DOCSLIB.ORG

June 1-4, 2010

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
June 1-4, 2010 Meeting of the Catalysis Science Program Chemical Sciences, Geosciences and Biosciences Division Office of Basic Energy Sciences U.S. Department of Energy Annapolis, Maryland June 1‐4, 2010 This document was produced under contract number DE-AC05-060R23100 between the U.S. Department of Energy and Oak Ridge Associated Universities. FOREWORD The 2010 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 June 1 through June 4, 2010, at the Westin Annapolis Hotel, Annapolis, Maryland. The purposes of this meeting are to discuss the recent advances in the chemical, physical and biological bases of catalysis science, to foster exchange of ideas and cooperation among participants, and to discuss the new challenges and opportunities recently emerging in energy technologies. Catalysis activities within OBES emphasize fundamental research aimed at initially understanding and finally controlling the chemical reactivity of matter in all its states. The long-term goal of this research is to discover fundamental principles and produce ever more insightful approaches to predict structure-reactivity relations. Such knowledge, integrated with advances in chemical and materials synthesis, in situ analytical instrumentation, and chemical kinetics and dynamics methods, will allow the control of chemical reactions along desired pathways. Ultimately, this new knowledge should impact the efficiency of conversion of natural resources (mass and energy) into fuels, chemicals, materials, or other forms of energy, while minimizing the impact to the environment. Special thanks go to our invited speakers and guest junior scientists, 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 for Science and Education staff for the logistical and web support and the compilation of this volume. Richard Kemp1, Elena Rybak-Akimova2 and Raul Miranda3 1 University of New Mexico and Sandia National Laboratory 2 Tufts University 3 Office of Basic Energy Sciences - U.S. Department of Energy i MEETING OVERVIEW 2010 DOE/BES Catalysis Sciences Meeting June 1–4, 2010 Annapolis, MD Time Tuesday, June 1 Wednesday, June 2 Thursday, June 3 Friday, June 4 Breakfast Breakfast Breakfast 7:00 AM Outside Senate A&B Outside Senate A&B Outside Senate A&B 8:30 Wednesday morning session Thursday morning session Friday morning session Capitol D Capitol D Capitol D 11:15 Working lunch noon Lunch 12:20 PM Lunch Outside Senate A&B Outside Senate A&B 1:00 Poster take-down Meeting adjourns 3:00 Networking Registration/Poster setup Networking Outside Senate A&B (until 6:00) 5:00 Reception Dinner Dinner Capitol C&D Capitol B&C Capitol B&C 6:00 Dinner Capitol C&D 6:15 Wednesday evening session Thursday evening session Capitol D Capitol D 7:00 Tuesday evening session Capitol C&D 8:20 Social hour / Social hour / Poster session II: Poster session III: even-numbered posters all posters Senate A&B Senate A&B 8:40 Social hour/Poster session I: odd-numbered posters Senate A&B ii AGENDA Tuesday Evening, 1 June 2010 Registration: 3:00 – 6:00 (Outside Senate A&B) Reception: 5:00 – 6:00 (Capitol C&D) Dinner: 6:00 – 7:00 (Capitol C&D) Session Chair: Thomas Rauchfuss 7:00 – 7:10 Welcoming Remarks 7:10 – 7:55 Invited Speaker: William Tolman (U Minnesota) Mechanistic Insights Into O2 and N2O Activation By Copper Complexes 7:55 – 8:40 Invited Speaker: Licheng Sun (Royal Inst Techn (KTH) Sweden) Bioinspired Molecular Catalysts for Efficient Water Oxidation Driven by Visible Light and Mechanism for O-O Bond Formation 8:40 – 10:00 Social Hour / Poster Session I (Senate A&B) Wednesday