atom resolved surface reactions. nanocatalysis

[...]... caesium atoms impinging on the surface were adsorbed, indicating that they sought vacant sites on the surface and were mobile Langmuir made the point in his lecture that the ‘‘lifetime t of an atom at the surface is not independent of the presence of other atoms, being given by t ¼ t0(1 – y) The shortening of the lifetime t as y approaches unity is the result of strong repulsive forces between pairs of atoms... fractal surfaces led to an interest in surface phenomena and, after graduating with double honours in 1986, he moved to Cardiff to study reactions at surfaces with surface- sensitive spectroscopy After being awarded a PhD, he was appointed to a lectureship in the Department of Chemistry at Cardiff His main research interests are studying reaction mechanisms at surfaces primarily through the use of surface. .. seen to hold at the atom resolved level Tracey and Blakely drew attention to the limitations of LEED (at that time), which, although providing evidence on the symmetry of surface structures, did not define either the surface coverage or the precise atomic arrangement, an aspect that was pursued subsequently with much vigour 1.12 1972: A Discussion on the Physics and Chemistry of Surfaces, London14 This... 21 26 27 30 31 35 37 38 40 42 43 43 44 46 48 Dynamics of Surface Reactions and Oxygen Chemisorption 4.1 Introduction 4.2 Surface Reconstruction and ‘‘Oxide’’ Formation 4.3 Oxygen States at Metal Surfaces 4.4 Control of Oxygen States by Coadsorbates 4.5 Adsorbate Interactions, Mobility and Residence Times 4.6 Atom- tracking STM 4.7 Hot Oxygen Adatoms: How are they Formed? 4.8 Summary References Further... attention to the problems associated with metal surfaces prepared by various methods Mobility of surface atoms was anticipated to occur when the temperature of the solid was above 0.3Tm, whereas mobility of the bulk atoms occurred above 0.5Tm (the Tammann temperature), where Tm is the melting point in kelvin of the solid In contrast to what we shall discuss later, surface mobility was considered to be a phenomenon... physics of surfaces, we draw attention to two papers, the first by Becker and the second by H.A Taylor It is clear that Becker was greatly influenced by the development of the field emission microscope and what it revealed about ‘‘foreign atoms’’ adsorbed on metal surfaces and how the work function varies from one crystal face to another, and that ‘‘in adsorption the arrangement of the surface metal atoms... (Suhrmann) and flash-filament, later renamed temperatureprogrammed desorption (Ehrlich) Surface cleanliness of metal surfaces had become a fundamental issue and a pointer to the development of what became referred to as the surface science approach to catalysis 6 Chapter 1 1.8 1963: Conference on Clean Surfaces with Supplement: Surface Phenomena in Semiconductors, New York10 This was an outstanding meeting... 150 151 152 153 155 Nanoparticles and Chemical Reactivity 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 Introduction Controlling Cluster Size on Surfaces Alloy Ensembles Nanoclusters at Oxide Surfaces Oxidation and Polymerisation at Pd Atoms Deposited on MgO Surfaces Clusters in Nanocatalysis Molybdenum Sulfide Nanoclusters and Catalytic Hydrodesulfurisation Reaction Pathways Nanoparticle Geometry at Oxide-supported... Pt(110)–(1 Â 2) Surface by Carbon Monoxide 7.4 Adsorption-induced Step Formation 7.5 Gold Particles at FeO(111) 7.6 Hydrogen–Deuterium Exchange and Surface Poisoning 7.7 Summary References Further Reading 7.3 Chapter 8 132 133 134 134 Molecular and Dissociated States of Molecules: Biphasic Systems 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 Introduction Nitric Oxide Nitrogen Adatoms: Surface Structure... understanding of surface catalysis The paper by Volmer considers experimental evidence for the migration of molecules at surfaces from the viewpoint of crystal growth He emphasises the need to search for experimental evidence for ‘‘two-dimensional mobility’’ and discusses Estermann’s data for silver on quartz and benzophenone on mica surfaces 4 Chapter 1 What was evident in 1950 was that very few surface- sensitive . Diffraction TPD Temperature-programmed Desorption TPR Temperature-programmed Reaction UHV Ultra-high Vacuum UPS Ultraviolet Photoelectron Spectroscopy XPS X-ray Photoelectron Spectroscopy XRD X-ray. X-ray Absorption Fine Structure PIS Penning Ionisation Spectroscopy RAIRS Reflection Absorption Infrared Spectroscopy SEM Scanning Electron Microscopy SEXAFS Surface Extended X-ray Absorption Fine. Discussion, Liverpool 3 1.6 1954: Properties of Surfaces 4 1.7 1957: Advances in Catalysis; International Congress on Catalysis, Philadelphia 5 1.8 1963: Conference on Clean Surfaces with Supple- ment: Surface