Water Splitting by Heterogeneous Catalysis
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Characterization of Copper Electroplating And
CHARACTERIZATION OF COPPER ELECTROPLATING AND ELECTROPOLISHING PROCESSES FOR SEMICONDUCTOR INTERCONNECT METALLIZATION by JULIE MARIE MENDEZ Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Advisor: Dr. Uziel Landau Department of Chemical Engineering CASE WESTERN RESERVE UNIVERSITY August, 2009 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis/dissertation of _____________________________________________________ candidate for the ______________________degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. TABLE OF CONTENTS Page Number List of Tables 3 List of Figures 4 Acknowledgements 9 List of Symbols 10 Abstract 13 1. Introduction 15 1.1 Semiconductor Interconnect Metallization – Process Description 15 1.2 Mechanistic Aspects of Bottom-up Fill 20 1.3 Electropolishing 22 1.4 Topics Addressed in the Dissertation 24 2. Experimental Studies of Copper Electropolishing 26 2.1 Experimental Procedure 29 2.2 Polarization Studies 30 2.3 Current Steps 34 2.3.1 Current Stepped to a Level below Limiting Current 34 2.3.2 Current Stepped to the Limiting -
Surface Reactions and Chemical Bonding in Heterogeneous Catalysis
Surface reactions and chemical bonding in heterogeneous catalysis Henrik Öberg Doctoral Thesis in Chemical Physics at Stockholm University 2014 Thesis for the Degree of Doctor of Philosophy in Chemical Physics Department of Physics Stockholm University Stockholm 2014 c Henrik Oberg¨ ISBN 978-91-7447-893-8 Abstract This thesis summarizes studies which focus on addressing, using both theoretical and experimental methods, fundamental questions about surface phenomena, such as chemical reactions and bonding, related to processes in heterogeneous catalysis. The main focus is on the theoretical approach and this aspect of the results. The included articles are collected into three categories of which the first contains detailed studies of model systems in heterogeneous catalysis. For example, the trimerization of acetylene adsorbed on Cu(110) is measured using vibrational spectroscopy and modeled within the framework of Density Functional Theory (DFT) and quantitative agreement of the reaction barriers is obtained. In the second category, aspects of fuel cell catalysis are discussed. O2 dissociation is rate-limiting for the reduction of oxygen (ORR) under certain conditions and we find that adsorbate-adsorbate interactions are decisive when modeling this reaction step. Oxidation of Pt(111) (Pt is the electrocatalyst), which may alter the overall activity of the catalyst, is found to start via a PtO-like surface oxide while formation of a-PtO2 trilayers precedes bulk oxidation. When considering alternative catalyst materials for the ORR, their stability needs to be investigated in detail under realistic conditions. The Pt/Cu(111) skin alloy offers a promising candidate but segregation of Cu atoms to the surface is induced by O adsorption. -
Surface Models in Heterogeneous Catalysis the Synthesis of Ammonia and the Conversion of Carbon Monoxide
JOURNAL OF CATALYSIS 8, 29-35 (1967) Surface Models in Heterogeneous Catalysis The Synthesis of Ammonia and the Conversion of Carbon Monoxide G. PARRAVANO From the Deparzment qf Chemical and Metallurgical Engineering, University qf Michigan Ann Arbor, Machigan Received November 16, 1966, revised January 16, 1967 The establishment of chemical equilibria between gas and solid catalysts during the synthesis of NH3 and the conversion of CO is considered. Suitable solid-gas equilibrium reactions are discussed. With the correct choice of the rate-controlling step, the equilib- rium surface models are able to reproduce the experimental expressions for the rates of reaction. These models represent a drastic departure from the concept of a fixed, hetero- geneous surface that has been extensively used in the past for the interpretation of the experimental results on the above reactions. The two approaches, however, complement each other and the validity of each one may well be justified under different experimental conditions. Thus, a model may be considered the extension of the other by modification of some of the parameters of the system. Over the past several years many investi- view and it is certainly invalid for relatively gations have been carried out on the catalytic long periods of catalyst operation. It is, synthesis of NH3 and on the conversion of therefore, of interest to consider other CO. The studies have generally been directed possibilities more physically justifiable. toward the understanding of the nature, In this direction it seems particularly properties, and operation of the catalytic important to consider the possibility that surface through the analysis of experimental equilibration reactions between surface and results of reaction rates. -
