand to prevent and document relatively small releases of methyl iodide used in research and chemical manufacturing, while permitting what will likely be millions of pounds to be used annually in agriculture near homes, schools and workplaces. In our letter to EPA of September 24, 2007, (which we sent a copy of to you in February of 2009), we strongly recommended that EPA not register methyl iodide, but if the Agency chose to do so, we recommended that US EPA obtain an external scientific peer review of the risk assessment. While EPA did not commission such a review, the state of California has conducted its own risk assessment and did commission a Scientific Review Committee (SRC) to evaluate US EPA’s and the California Department of Pesticide Regulation’s (DPR’s) risk assessments. -
The Early History of Catalysis
The Early History of Catalysis By Professor A. J. B. Robertson Department of Chemistry, King’s College, London One hundred and forty years ago it was Berzelius proceeded to propose the exist- possible for one man to prepare an annual ence of a new force which he called the report on the progress of the whole of “catalytic force” and he called “catalysis” the chemistry, and for many years this task was decomposition of bodies by this force. This undertaken by the noted Swedish chemist is probably the first recognition of catalysis J. J. Berzelius for the Stockholm Academy of as a wide-ranging natural phenomenon. Sciences. In his report submitted in 1835 and Metallic catalysts had in fact been used in published in 1836 Berzelius reviewed a num- the laboratory before 1800 by Joseph Priestley, ber of earlier findings on chemical change in the discoverer of oxygen, and by the Dutch both homogeneous and heterogeneous sys- chemist Martinus van Marum, both of whom tems, and showed that these findings could be made observations on the dehydrogenation of rationally co-ordinated by the introduction alcohol on metal catalysts. However, it seems of the concept of catalysis. In a short paper likely that these investigators regarded the summarising his ideas on catalysis as a new metal merely as a source of heat. In 1813, force, he wrote (I): Louis Jacques Thenard discovered that ammonia is decomposed into nitrogen and “It is, then, proved that several simple or compound bodies, soluble and insoluble, have hydrogen when passed over various red-hot the property of exercising on other bodies an metals, and ten years later, with Pierre action very different from chemical affinity. -
Physical Organic Chemistry
CHM 8304 Physical Organic Chemistry Catalysis Outline: General principles of catalysis • see section 9.1 of A&D – principles of catalysis – differential bonding 2 Catalysis 1 CHM 8304 General principles • a catalyst accelerates a reaction without being consumed • the rate of catalysis is given by the turnover number • a reaction may alternatively be “promoted” (accelerated, rather than catalysed) by an additive that is consumed • a heterogeneous catalyst is not dissolved in solution; catalysis typically takes place on its surface • a homogeneous catalyst is dissolved in solution, where catalysis takes place • all catalysis is due to a decrease in the activation barrier, ΔG‡ 3 Catalysts • efficient at low concentrations -5 -4 -5 – e.g. [Enz]cell << 10 M; [Substrates]cell < 10 - 10 M • not consumed during the reaction – e.g. each enzyme molecule can catalyse the transformation of 20 - 36 x 106 molecules of substrate per minute • do not affect the equilibrium of reversible chemical reactions – only accelerate the rate of approach to equilibrium end point • most chemical catalysts operate in extreme reaction conditions while enzymes generally operate under mild conditions (10° - 50 °C, neutral pH) • enzymes are specific to a reaction and to substrates; chemical catalysts are far less selective 4 Catalysis 2 CHM 8304 Catalysis and free energy • catalysis accelerates a reaction by stabilising a TS relative to the ground state ‡ – free energy of activation, ΔG , decreases – rate constant, k, increases • catalysis does not affect the end point -
Concepts and Tools for Mechanism and Selectivity Analysis in Synthetic Organic Electrochemistry
