Periodic Table of the Elements of Green and Sustainable Chemistry
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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. -
Photophoretic Spectroscopy in Atmospheric Chemistry – High-Sensitivity Measurements of Light Absorption by a Single Particle
Atmos. Meas. Tech., 13, 3191–3203, 2020 https://doi.org/10.5194/amt-13-3191-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Photophoretic spectroscopy in atmospheric chemistry – high-sensitivity measurements of light absorption by a single particle Nir Bluvshtein, Ulrich K. Krieger, and Thomas Peter Institute for Atmospheric and Climate Science, ETH Zurich, 8092, Switzerland Correspondence: Nir Bluvshtein ([email protected]) Received: 28 February 2020 – Discussion started: 4 March 2020 Revised: 30 April 2020 – Accepted: 16 May 2020 – Published: 18 June 2020 Abstract. Light-absorbing organic atmospheric particles, the UV–vis wavelength range, attributing them with a nega- termed brown carbon, undergo chemical and photochemi- tive (cooling) radiative effect. However, light-absorbing or- cal aging processes during their lifetime in the atmosphere. ganic aerosol, termed brown carbon (BrC), with wavelength- The role these particles play in the global radiative balance dependent light absorption (λ−2 − λ−6) in the UV–vis wave- and in the climate system is still uncertain. To better quan- length range (Chen and Bond, 2010; Hoffer et al., 2004; tify their radiative forcing due to aerosol–radiation interac- Kaskaoutis et al., 2007; Kirchstetter et al., 2004; Lack et al., tions, we need to improve process-level understanding of ag- 2012b; Moosmuller et al., 2011; Sun et al., 2007), may be the ing processes, which lead to either “browning” or “bleach- dominant light absorber downwind of urban and industrial- ing” of organic aerosols. Currently available laboratory tech- ized areas and in biomass burning plumes (Feng et al., 2013). -
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. -
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. -
Atmospheric Chemistry
Atmospheric Chemistry John Lee Grenfell Technische Universität Berlin Atmospheres and Habitability (Earthlike) Atmospheres: -support complex life (respiration) -stabilise temperature -maintain liquid water -we can measure their spectra hence life-signs Modern Atmospheric Composition CO2 Modern Atmospheric Composition O2 CO2 N2 CO2 N2 CO2 Modern Atmospheric Composition O2 CO2 N2 CO2 N2 P 93bar 1bar 6mb 1.5bar surface CO2 Tsurface 735K 288K 220K 94K Early Earth Atmospheric Compositions Magma Hadean Archaean Proterozoic Snowball CO2 Early Earth Atmospheric Compositions Magma Hadean Archaean Proterozoic Snowball Silicate CO2 CO2 N2 N2 Steam H2ON2 O2 O2 CO2 Additional terrestrial-type atmospheres Jurassic Earth Early Mars Early Venus Jungleworld Desertworld Waterworld Superearth Modern Atmospheric Composition Today we will talk about these CO2 Reading List Yuk Yung (Caltech) and William DeMore “Photochemistry of Planetary Atmospheres” Richard P. Wayne (Oxford) “Chemistry of Atmospheres” T. Gredel and Paul Crutzen (Mainz) “Chemie der Atmosphäre” Processes influencing Photochemistry Photons Protection Delivery Escape Clouds Photochemistry Surface OCEAN Biology Volcanism Some fundamentals… ALKALI METALS The Periodic Table NOBLE GASES One outer electron Increasing atomic number 8 outer electrons: reactive Rows called PERIODS unreactive GROUPS: similar Halogens chemical C, Si etc. have 4 outer electrons properties SO CAN FORM STABLE CHAINS Chemical Structure and Reactivity s and p orbitals d orbitals The Aufbau Method works OK for the first 18 elements -
Chapter 1 – Introduction
1 Chapter 1 – Introduction 1.1 – Scientific Background Knowledge of gas phase compounds and their chemical reactions are pivotal to our understanding of chemistry. The conditions these molecules are in can vary dramatically, from temperatures as low as 10 K in the depths of the interstellar medium, to more than 1000 K in the combustion of hydrocarbons in engines. The chemistry in these systems is dominated by highly reactive, unstable compounds, leading to fast and complex chemistry occurring. In order to accurately understand these systems, we must be able to observe these unstable species and measure the kinetics of their formation and destruction. While molecular spectra and reaction rate constants of these reactive compounds can be computed with theoretical calculations, they must be benchmarked with experimental measurements to determine their accuracy. To that end, one major focus in experimental gas phase chemistry is to better understand these unstable molecules and their reactions in systems such as atmospheric chemistry and astrochemistry. 1.1a – Atmospheric Chemistry Understanding Earth’s atmosphere and the chemistry behind it has been a major topic in gas phase chemistry since the mid-20th century, when the impact of fossil fuel usage and air pollution resulting from the Industrial Revolution became apparent. The dominant molecule in Earth’s atmosphere is N2 (77% of the atmosphere) followed by O2 (21%) and argon (1%). The remaining components are largely stable molecules, such as CO2 and H2O. 2 Figure 1.1: The average temperature (left) and pressure (right) profiles of the Earth’s lower atmosphere, consisting of the troposphere and stratosphere. -