Final Program
1 General Information SCOPE OF THE CONFERENCE The 11th Joint MMM/Intermag Conference is sponsored jointly by the American Institute of Physics (PCI) and the Magnetics Society of the IEEE, in cooperation with The American Physical Society. Members of the inter- national scientific and engineering communities interested in recent devel- opments in fundamental and applied magnetism are invited to attend the Conference and contribute to its technical sessions. Sessions will include invited and contributed papers, oral and poster presentations and invited symposia. This Conference provides an outstanding opportunity for partici- pants to meet their colleagues and discuss new, advanced and controversial developments. WASHINGTON, DC The 2010 Joint Conference will be held in the nation’s capital. The city wel- comes 15 million visitors each year of which 1.2 million are international. There are more than 100 restaurants located in the downtown area alone, and the city has been called “one of the most exciting restaurant cities on the East Coast” by Travel & Leisure. To obtain an in-depth and current view of what to see and do while you are here, visit the official website at: http://www.washington.org. Here you will find information on how to trav- el to the Marriott Washington Wardman Park from any of the three local air- ports; you can check on the weather in mid-January, and can request a free Visitors Guide prior to making your trip. VISA REQUIREMENTS The US has updated its visa policies to increase security, so it may take you 3-6 months to apply for and receive your visa. -
A Review of the Structural Architecture of Tellurium Oxycompounds
Mineralogical Magazine, May 2016, Vol. 80(3), pp. 415–545 REVIEW OPEN ACCESS A review of the structural architecture of tellurium oxycompounds 1 2,* 3 A. G. CHRISTY ,S.J.MILLS AND A. R. KAMPF 1 Research School of Earth Sciences and Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601, Australia 2 Geosciences, Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia 3 Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA [Received 24 November 2015; Accepted 23 February 2016; Associate Editor: Mark Welch] ABSTRACT Relative to its extremely low abundance in the Earth’s crust, tellurium is the most mineralogically diverse chemical element, with over 160 mineral species known that contain essential Te, many of them with unique crystal structures. We review the crystal structures of 703 tellurium oxysalts for which good refinements exist, including 55 that are known to occur as minerals. The dataset is restricted to compounds where oxygen is the only ligand that is strongly bound to Te, but most of the Periodic Table is represented in the compounds that are reviewed. The dataset contains 375 structures that contain only Te4+ cations and 302 with only Te6+, with 26 of the compounds containing Te in both valence states. Te6+ was almost exclusively in rather regular octahedral coordination by oxygen ligands, with only two instances each of 4- and 5-coordination. Conversely, the lone-pair cation Te4+ displayed irregular coordination, with a broad range of coordination numbers and bond distances. -
Electrochemical Characterisation of Porous Cathodes in the Polymer Electrolyte Fuel Cell
ELECTROCHEMICAL CHARACTERISATION OF POROUS CATHODES IN THE POLYMER ELECTROLYTE FUEL CELL Frédéric Jaouen Doctoral Thesis Department of Chemical Engineering and Technology Applied Electrochemistry Kungl Tekniska Högskolan Stockholm 2003 TRITA-KET R175 ISSN 1104-3466 ISRN KTH/KET/R-175-SE ISBN 91-7283-450-1 ELECTROCHEMICAL CHARACTERISATION OF POROUS CATHODES IN THE POLYMER ELECTROLYTE FUEL CELL Frédéric Jaouen Doctoral Thesis Department of Chemical Engineering and Technology Applied Electrochemistry Kungl Tekniska Högskolan Stockholm 2003 AKADEMISK AVHANDLING som med tillstånd av Kungl Tekniska Högskolan i Stockholm, framlägges till offentlig granskning för avläggande av teknisk doktorsexamen fredagen den 25 april 2003, kl. 10.15 i Kollegiesalen, Valhallavägen 79, Kungl Tekniska Högskolan, Stockholm. Abstract Polymer electrolyte fuel cells (PEFC) convert chemical energy into electrical energy with higher efficiency than internal combustion engines. They are particularly suited for transportation applications or portable devices owing to their high power density and low operating temperature. The latter is however detrimental to the kinetics of electrochemical reactions and in particular to the reduction of oxygen at the cathode. The latter reaction requires enhancing by the very best catalyst, today platinum. Even so, the cathode is responsible for the main loss of voltage in the cell. Moreover, the scarce and expensive nature of platinum craves the optimisation of its use. The purpose of this thesis was to better understand the functioning of the porous cathode in the PEFC. This was achieved by developing physical models to predict the response of the cathode to steady-state polarisation, current interruption (CI) and electrochemical impedance spectroscopy (EIS), and by comparing these results to experimental ones. -