Morning, 2 June 2010 7:00 – 8:15 Breakfast (Outside Senate A&B) Session Chair: Ayusman Sen (Capitol D) 8:30 – 9:15 Invited Speaker: Philip Power (UC-Davis) Activation of Hydrogen under Ambient Conditions by Main Group Molecules 9:15 – 9:50 Dan DuBois (PNNL) A Modular Energy-Based Approach to Molecular Catalyst Design 9:50 – 10:15 Coffee Break (Outside Senate A&B) 10:15 – 10:50 Keith Woo (Iowa State U) Organometallic Chemistry and Catalysis on Metal Surfaces 10:50 – 11:25 John Hartwig (U Illinois) Chemistry of Complexes with Transition Metal-Heteroatom Bonds: Novel Insertion Chemistry and X-H Bond Activation 11:25 – 12:05 Morris Bullock (PNNL) Center for Molecular Electrocatalysis; and Brent Gunnoe (Virginia) Center for Catalytic Hydrocarbon Functionalization Overview of New Energy Frontier Research Centers 12:20 Lunch (Outside Senate A&B) iii Wednesday Evening, 2 June 2010 5:00 – 6:00 Dinner (Capitol B&C) Session Chair: Shannon Stahl (Capitol D) 6:15 – 7:00 Invited Speaker: Andrew Bocarsly (Princeton U) The Electrocatalyzed Conversion of Carbon Dioxide and Water to Alcohols 7:00 – 7:35 Roy Periana (Scripps Res Inst) Low Oxidation State Catalysts for Oxidation Reactions: Overcoming the Seeming Dilemma and Realizing the Advantages 7:35 – 7:45 Break (Outside Senate A&B) 7:45 – 8:20 Invited Speaker: Nancy Jackson (SNL, ACS President-Elect) Changing Paradigms in the Chemical Sciences 8:20 – 10:00 Social Hour / Poster Session II (Senate A&B) Thursday Morning, 3 June 2010 7:00 – 8:15 Breakfast (Outside Senate A&B) Session Chair: Lawrence Sita (Capitol D) 8:30 – 9:15 Invited Speaker: Gerard van Koten (Utrecht U) Cascade Catalysis and Homogeneous Metal Catalysts 9:15 – 9:40 Christine Thomas (Brandeis U) Early/Late Heterobimetallic Complexes Linked by Phosphinoamide Ligands: Rational Tuning of Redox Potentials and Capacity for Small Molecule Activation 9:40 – 10:05 Wendy Shaw (PNNL) Enhancing Hydrogen Production and Oxidation Catalysts with Proton Channels 10:05 – 10:40 Coffee Break (Outside Senate A&B) 10:40 – 11:15 Daniel Mindiola (Indiana U) Low-Coordinate and Terminal Nitrido Complexes of Vanadium and Titanium for N-atom Transfer Chemistry 11:15 – 11:40 John Berry (U Wisconsin) Catalytic C–H Functionalization: Synthesis of Intermediate Analogs and Tuning the Redox Properties of New Catalysts 12:00 Lunch (Outside Senate A&B) iv Thursday Evening, 3 June 2010 5:00 – 6:00 Dinner (Capitol B&C) Session Chair: Richard Finke (Capitol D) 6:15 – 7:00 Invited Speaker: Vincent Artero (Commissariat à l'Energie Atomique et aux Energies Renouvelables (CEA), France) From Hydrogenase Mimics to Noble-Metal Free Hydrogen-Evolving Electrocatalytic Nanomaterials 7:00 – 7:35 Guy Bertrand (UC-Riverside) Transition-Metal-Catalyzed Hydroamination of Non-activated Carbon- Carbon Multiple Bonds with Ammonia 7:35 – 7:45 Break (Outside Senate A&B) 7:45 – 8:20 Gerard Parkin (Columbia U) Fundamental Studies of Metal Centered Transformations Relevant to Catalysis 8:20 – 10:00 Social Hour / Poster Session III (Senate A&B) Friday Morning, 4 June 2010 7:00 – 8:15 Breakfast (Outside Senate A&B) Session Chairs: Elena Rybak-Akimova and Richard Kemp (Capitol D) 8:30 – 9:15 Invited Speaker: Philip Jessop (Queens U) Persuading CO2 to be Useful 9:15 – 9:50 John Bercaw (Caltech) Synthetic and Mechanistic Investigations of Olefin Polymerization Catalyzed by Early Transition Metal Compounds 9:50 – 10:00 Coffee Break (Outside Senate A&B) 10:00 – 10:35 Richard Kemp (U New Mexico/SNL) Direct Partial Oxidations Using Molecular Oxygen 10:35 – 11:00 Theodore Betley (Harvard U) New Methods for Small Molecule Activation 11:15 – 1:00 Working