Sökning: "Pd Rh"

Visar resultat 16 - 20 av 27 avhandlingar innehållade orden Pd Rh.

  1. 16. Calculations of Clean and Adsorbate Covered Metal Surfaces and their Core-Level Photoemission Spectra

    Författare :Martin Birgersson; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chemical shifts; density functional theory; Condensed matter:electronic structure; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; Atomic and molecular physics; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; core-level photoemission; single crystal surfaces; Atom- och molekylärfysik; Fysicumarkivet A:2002:Birgersson; core-hole degeneracies; metal surfaces; adsorption; molecular vibrations;

    Sammanfattning : The present thesis is concerned with the theoretical study of x-ray photoemission spectra from clean and adsorbate-covered metal surfaces. The main tool is ab initio density functional (DFT) total energy calculations. LÄS MER

  2. 17. Preparation and characterisation of perovskite and noble metal promoted oxide based catalysts

    Författare :Leif Dahl; Ragnar Larsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; oorganisk kemi; Inorganic Chemistry;

    Sammanfattning : This work concerns efforts to improve or replace noble-metal based catalysts used for car exhaust purification.Various oxide based catalysts have been prepared by impregnating washcoats such as (-Al2O3 and SiO2 with appropriate metal ions, and assemblies calcinated at elevated temperatures have been tested for catalytic activity in the oxidation of CO and C3H6 and reduction of NO. LÄS MER

  3. 18. Deactivation of commercial three-way catalysts: effect of the thermal ageing

    Författare :Anna Fathali; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BET; methane production from E85; NOx reduction by methane; Rhodium; TWC; OSC; Automotive exhaust control; Palladium; Aging;

    Sammanfattning : This licentiate thesis is a summary of my study on thermal deactivated commercial threeway catalysts (TWCs). The experiments were performed using gasoline and a E85 fuelmixture of 85 vol.% ethanol and 15 vol.% gasoline. LÄS MER

  4. 19. Development of a regeneration procedure for commercial automotive three-wy catalysts

    Författare :Henrik Birgersson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; deactivation; fouling; sintering; poisoning; palladium; rhodium; regeneration; dispersion; thermal gas treatment; oxy-chlorine; TWC; automotive catalyst; Chemical process equipment; Kemisk apparatteknik;

    Sammanfattning : Car exhaust catalysts were introduced in the early 1980’s, to limit the release of pollutants such as hydrocarbons, carbon monoxides and nitrogen oxides. These catalysts contain noble metals such as palladium (Pd), platinum (Pt) and rhodium (Rh) and are able to simultaneously abate all three of the above-mentioned pollutants, hence the name three-way catalyst (TWC). LÄS MER

  5. 20. Aerosol Metal Nanoparticles and their Role in Particle-Assisted Growth of III–V Nanowires

    Författare :Robert Hallberg; NanoLund: Centre for Nanoscience; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aerosol formation; III–V semiconductor materials; catalyst particles; Palladium nanoparticles; Gold nanoparticles; Spark discharge generation; MOVPE; MOCVD; Transmission electron microscopy TEM ; Phase stability; Nanoparticle deposition; Nanoparticle generation; nanoparticles characterization; Nanowire NW ; Nanowire growth;

    Sammanfattning : Semiconductor nanowires have properties that make them potentially useful for applications in future electronic, photovoltaic, and optoelectronic devices. A powerful nanowire fabrication technique is the use of a nanoparticle as a preferential nucleation site, from which a nanowire grows. LÄS MER