1 Electrochemical Kinetics of Corrosion and Passivity the Basis
Electrochemical Kinetics of Corrosion and Passivity The basis of a rate expression for an electrochemical process is Faraday’s law: Ita m = nF Where m is the mass reacted, I is the measured current in ampere, t is the time, a is the atomic weight, n the number of electrons transferred and F is the Faraday constant (96500 Cmol-1). Dividing Faraday’s law by the surface area A and the time t leads to an expression for the corrosion rate r: m ia r = = tA nF With the current density i defined as i = I/A. Exchange current density: We consider the reaction for the oxidation/reduction of hydrogen: rf + - 2H + 2e H2 rr 0 + This reaction is in the equilibrium state at the standard half cell potential e (H /H2). This means that the forward reaction rate rf and the reverse reaction rate rr have the same magnitude. This can be written as: i a r = r = 0 f r nF In this case is i0 the exchange current density equivalent to the reversible rate at equilibrium. In other words, while the standard half cell potential e0 is the universal thermodynamic parameter, i0 is the fundamental kinetic parameter of an electrochemical reaction. The exchange current density cannot be calculated. It has to be measured for each system. The following figure shows that the exchange current density for the hydrogen reaction depends strongly on the electrode material, whereas the standard half cell potential remains the same. 1 Electrochemical Polarization: Polarization η is the change in the standard half cell potential e caused by a net surface reaction rate. -
An Investigation Into Aqueous Titanium
An Investigation into Aqueous Titanium Speciation Utilising Electrochemical Methods for the Purpose of Implementation into the Sulfate Process for Titanium Dioxide Manufacture Samala Shepherd, BSc. (Hons) Masters of Philosophy in Chemistry University of Newcastle March, 2013 STATEMENT OF ORIGINALITY This thesis contains no material which has been accepted for the award of any other degree or diploma in any university or other tertiary institution and, to the best of my knowledge and belief, contains no material previously published or written by another person, except where due reference has been made in the text. I give consent to this copy of my thesis, when deposited in the University Library**, being made available for loan and photocopying subject to the provisions of the Copyright Act 1968. **Unless an Embargo has been approved for a determined period. Samala L. Shepherd i Acknowledgements There are many people who have helped me and contributed to my work in a number of ways and I’d like to thank them. I’d like to thank BHP Billiton Newcastle Technology Centre for making this project possible. The ARC for support and funding. Dr. Scott Donne for the vast knowledge he provided me with and the friendship and support. Thank you to Carolyn Freeburn, Vicki Thompson, and Stephen Hopkins for the ‘store/equipment room’ when I was in need. Thank you to Dianna Brennan for keeping me supplied. Michael Fitzgerald for his continued support. Last but not least a big thanks to my family, they are stuck with me but bare the burden with smiles and support and I thank them greatly. -
Catalytic Oxidation of NO to NO2 for Nitric Acid Production Over a Pt
1 Catalytic oxidation of NO to NO2 for nitric acid production over a Pt/Al2O3 catalyst Ata ul Rauf Salmana, Bjørn Christian Engerb, Xavier Auvraya c, Rune Lødengb, Mohan Menond, David Wallerd, Magnus Rønninga* a Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), Sem Sælands vei 4, NO-7491 Trondheim, Norway. b SINTEF Industry, Kinetic and Catalysis group, P.O. Box 4760 Torgarden, NO-7465 Trondheim, Norway. c Current address: Competence Centre for Catalysis, Chemical Engineering, Chalmers University of Technology, S-412 96 Gothenburg, Sweden d YARA Technology Center, Herøya Forskningspark, Bygg 92, Hydrovegen 67, NO-3936 Porsgrunn, Norway. * Corresponding author. Tel.: +47 73594121. E-mail address: [email protected] (M. Rønning). 2 Abstract The oxidation of nitric oxide (NO) to nitrogen dioxide (NO2) is a key step both in NOx abatement technologies as well as in the Ostwald process for nitric acid production. A 1 wt.% Pt/Al2O3 catalyst was used to study oxidation of nitric oxide at two different concentrations of NO; 400 ppm NO (representative of engine exhaust treatment) and 10% NO (nitric acid plant). The catalyst was characterised using N2 adsorption and CO chemisorption. The effect of temperature and feed concentration on catalytic activity was investigated. For a feed comprising of 10% NO and 6% O2, Pt/Al2O3 exhibits significant catalytic activity above o 300 C. Addition of 15% H2O in the feed had an insignificant effect on activity of the catalyst. We report for the first time the kinetics for oxidation of NO to NO2 under nitric acid plant conditions. An apparent activation energy of 33 kJ/mol was observed. -