lunch: Future directions for the program. Discussion and conclusions. v vi Table of Contents Foreword ...................................................................................................i Meeting Overview .....................................................................................ii Agenda .................................................................................................... iii Table of Contents .................................................................................... vii Tuesday Evening Session Invited Speaker: William Tolman – Mechanistic Insights into O2 and N2O Activation by Copper Complexes .................................................................... 1 Invited Speaker: Licheng Sun – Bioinspired Molecular Catalysts for Efficient Water Oxidation Driven by Visible Light and Mechanism for O-O Bond Formation... 2 Wednesday Morning Session Invited Speaker: Philip Power – Activation of Hydrogen under Ambient Conditions by Main Group Molecules ............................................................... 3 Dan DuBois – A Modular Energy-Based Approach to Molecular Catalyst Design...... 6 Keith Woo – Organometallic Chemistry and Catalysis on Metal Surfaces............. 12 John Hartwig – Chemistry of Complexes with Transition Metal-Heteroatom Bonds: Novel Insertion Chemistry and X-H Bond Activation ............................. 14 Morris Bullock – Overview of the Center for Molecular Electrocatalysis ............... 17 Brent Gunnoe – Development of Transition Metal Catalysts for the Functionalization of Carbon-Hydrogen Bonds: Fundamental Studies of Catalytic Hydroarylation of Olefins ................................................................ 18 Wednesday Evening Session Invited Speaker: Andrew Bocarsly – The Electrocatalyzed Conversion of Carbon Dioxide and Water to Alcohols........................................................... 22 Roy Periana – Low Oxidation State Catalysts
Load more

Recommended publications
  • Heavier Group 2 Metal Complexes with a Flexible Scorpionate
    RSC Advances View Article Online PAPER View Journal | View Issue Heavier group 2 metal complexes with a flexible scorpionate ligand based on 2-mercaptopyridine† Cite this: RSC Adv.,2015,5,51413 Kishor Naktode,a Th. Dhileep N. Reddy,a Hari Pada Nayek,b Bhabani S. Mallik*a and Tarun K. Panda*a 2 We report the synthesis of novel alkaline earth metal complexes [k -SS-(Bmp)2M(THF)n][M¼ Ca (2), Sr (3) n ¼ 2; M ¼ Ba (4), n ¼ 3] of a flexible dihydrobis(2-thiopyridone)borate (Bmp) ligand based on 2- mercaptopyridine. Complexes 2–4 were isolated in good yield by the reaction between sodium dihydrobis(2-thiopyridone)borate, [{(Bmp)Na(THF)}2]n (1) and the corresponding alkaline earth metal diiodides in toluene at ambient temperature. The solid-state structures of the strontium and barium complexes, complexes 3 and 4 respectively, were established using single-crystal X-ray diffraction analysis. The solid-state structure of sodium complex 1 was also confirmed using X-ray techniques. The solid-state structures of complexes 3 and 4 revealed that the Bmp ligand coordinates through sulphur atoms to the metal ions in k2 fashion. The strontium ion is attached symmetrically and the barium ion is Creative Commons Attribution 3.0 Unported Licence. asymmetrically linked with the Bmp ligand, manifesting the 2-thiopyridone and pyridine-2-thiolate tautomeric form of the Bmp ligand. The strontium ion in complex 3 adopts a distorted octahedral geometry whereas the geometry around the barium ion can best be described as a distorted pentagonal Received 17th March 2015 bipyramidal.