Concepts and tools for mechanism and selectivity analysis in synthetic organic electrochemistry Cyrille Costentina,1,2 and Jean-Michel Savéanta,1 aUniversité Paris Diderot, Sorbonne Paris Cité, Laboratoire d’Electrochimie Moléculaire, Unité Mixte de Recherche Université–CNRS 7591, 75205 Paris Cedex 13, France Contributed by Jean-Michel Savéant, April 2, 2019 (sent for review March 19, 2019; reviewed by Robert Francke and R. Daniel Little) As an accompaniment to the current renaissance of synthetic organic sufficient to record a current-potential response but small electrochemistry, the heterogeneous and space-dependent nature of enough to leave the substrates and cosubstrates (of the order of electrochemical reactions is analyzed in detail. The reactions that follow one part per million) almost untouched. Competition of the the initial electron transfer step and yield the products are intimately electrochemical/chemical events with diffusional transport under coupled with reactant transport. Depiction of the ensuing reactions precisely mastered conditions allows analysis of the kinetics profiles is the key to the mechanism and selectivity parameters. within extended time windows (from minutes to submicroseconds). Analysis is eased by the steady state resulting from coupling of However, for irreversible processes, these approaches are blind on diffusion with convection forced by solution stirring or circulation. reaction bifurcations occurring beyond the kinetically determining Homogeneous molecular catalysis of organic electrochemical reactions step, which are precisely those governing the selectivity of the re- of the redox or chemical type may be treated in the same manner. The same benchmarking procedures recently developed for the activation action. This is not the case of preparative-scale electrolysis accom- of small molecules in the context of modern energy challenges lead to panied by identification and quantitation of products. -
Driving Innovation Through Materials Research Proceedings of the 1996
Driving Innovation Through Materials Research Proceedings of the 1996 Solid State Sciences Committee Forum N A T I O L R E S C H U S O L I D T A E C N M Driving Innovation Through Materials Research Proceedings of the 1996 Solid State Sciences Committee Forum Solid State Sciences Committee Board on Physics and Astronomy Commission on Physical Sciences, Mathematics, and Applications National Research Council NATIONAL ACADEMY PRESS Washington, D.C. 1996 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences. -
The Golden Fleece, Science Education, and U.S. Science Policy1
The Golden Fleece, Science Education, 1 and U.S. Science Policy Richard C. Atkinson President University of California was pleased to accept Roger Hahn’s kind invitation to participate in I this colloquium series. It gave me an opportunity to rethink some events I was associated with at the National Science Foundation (NSF) in the 1970s. I would like to review briefly U.S. science policy since World War II from the perspective of the National Science Foundation, and in particular from the narrower perspective of science education and the social sciences at NSF. This is a personal account, not a schol- arly one, and I would be delighted if my remarks were to stimulate some aspiring young historians to undertake a more careful study of the events I am going to discuss. My story begins with World War II and the remarkable success of U.S. science in the war effort—a critical factor in our victory. President Roosevelt’s science adviser, Vannevar Bush, had been a long-term member of the faculty at the Massachusetts Institute of Technology; he was one of the key people responsible for building the quality of that institution. Bush had a close personal relationship with Roosevelt. Near the end of the war the president asked him to define a plan for American science in the postwar period. That request led to Bush’s landmark report, Science, The Endless Frontier, one of the great documents of American history. The Bush report defined science policy for the post-World War II era. What was the nature of that report? No summary could do justice to Bush’s masterful analysis, but essentially he made three principal arguments about the future of the U.S. -
Electrochemistry and Photoredox Catalysis: a Comparative Evaluation in Organic Synthesis
