Sökning: "Ir 111"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden Ir 111.

  1. 1. Probing Atomic Scale Structure and Catalytic Properties of Cobalt Oxide Model Catalysts

    Författare :Alif Arman; Synkrotronljusfysik; []
    Nyckelord :catalysis; model systems; Co3O4 111 ; Co3O4 100 ; CoO 111 ; X-ray photoelectron spectroscopy; Scanning tunneling microscopy; Fysicumarkivet A:2017:Arman;

    Sammanfattning : Cobalt oxides are known to be active catalysts for a number of chemical reactions, but very little is known about the atomic scale processesresponsible for the activity. The research presented in this thesis is focused on obtaining an atomic scale understanding of the chemistry of wellcharacterizedcobalt oxide model catalyst surfaces consisting of pristine and defective CoO and Co3O4 thin films with the (111) and (100)terminations supported by Ag(100), Ir(100), and Au(111) single crystal surfaces. LÄS MER

  2. 2. Above and Below Graphene: Nanoparticle Chemistry and Interface Reactions

    Författare :Elin Grånäs; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Graphene; Scanning tunneling microscopy; X-ray photoelectron spectroscopy; Adsorption; Nanoparticles; Ir 111 ; Surface science;

    Sammanfattning : The work presented in this dissertation addresses two main topics: (i) graphene supported nanoparticles and their stability upon gas adsorption, and (ii) intercalation of different molecules under graphene and their reactions under graphene. From an interplay of X-ray photoelectron spectroscopy, scanning tunneling microscopy, low energy electron diffraction, and density functional theory an atomic scale understanding of both the nanoparticles and the intercalated structures is obtained. LÄS MER

  3. 3. Controlling Electronic and Geometrical Structure of Honeycomb-Lattice Materials Supported on Metal Substrates : Graphene and Hexagonal Boron Nitride

    Författare :Nikolay Vinogradov; Nils Mårtensson; Karsten Horn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; graphene; h-BN; electronic structure; adsorption; doping; nano-templates; PES; NEXAFS; LEEM; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The present thesis is focused on various methods of controlling electronic and geometrical structure of two-dimensional overlayers adsorbed on metal surfaces exemplified by graphene and hexagonal boron nitride (h-BN) grown on transition metal (TM) substrates. Combining synchrotron-radiation-based spectroscopic and various microscopic techniques with in situ sample preparation, we are able to trace the evolution of overlayer electronic and geometrical properties in overlayer/substrate systems, as well as changes of interfacial interaction in the latter. LÄS MER

  4. 4. Characterization and Functionalization of 2D Overlayers Adsorbed on Transition Metals

    Författare :May Ling Ng; Nils Mårtensson; Alexei Preobrajenski; Anne Borg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; h-BN; graphene; transition metals; nanomesh; functionalization; PES; NEXAFS; STM; LEED; Condensed matter physics; Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Two-dimensional layered materials, namely monolayer hexagonal boron nitride and graphene were grown by CVD on various transition metals. The physical and chemical properties of these systems were characterized systematically using synchrotron-based spectroscopic techniques, scanning tunneling microscopy and low energy electron diffraction. LÄS MER

  5. 5. Synchrotron-based In Situ Electron Spectroscopy Applied to Oxide Formation and Catalysis

    Författare :Niclas Johansson; Synkrotronljusfysik; []
    Nyckelord :CO oxidation; Sonogashira cross-coupling; trilayer FeO; vicinal FeO; Mn III -salen; APXPS; XAS; Fysicumarkivet A:2017:Johansson;

    Sammanfattning : In this thesis, in situ ambient pressure X-ray photoelectron spectroscopy has been used to address chemical reactions on surfaces. The presented work aims at the investigation of the relation between pressure and adsorbate surface structures during catalytic reactions. LÄS MER