    [Show full text]
  • Complexes Of
    www.nature.com/scientificreports OPEN Heteroleptic Copper(I) Complexes of “Scorpionate” Bis-pyrazolyl Carboxylate Ligand with Auxiliary Received: 13 December 2016 Accepted: 21 February 2017 Phosphine as Potential Anticancer Published: 24 March 2017 Agents: An Insight into Cytotoxic Mode Rais Ahmad Khan1, Mohammad Usman2, Rajakumar Dhivya3, Perumalsamy Balaji3, Ali Alsalme1, Hamad AlLohedan1,4, Farukh Arjmand2, Khalid AlFarhan1, Mohammad Abdulkader Akbarsha3, Fabio Marchetti5, Claudio Pettinari5 & Sartaj Tabassum1,2,4 New copper(I) complexes [CuCl(PPh3)(L)] (1: L = LA = 4-carboxyphenyl)bis(3,5-dimethylpyrazolyl) methane; (2: L = LB = 3-carboxyphenyl)bis(3,5-dimethylpyrazolyl)methane) were prepared and characterised by elemental analysis and various spectroscopic techniques such as FT-IR, NMR, UV–Vis, and ESI-MS. The molecular structures of complexes 1 and 2 were analyzed by theoretical B3LYP/DFT method. Furthermore, in vitro DNA binding studies were carried out to check the ability of complexes 1 and 2 to interact with native calf thymus DNA (CT-DNA) using absorption titration, fluorescence quenching and circular dichroism, which is indicative of more avid binding of the complex 1. Moreover, DNA mobility assay was also conducted to study the concentration-dependent cleavage pattern of pBR322 DNA by complex 1, and the role of ROS species to have a mechanistic insight on the cleavage pattern, which ascertained substantial roles by both hydrolytic and oxidative pathways. Additionally, we analyzed the potential of the interaction of complex 1 with DNA and enzyme (Topo I and II) with the aid of molecular modeling. Furthermore, cytotoxic activity of complex 1 was tested against HepG2 cancer cell lines.
    [Show full text]
  • Transport of Dangerous Goods
    ST/SG/AC.10/1/Rev.16 (Vol.I) Recommendations on the TRANSPORT OF DANGEROUS GOODS Model Regulations Volume I Sixteenth revised edition UNITED NATIONS New York and Geneva, 2009 NOTE The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. ST/SG/AC.10/1/Rev.16 (Vol.I) Copyright © United Nations, 2009 All rights reserved. No part of this publication may, for sales purposes, be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, electrostatic, magnetic tape, mechanical, photocopying or otherwise, without prior permission in writing from the United Nations. UNITED NATIONS Sales No. E.09.VIII.2 ISBN 978-92-1-139136-7 (complete set of two volumes) ISSN 1014-5753 Volumes I and II not to be sold separately FOREWORD The Recommendations on the Transport of Dangerous Goods are addressed to governments and to the international organizations concerned with safety in the transport of dangerous goods. The first version, prepared by the United Nations Economic and Social Council's Committee of Experts on the Transport of Dangerous Goods, was published in 1956 (ST/ECA/43-E/CN.2/170). In response to developments in technology and the changing needs of users, they have been regularly amended and updated at succeeding sessions of the Committee of Experts pursuant to Resolution 645 G (XXIII) of 26 April 1957 of the Economic and Social Council and subsequent resolutions.
