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Visar resultat 1 - 5 av 500 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Computational Studies of Chemical Interactions: Molecules, Surfaces and Copper Corrosion

    Författare :Joakim Halldin Stenlid; Tore Brinck; Thomas Bligaard; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; computational chemistry; density functional theory; chemical interactions; reactivity descriptors; copper corrosion; surface and materials science; nucleophilic substitution reactions; heterogeneous catalysis; transition metal oxides; nanotechnology; beräkningskemi; täthetsfunktionalteori; kemiska interaktioner; reaktivitetsdeskriptorer; kopparkorrosion; yt- och materialvetenskap; nukleofila substitutionsreaktioner; heterogen katalys; överångsmetalloxider; nanoteknologi; Kemi; Chemistry;

    Sammanfattning : The chemical bond – a corner stone in science and a prerequisite for life – is the focus of this thesis. Fundamental and applied aspects of chemical bonding are covered including the development of new computational methods for the characterization and rationalization of chemical interactions. LÄS MER

  3. 2. Influence of total pressure on complete oxidation of methane over Pd/Al2O3 catalysts

    Författare :Carl-Robert Florén; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Pd Al2O3; methane oxidation; multiscale flow-reactor model; total pressure;

    Sammanfattning : Natural gas and biogas, which have methane as their main component, are interesting choices of fuel to reduce the anthropogenic emissions of greenhouse gases. However, as methane is a greenhouse gas, uncombusted methane should be removed from the combustion gases. Emission control catalysts can preferably be used to completely oxidise methane. LÄS MER

  4. 3. Titanium oxide nanoparticle production using high power pulsed plasmas

    Författare :Rickard Gunnarsson; Ulf Helmersson; Grzegorz Greczynski; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This thesis covers fundamental aspects of process control when growing titanium oxide nanoparticles in a reactive sputtering process. It covers the influence of oxygen containing gas on the oxidation state of the cathode from which the growth material is ejected, as well as its influence on the particles oxidation state and their nucleation. LÄS MER

  5. 4. Deactivation of SCR catalysts - Impact of sulfur and the use of biofuels

    Författare :Johanna Englund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Cu-SSZ-13; Cu-CHA; Catalyst deactivation; Activity test; DeNOx; Sulfur; NOx reduction; NH3-SCR; FAME; Emission control; HVO; Vanadia; Biofuel;

    Sammanfattning : In a near future, limits on CO2 emissions from vehicles will be introduced, which requires development of more fuel-efficient engines and most likely a transition towards the use of more biofuels. With the implementation of biofuels several issues could arise, one being the lack of fuel standards for these new type of fuels, leading to higher concentrations of catalyst poisons compared to conventional fossil fuels. LÄS MER

  7. 5. Operando X-ray Absorption Spectroscopy Studies of Methane Oxidation Catalysts

    Författare :Johan Nilsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; operando spectroscopy; XAS; palladium; heterogeneous catalysis; methane oxidation; XAFS;

    Sammanfattning : Operando spectroscopy is an experimental method in catalysis that combines measurements of catalytic activity and selectivity with simultaneous in situ spectroscopic characterization of the catalyst. Since the structure and composition of the catalyst are probed under reaction conditions, the method can provide valuable information to elucidate the mechanism of the studied reaction. LÄS MER