molecules Review Electrochemistry and Photoredox Catalysis: A Comparative Evaluation in Organic Synthesis Rik H. Verschueren and Wim M. De Borggraeve * Department of Chemistry, Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200F, box 2404, 3001 Leuven, Belgium; [email protected] * Correspondence: [email protected]; Tel.: +32-16-32-7693 Received: 30 March 2019; Accepted: 23 May 2019; Published: 5 June 2019 Abstract: This review provides an overview of synthetic transformations that have been performed by both electro- and photoredox catalysis. Both toolboxes are evaluated and compared in their ability to enable said transformations. Analogies and distinctions are formulated to obtain a better understanding in both research areas. This knowledge can be used to conceptualize new methodological strategies for either of both approaches starting from the other. It was attempted to extract key components that can be used as guidelines to refine, complement and innovate these two disciplines of organic synthesis. Keywords: electrosynthesis; electrocatalysis; photocatalysis; photochemistry; electron transfer; redox catalysis; radical chemistry; organic synthesis; green chemistry 1. Introduction Both electrochemistry as well as photoredox catalysis have gone through a recent renaissance, bringing forth a whole range of both improved and new transformations previously thought impossible. In their growth, inspiration was found in older established radical chemistry, as well as from cross-pollination between the two toolboxes. In scientific discussion, photoredox catalysis and electrochemistry are often mentioned alongside each other. Nonetheless, no review has attempted a comparative evaluation of both fields in organic synthesis. Both research areas use electrons as reagents to generate open-shell radical intermediates. Because of the similar modes of action, many transformations have been translated from electrochemical to photoredox methodology and vice versa. -
President's Daily Diary Collection (Box 85) at the Gerald R
Scanned from the President's Daily Diary Collection (Box 85) at the Gerald R. Ford Presidential Library THE WHITE HOUSE THE DAILY DIARY OF PRESIDENT GERALD R. FORD PLACE DAY BEGAN DATE (Mo., Day, Yr.) THE WHITE HOUSE DECEMBER 16, 1976 WASHINGTON, D.C. TIME DAY 7:25 a.m. THURSDAY TIME il "C ~ ~~ ACTIVITY I----~----I ~ ~ In Out .. ~ 7:25 The President had breakfast. 7:55 The President went to the doctor's office. 8:00 The president went to the Oval Office. 8:18 8:30 The President met with: Wally A. Criswell, Pastor of the First Baptist Church, Dallas, Texas Robert Denny, General Secretary of the Baptist World Alliance, Washington, D.C. Richard S. Brannon, Staff Assistant 8:33 9:00 The President met with: George Bush, Director of the Central Intelligence Agency (CIA) Lt. Gen. Brent Scowcroft, Assistant for National Security Affairs 9:05 9:20 The President met with his Assistant, Richard B. Cheney. 9:35 10:15 The President met with: Henry A. Kissinger, Secretary of State Lt. Gen. Scowcroft 10:28 R The President was telephoned by Congressman John J. Rhodes (R-Arizona). The call was not cmmpleted. 10:34 The President went to the Cabinet Room. 10:34 11:30 The President participated in a meeting with members of the President's Committee on Science and Technology and other science leaders. For a list of attendees, see APPENDIX "A." Members of the press, in/out 11: 30 The President returned to the Oval Office. The President met to discuss the status of Kincheloe Air Force Base in Michigan with: 11:40 12:05 John 0 •. -
May 25, 1963, Approved the Following
THE UNIVERSITY OF TEXAS Office of the Chancellor May 7, 1963 TO THE HONORABLE BOARD OF REGENTS OF THE UNIVERSITY OF TEXAS Mrs. Johnson and Gentlemen: The Budget Dockets prepared by the component institutions listed below are herewith submitted, with my recommendation for approval, for consideration at the meeting of the Board of Regents on May 24 - 25, 1963. Main University M. D. Anderson Hospital and Texas Western College Tumor Institute Medical Branch Southwestern Medical School Dental Branch The following changes affecting Central Administration budgetary operations are recommended for approval by the Board of Regents. RECOMMENDED AMENDMENTS --TO THE 1962-63 BUDGET University Development Board 1. Transfer $1.250, > from the Universitv Develooment Board Publishing- and Mailing account to the University Development Board Clerical Assistants account. In prior years some of the part-time clerical employees hired on a temporary basis for special publishing and mailing projects were paid from the Publishing and Mailing account. Since the Auditor has requested that all part-time employees be paid from the Clerical Assistants account, this transfer will be necessary in order to meet clerical costs resulting from various mailing programs during the rest of this year. (RBC 87) University Lands, Geology 2. Effective April 19, 1963, accept the resignation of Mr. James Roland Mollard, Petroleum Engineer, at an annual salary rate of $6,468. (RBC 89) APPROPRIATION FOR MISCELUNEOUS COSTS - PERMANENT UNIVERSITY FUND BONDS - P -___> SERIES 1963 3, At- the April, 1963, meeting of the Board of Regents the subject bond issue in the amount of $4,000,000 was authorized and the bond counsel was named.