    [Show full text]
  • Reversible Metalation and Catalysis with a Scorpionate-Like Metallo- Ligand in a Metal−Organic Framework Chenyue Sun, Grigorii Skorupskii, Jin-Hu Dou, Ashley M
    Communication Cite This: J. Am. Chem. Soc. 2018, 140, 17394−17398 pubs.acs.org/JACS Reversible Metalation and Catalysis with a Scorpionate-like Metallo- ligand in a Metal−Organic Framework Chenyue Sun, Grigorii Skorupskii, Jin-Hu Dou, Ashley M. Wright, and Mircea Dinca*̆ Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States *S Supporting Information these supports makes any attempts to understand and control − ABSTRACT: The installation of metallo-ligands in the active site difficult.12 16 metal−organic frameworks (MOFs) is an effective One class of hybrid solids that provide exceptional structural means to create site-isolated metal centers toward uniformity are metal−organic frameworks (MOFs).17 These single-site heterogeneous catalysis. Although trispyrazoly- materials’ ability to preserve a molecule-like coordination borate (Tp) and tripyrazolylmethane (Tpm) form one of environment in a rigid and well-defined solid is highlighted by the most iconic classes of homogeneous catalysts, neither their utility as single-site heterogeneous catalysts18,19 and as has been used as a metallo-ligand for the generation of catalyst promoters.20 The anionic Tp itself is mimicked by the MOFs thus far. Here, we show that upon in situ coordination environment of secondary building units (SBUs) I metalation with Cu , a tricarboxylated Tpm ligand reacts of a series of azolate-based MOFs.21,22 Metal substitution at 23,24 with ZrOCl2 to generate a new MOF exhibiting neutral these SBUs provided heterogeneous catalysts for a range of scorpionate-like chelating sites. These sites undergo for processes including ethylene oligomerization, polymerization, − facile demetalation and remetalation with retention of and C−H amination.25 27 It is harder, however, to devise or I crystallinity and porosity.
    [Show full text]
  • I. MATRIX ISOLATION of 1,1-DIAZENES II. DISTANCE, TEMPERATURE, and DYNAMIC SOLVENT EFFECTS on ELECTRON TRANSFER REACTIONS Thesis
    I. MATRIX ISOLATION OF 1,1-DIAZENES II. DISTANCE, TEMPERATURE, AND DYNAMIC SOLVENT EFFECTS ON ELECTRON TRANSFER REACTIONS Thesis by James Edward Hanson In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 1990 (Submitted September 8, 1989) 11 © 1990 James Edward Hanson All rights Reserved ill Acknowledgements I would like to thank my advisor, Peter Dervan , for his enthusiasm and support during my studies at Caltech. I would also like to thank Professor John Hopfield for his availability when I needed assistance with the theoretical complexities of the electron transfer work. I am deeply indebted to Lutfur "Zeta" Khundkar and Joe Perry for their expert assistance and collaboration in making measurements and understanding the implications of the results. Al Sylwester was extremely helpful in my first year as I began to work on 1,1-diazenes, and Alvin Joran and Burt Leland made my transition to the electron transfer project relatively simple. I should also thank those in the Dervan group who helped me with synthetic problems, especially John Griffin and Warren Wade. I appreciated discussions with some of the electron transfer experts at Caltech: Professor Rudy Marcus, Dave Beratan, Jose Onuchic, Dave Malerba, and Tad Fox. There were many times when the men in the chemistry shops provided invaluable assistance--you guys are the best! There are many who made my stay at Caltech enjoyable--I'll remember skiing with John and Linda Griffin and Heinz Moser, basketball (and marathons!) with Dave Kaisaki, tennis with Erich Uffelmann, and late night conversations with Kevin Luebke.