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. -
Clusters, Catalysis, and Materials: Kinetic, Superatomand
Frontiers in Chemical Physics Seminar Series Professor Will Castleman Presenting: Clusters, Catalysis, and Materials: Kinetic, Superatom and Isoelectronic Concepts Abstract During the course of investigating the reactivity and structure of metal and metal-compound clusters, we discovered the ability to mimic elements of the periodic table using selected species termed “superatoms”. The findings are being extended to binary metallic and compound systems, where both electronic and geometric structures are identified as playing a role in governing stability and the presence of reactive centers, the main subject of this lecture. As the behavior of clusters can be controlled by size and composition, the superatoms offer the potential to create unique compounds with tailored properties where each atom makes a difference. Having demonstrated the feasibility of this approach, one of the prime objectives of our current research is to lay the foundation for forming new nanoscale materials via techniques of cluster assembly utilizing these “elements” as the building blocks, utilizing knowledge we acquire about cluster reactions and properties which serve to identify promising species. This pursuit is viewed as one of the most promising frontiers in nanoscale materials research. Date: May 10th It is found that clusters of selected composition, stoichiometry, size and charge-state provide ideal media for investigating fundamental mechanisms of heterogeneous catalysis, especially for oxidation reactions. The interplay Location: EMSL AUD and unification of the ideas and concepts that enable the identification of catalytic mechanisms and the design of superatoms mimicking elements of the periodic table will be discussed, also with attention given to quantifying Time: 11:00 AM concepts through the isoelectronic principle.. -
Abiogenesis and Photostimulated Heterogeneous Reactions in The
Abiogenesis and Photostimulated Heterogeneous synthesize organic species in Interstellar Space on the Reactions in the Interstellar Medium and in the surface of dust particles (as they were on primitive Earth). Primitive Earth’s Atmosphere. Some peculiar features of heterogeneous photocatalytic Relevance to the Genesis of Life systems, namely (i) the considerable red shift of the spectral range of a given photoreaction compared with N. Serpone,1, 2 A. Emeline,1 V. Otroshchenko,3 one in homogeneous phase and (ii) the effect of spectral and V. Ryabchuk 4 selectivity of photocatalysts (5), favor the synthesis of 1 Department of Chemistry & Biochemistry, Concordia organic substrates under the above-mentioned natural University, Montreal (QC), Canada H3G 1M8. conditions. The first feature utilizes a considerably larger 2 Dipartimento di Chimica Organica, Universita di Pavia, fraction of Solar Energy than is otherwise possible in Pavia, Italia. homogeneous photochemical reactions. The second 3 Bach Institute of Biochemistry, Russian Academy of feature influences the dependence of the relative chemical Sciences, Moscow, Russia. yields of different products of a given reaction on the 4 Department of Physics, University of St.-Petersburg, wavelength of the actinic radiation. In particular, the St. Petersburg 198504, Russia. products of complete and partial oxidation of methane and other hydrocarbons result principally from the Studies of micrometeoritic particles captured by Earth photoexcitation of metal-oxide photocatalysts in the (i.e. ) absorption bands (strong at different geological times and discovered in Antarctica fundamental intrinsic have deduced that many organic substances necessary for absorption of UV and of blue light). More complex the Origin of Life on Earth are synthesized in Interstellar organic compounds are formed under irradiation of the catalysts in the absorption bands (weak to Space and are subsequently transported to Earth by extrinsic meteorites, comets, and cosmic dust (1).