Cathodic Hydrogen Evolution Reaction on Gold Catalyzed by Proton-Carriers
Int. J. Electrochem. Sci., 9 (2014) 4465 - 4477 International Journal of ELECTROCHEMICAL SCIENCE www.electrochemsci.org Cathodic Hydrogen Evolution Reaction on Gold Catalyzed by Proton-Carriers Raluca Creţu, Andrea Kellenberger, Mihai Medeleanu, Nicolae Vaszilcsin* Universitatea Politehnica Timişoara, Faculty of Industrial Chemistry and Environmental Engineering, 300006 Piata Victoriei 2, Timişoara, Romania *E-mail: [email protected] Received: 6 March 2014 / Accepted: 3 April 2014 / Published: 19 May 2014 Several amines with aromatic and aliphatic substituents have been investigated as catalysts in the solution for the hydrogen evolution reaction, based on their ability to increase the concentration of protons in the electric double layer at the interface, by transporting protons from the bulk solution to the cathode surface. The highest electrocatalytic activity, expressed by the activation energy for hydrogen evolution reaction has been obtained for methylamine, 4-chloroaniline and aniline. In this series, the catalytic activity is primarily influenced by the molecular coverage area, which determines the number of protonated molecules that can adsorb on the cathode surface. The second factor that affects catalytic activity is the magnitude of the dipole moment, which determines a preferential orientation of the protonated molecule at the interface. As a consequence, methylamine shows the highest catalytic activity due to its low coverage area and 4-chloroaniline has a stronger effect than aniline due to its larger dipole moment induced by the electron-withdrawing inductive effect of chlorine. A mechanism for hydrogen evolution reaction in the presence of amines has been proposed, where both hydronium and ammonium ions are involved in the charge transfer process. Keywords: Hydrogen evolution reaction, proton carriers, Tafel plots, Arrhenius plots, Charge transfer coefficient 1. -
Mechanism of the Chlorine Evolution on a Ruthenium Oxide/Titanium Oxide Electrode and on a Ruthenium Electrode
Mechanism of the chlorine evolution on a ruthenium oxide/titanium oxide electrode and on a ruthenium electrode Citation for published version (APA): Janssen, L. J. J., Starmans, L. M. C., Visser, J. G., & Barendrecht, E. (1977). Mechanism of the chlorine evolution on a ruthenium oxide/titanium oxide electrode and on a ruthenium electrode. Electrochimica Acta, 22(10), 1093-1100. https://doi.org/10.1016/0013-4686(77)80045-5 DOI: 10.1016/0013-4686(77)80045-5 Document status and date: Published: 01/01/1977 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. -
Preparation and Spectral Properties of Oxomolybdenum(V) Complexes. Harry Edmond Pence II Louisiana State University and Agricultural & Mechanical College
Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1968 Preparation and Spectral Properties of Oxomolybdenum(v) Complexes. Harry Edmond Pence II Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Pence, Harry Edmond II, "Preparation and Spectral Properties of Oxomolybdenum(v) Complexes." (1968). LSU Historical Dissertations and Theses. 1411. https://digitalcommons.lsu.edu/gradschool_disstheses/1411 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 Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. This dissertation has been microfilmed exactly as received 68-10,753 PENCE n , Harry Edmond, 1937- PREPARATION AND SPECTRAL PROPERTIES OF OXOMOLYBDENUM(V) COMPLEXES. Louisiana State University and Agricultural and Mechanical College, Ph.D., 1968 Chemistry, inorganic University Microfilms, Inc., Ann Arbor, Michigan PREPARATION AND SPECTRAL PROPERTIES OF OXOMOLYBDENUM ( V) COMPLEXES 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 Harry Edmond Pence II B.S., Bethany College, Bethany, W.Va., 1958 M.S., West Virginia University, Morgantown, W.Va., 1962 February, 1968 To Ginn ACKNOWLEDGMENTS The final creation of this dissertation has been assisted by many different individuals and it is appropriate to attempt to indicate some of these contributors and offer the sincere thanks of the author,, The most important component of this assistance has been the continual encouragement offered by parents and family.