    [Show full text]
  • Ger'g .Tyson Jr
    July 14, 1964 ' G. N. TYSON, JR 3,140,582 ROCKET PROPULSION METHOD USING BORON AND NITROGEN COMPOUNDS Filed April 14, 1959 Ger'g .Tyson Jr. INVENTOR. I", u .12) ATTORNEYS 3,l4,582 Patented July 14,, 1964 2 The nitrogen containing compound and the boron con 3,140,582 taining compound are reacted in such proportions that all ROCKET PROPULSION METHOD USING BORON of the nitrogen and all of the boron react to produce AND NOGEN COMPOUNDS boron nitride, the carbon is released as elemental carbon George N. Tyson, Jr., Claremont, Calif., assignor to Olin Mathieson Chemical Corporation, a corporation of and large volumes of hydrogen gas are produced. Virginia Nitrogen containing compounds which can be employed Filed Apr. 14, 1959, Ser. No. 806,396 as reactants include the saturated hydronitrogens such 20 Claims. (Cl. 60-354) as ammonia, hydrazine, triazane, tetrazane; the unsaturated hydronitrogens such as diimide, triazene, tetrazene, iso This invention relates to a method for producing large 10 tetrazene, ammonium azide, hydrazine azide, and hydra volumes of hot gases in a short period of time, which zoic acid; alkyl hydrazines such as methyl hydrazine, un large volumes of hot gases are useful for many purposes symmetrical dimethyl hydrazine, ethyl hydrazine, unsym including imparting thrust to jet propelled devices such metrical diethyl hydrazine; alkylamines including mixed al as rockets. kylamines such as methylamine, dimethylamine, trimeth Jet propelled devices are essentially of two types: those 15 ylamine, ethylamine, diethylamine, triethylarnine, methyl which depend upon an external source for a portion of ethyl amine, n-propylamine, isopropylamine, di-n-propyl the propellant, and those in which the propellant is en amine, tri-n-propylamine, methyl propyl amine, ethyl prop tirely contained within the device.
    [Show full text]
  • Studies of a Dirhodium Tetraphosphine Catalyst for Hydroformylation And
    Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2012 Studies of a dirhodium tetraphosphine catalyst for hydroformylation and aldehyde-water shift ac talysis Aaron Rider Barnum Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Chemistry Commons Recommended Citation Barnum, Aaron Rider, "Studies of a dirhodium tetraphosphine catalyst for hydroformylation and aldehyde-water shift catalysis" (2012). LSU Doctoral Dissertations. 3998. https://digitalcommons.lsu.edu/gradschool_dissertations/3998 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. STUDIES OF A DIRHODIUM TETRAPHOSPHINE CATALYST FOR HYDROFORMYLATION AND ALDEHYDE-WATER SHIFT CATALYSIS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College In partial fulfillment of the Requirements for the degree of Doctor of Philosophy In The Department of Chemistry by Aaron Rider Barnum B.S. Loyola University New Orleans, 2007 December 2012 ACKNOWLEDGEMENTS I would like to thank my family, for without their encouragements and support I would not be where I am today. To my parents, Otis and Cindy Barnum, thank you for everything throughout the years. To my grandmother Teruko, you are responsible for two things I hold very dear to my heart: inspiring me to become the scientist and chemist I am today and also for keeping me in touch with my Japanese heritage.
    [Show full text]
  • Steven Kealey
    Synthesis and Coordination Chemistry of Scorpionate Ligands and their Applications in 11C—Positron Emission Tomography Steven Kealey Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy Supervisor: Prof. N. J. Long Department of Chemistry Imperial College London April 2008 STATEMENT OF COPYRIGHT The copyright of this thesis rests with the author. No quotation from it should be published without the prior written consent of the author and information derived from it should be acknowledged appropriately. DECLARATION The work described in this thesis was carried out in the Department of Chemistry, Imperial College London, between October 2004 and December 2007. The entire body of work is my own unless otherwise stated to the contrary and has not been submitted previously for a degree at this or any other university. i ABSTRACT This thesis is concerned with the synthesis and coordination chemistry of a range of poly(pyrazolyl)borate scorpionate' ligands and examines their suitability in facilitating rapid [11C]carbonylation reactions to form radiotracers for application in positron emission tomography (PET). The synthesis of a series of tris(pyrazolyl)borate (Tp) ligands and their corresponding copper(I) carbonyl complexes is described. The copper(I) carbonyls were formed by reaction of potassium Tp salts with copper chloride in the presence of carbon monoxide. The second part of this thesis concerns the use of a copper(I)-Tp system for selectively solubilising "CO from nitrogen-rich gas streams for subsequent use in palladium-catalysed carbonylation reactions between amines and aryl-halides to form amides. These reactions were performed on a microfluidic device and in Schlenk apparatus using unlabelled carbon monoxide.
