Search for dissertations about: "OXIDE SURFACES"

Showing result 21 - 25 of 242 swedish dissertations containing the words OXIDE SURFACES.

  1. 21. Adsorption, desorption, and redox reactions at iron oxide nanoparticle surfaces

    Author : Lelde Krumina; MEMEG; []
    Keywords : Ferrihydrite; Goethite; Secondary metabolites; Reductive dissolution; Catalytic oxidation; hydroxyl radicals; Fenton reaction; SOM decomposition;

    Abstract : Iron oxide nanoparticles are involved in several important biogeochemical processes. The interfaces between aqueous solutions and iron oxide nanoparticle surfaces are found everywhere in nature, and the chemical and microbial processes occurring at these complex interfaces control e.g. nutrient and contaminant availability and transport. READ MORE

  2. 22. Key Aspects of Sintering Powder Metallurgy Steel Prealloyed with Chromium and Manganese

    Author : Ola Bergman; Chalmers University of Technology; []
    Keywords : Manganese; Prealloyed; Sintering; Mechanical properties; Chromium; Spinel oxide; Powder metallurgy; PM steel; Oxide reduction; Residual oxides; Atmosphere;

    Abstract : The powder metallurgy (PM) process is a cost efficient near net-shape technology suitable for sustainable manufacturing of structural steel components. A drawback with the PM technology is the difficulty to use oxidation sensitive alloying elements, such as Cr and Mn. READ MORE

  3. 23. The effect of surface steps and oxides on the catalytic activity on model Pd and Rh catalysts

    Author : Chu Zhang; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Surface X-ray diffraction SXRD ; X-ray photonelectron spectroscopy; Catalytic activity; Oxide; Single Crystal surface; surface structure; vicinal surface; CO oxidation; stepped surface; Fysicumarkivet A:2018:Zhang;

    Abstract : A catalyst is a substance that can speed up the rate of a chemical reaction without itself being consumed. Catalysts are crucial for chemical production industries, where about 90% of all chemicals are produced using catalysts. READ MORE

  4. 24. Metal-Organic Complexes at Surfaces

    Author : Cristina Isvoranu; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; x-ray absorption spectroscopy; x-ray photoelectron spectroscopy; bi-isonicotinic acid; oxalic acid; spin change; gas adsorption; metal-organic complex; iron phthalocyanine; scanning tunneling spectroscopy; resonant photoemission spectroscopy;

    Abstract : The adsorption of different metal-organic complexes at surfaces was investigated by spectroscopic techniques (x-ray photoemission spectroscopy, x-ray absorption spectroscopy, resonant photoemission spectroscopy) and by scanning tunnelling microscopy. The investigation methods are able to provide atomic scale information on the studied systems, which moreover originates from the top-most atomic layers in a sample, meaning that they are surface sensitive techniques. READ MORE

  5. 25. Structure, Morphology, and Catalytic Properties of CuOx/CeO2 Model Catalysts

    Author : Björn Skårman; Centrum för analys och syntes; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Synchrotron radiation; High-energy Diffraction; X-ray Absorption Fine Structure Spectroscopy.; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Chemistry; Kemi; Material technology; Materiallära; materialteknik; X-ray photoelectron spectroscopy; Atomic force microscopy; Gatan Image Filter GIF ; Energy-filtered TEM; High-resolution electron microscopy; Inert gas condensation IGC ; rf Magnetron sputtering; Thermal activation; Batch reactor; Carbon monoxide oxidation; Surface sensitivity; Catalytic anisotropy; Growth; Nucleation; Topography; Roughness; Core-shell structures; Morphology; Nanostructured; Nanocomposite; Nanoparticles; Surface structure; Polycrystalline surfaces; Thin films; Copper oxide; Cerium dioxide CeO2 ; Ceria;

    Abstract : Cerium dioxide, or ceria, is a chemically stable oxygen ion conducting material with a capacity to store and release oxygen, and is therefore extensively used in combustion catalysts. The Cu-Ce-O system has been identified as one of the most active catalysts for the combustion of carbon monoxide. READ MORE