    [Show full text]
  • Graphene Supported Rhodium Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution Reaction Ameerunisha Begum1*, Moumita Bose2 & Golam Moula2
    www.nature.com/scientificreports OPEN Graphene Supported Rhodium Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution Reaction Ameerunisha Begum1*, Moumita Bose2 & Golam Moula2 Current research on catalysts for proton exchange membrane fuel cells (PEMFC) is based on obtaining higher catalytic activity than platinum particle catalysts on porous carbon. In search of a more sustainable catalyst other than platinum for the catalytic conversion of water to hydrogen gas, a series of nanoparticles of transition metals viz., Rh, Co, Fe, Pt and their composites with functionalized graphene such as RhNPs@f-graphene, CoNPs@f-graphene, PtNPs@f-graphene were synthesized and characterized by SEM and TEM techniques. The SEM analysis indicates that the texture of RhNPs@f- graphene resemble the dispersion of water droplets on lotus leaf. TEM analysis indicates that RhNPs of <10 nm diameter are dispersed on the surface of f-graphene. The air-stable NPs and nanocomposites were used as electrocatalyts for conversion of acidic water to hydrogen gas. The composite RhNPs@f- graphene catalyses hydrogen gas evolution from water containing p-toluene sulphonic acid (p-TsOH) at an onset reduction potential, Ep, −0.117 V which is less than that of PtNPs@f-graphene (Ep, −0.380 V) under identical experimental conditions whereas the onset potential of CoNPs@f-graphene was at Ep, −0.97 V and the FeNPs@f-graphene displayed onset potential at Ep, −1.58 V. The pure rhodium nanoparticles, RhNPs also electrocatalyse at Ep, −0.186 V compared with that of PtNPs at Ep, −0.36 V and that of CoNPs at Ep, −0.98 V.
    [Show full text]
  • Anagostic Interactions Under Pressure: Attractive Or Repulsive? Wolfgang Scherer *[A], Andrew C
    Manuscript Click here to download Manuscript: manuscript_final.pdf ((Attractive or repulsive?)) DOI: 10.1002/anie.200((will be filled in by the editorial staff)) Anagostic Interactions under Pressure: Attractive or Repulsive? Wolfgang Scherer *[a], Andrew C. Dunbar [a], José E. Barquera-Lozada [a], Dominik Schmitz [a], Georg Eickerling [a], Daniel Kratzert [b], Dietmar Stalke [b], Arianna Lanza [c,d], Piero Macchi*[c], Nicola P. M. Casati [d], Jihaan Ebad-Allah [a] and Christine Kuntscher [a] The term “anagostic interactions” was coined in 1990 by Lippard preagostic interactions are considered to lack any “involvement of 2 and coworkers to distinguish sterically enforced M•••H-C contacts dz orbitals in M•••H-C interactions” and rely mainly on M(dxz, yz) (M = Pd, Pt) in square-planar transition metal d8 complexes from o V (C-H) S-back donation.[3b] attractive, agostic interactions.[1a] This classification raised the fundamental question whether axial M•••H-C interaction in planar The first observation of unusual axial M•••H-C interaction in 8 8 d -ML4 complexes represent (i) repulsive anagostic 3c-4e M•••H-C planar d -ML4 complexes was made by S. Trofimenko, who interactions[1] (Scheme 1a) or (ii) attractive 3c-4e M•••H-C pioneered the chemistry of transition metal pyrazolylborato hydrogen bonds[2] (Scheme 1b) in which the transition metal plays complexes.[5,6] Trofimenko also realized in 1968, on the basis of the role of a hydrogen-bond acceptor (Scheme 1b). The latter NMR studies, that the shift of the pseudo axial methylene protons in 3 bonding description is related to another bonding concept which the agostic species [Mo{Et2B(pz)2}(K -allyl)(CO)2] (1) (pz = describes these M•••H-C contacts in terms of (iii) pregostic or pyrazolyl; allyl = H2CCHCH2) “is comparable in magnitude but [3] preagostic interactions (Scheme 1c) which are considered as being different in direction from that observed in Ni[Et2B(pz)2]2” (2) “on the way to becoming agostic, or agostic of the weak type”.[4] (Scheme 2).[6,7] Scheme 1.
    [Show full text]
  • Dinuclear Gold Complexes Supported by Wide Bite Angle Diphosphines for Preorganization-Induced Selective Dual-Gold Catalysis
    UvA-DARE (Digital Academic Repository) Dinuclear Gold Complexes Supported by Wide Bite Angle Diphosphines for Preorganization-Induced Selective Dual-Gold Catalysis Lankelma, M.; Vreeken, V.; Siegler, M.A.; van der Vlugt, J.I. DOI 10.3390/inorganics7030028 Publication date 2019 Document Version Final published version Published in Inorganics License CC BY Link to publication Citation for published version (APA): Lankelma, M., Vreeken, V., Siegler, M. A., & van der Vlugt, J. I. (2019). Dinuclear Gold Complexes Supported by Wide Bite Angle Diphosphines for Preorganization-Induced Selective Dual-Gold Catalysis. Inorganics, 7(3), [28]. https://doi.org/10.3390/inorganics7030028 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:02 Oct 2021 inorganics Article Dinuclear Gold Complexes Supported by Wide Bite Angle Diphosphines for Preorganization-Induced Selective Dual-Gold Catalysis Marianne Lankelma 1, Vincent Vreeken 1, Maxime A.
    [Show full text]
  • Organometallics Study Meeting H.Mitsunuma 1
    04/21/2011 Organometallics Study Meeting H.Mitsunuma 1. Crystal field theory (CFT) and ligand field theory (LFT) CFT: interaction between positively charged metal cation and negative charge on the non-bonding electrons of the ligand LFT: molecular orbital theory (back donation...etc) Octahedral (figure 9-1a) d-electrons closer to the ligands will have a higher energy than those further away which results in the d-orbitals splitting in energy. ligand field splitting parameter ( 0): energy between eg orbital and t2g orbital 1) high oxidation state 2) 3d<4d<5d 3) spectrochemical series I-< Br-< S2-< SCN-< Cl-< N -,F-< (H N) CO, OH-< ox, O2-< H O< NCS- <C H N, NH < H NCH CH NH < bpy, phen< NO - - - - 3 2 2 2 5 5 3 2 2 2 2 2 < CH3 ,C6H5 < CN <CO cf) pairing energy: energy cost of placing an electron into an already singly occupied orbital Low spin: If 0 is large, then the lower energy orbitals(t2g) are completely filled before population of the higher orbitals(eg) High spin: If 0 is small enough then it is easier to put electrons into the higher energy orbitals than it is to put two into the same low-energy orbital, because of the repulsion resulting from matching two electrons in the same orbital 3 n ex) (t2g) (eg) (n= 1,2) Tetrahedral (figure 9-1b), Square planar (figure 9-1c) LFT (figure 9-3, 9-4) - - Cl , Br : lower 0 (figure 9-4 a) CO: higher 0 (figure 9-4 b) 2. Ligand metal complex hapticity formal chargeelectron donation metal complex hapticity formal chargeelectron donation MR alkyl 1 -1 2 6-arene 6 0 6 MH hydride 1 -1 2 M MX H 1 -1 2 halogen 1 -1 2 M M -hydride M OR alkoxide 1 -1 2 X 1 -1 4 M M -halogen O R acyl 1 -1 2 O 1 -1 4 M R M M -alkoxide O 1-alkenyl 1 -1 2 C -carbonyl 1 0 2 M M M R2 C -alkylidene 1 -2 4 1-allyl 1 -1 2 M M M O C 3-carbonyl 1 0 2 M R acetylide 1 -1 2 MMM R R C 3-alkylidine 1 -3 6 M carbene 1 0 2 MMM R R M carbene 1 -2 4 R M carbyne 1 -3 6 M CO carbonyl 1 0 2 M 2-alkene 2 0 2 M 2-alkyne 2 0 2 M 3-allyl 3 -1 4 M 4-diene 4 0 4 5 -cyclo 5 -1 6 M pentadienyl 1 3.
    [Show full text]