Sökning: "O2-dissociation"

Hittade 5 avhandlingar innehållade ordet O2-dissociation.

  1. 1. On the Character of Active Sites in Copper Exchanged Zeolites during NH3-SCR

    Författare :Lin Chen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cu-SSZ-13; SSIE; O2-dissociation; Al-distribution; NH3-SCR; Chabazite; O2-activation;

    Sammanfattning : Nitrogen oxides (NOx) are formed during combustion in diesel engines and one current approach to reduce NOx to N2 is selective catalytic reduction with NH3 as reducing agent (NH3-SCR). To acquire both high activity and selectivity, the active site is often atomically dispersed metal atom, so-called single-site catalysts. LÄS MER

  3. 2. Electronic structure and spectroscopy calculations in fuel cell catalysis

    Författare :Henrik Öberg; Lars G.M. Pettersson; Göran Lindbergh; Stockholms universitet; []
    Nyckelord :Chemical Physics; kemisk fysik;

    Sammanfattning : This thesis presents joint experimental and theoretical studies of surface phenomena at an electronic structure level in proton exchange membrane fuel cells (PEM-FC's). The fuel cell activity can be related to the oxygen reduction taking place at the cathodic surface through the oxygen reduction reaction (ORR). LÄS MER

  4. 3. Surface reactions and chemical bonding in heterogeneous catalysis

    Författare :Henrik Öberg; Lars G. M. Pettersson; Philippe Sautet; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; kemisk fysik; Chemical Physics;

    Sammanfattning : This thesis summarizes studies which focus on addressing, using both theoretical and experimental methods, fundamental questions about surface phenomena, such as chemical reactions and bonding, related to processes in heterogeneous catalysis. The main focus is on the theoretical approach and this aspect of the results. LÄS MER

  5. 4. On the reaction mechanism for selective catalytic reduction of NOx by NH3 over Cu-zeolites

    Författare :Lin Chen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; DFT; O2-activation; Cu-SSZ-13; NH3-SCR; Cu-CHA; Al-distribution;

    Sammanfattning : Nitrogen oxides (NOx) are major pollutants from combustion processes, being corrosive and hazardous to human health. The main technology for exhaust aftertreatment of NOx emitted from diesel engines is selective catalytic reduction with ammonia as reducing agent (NH3-SCR). LÄS MER

  7. 5. Density Functional Theory Studies of Small Supported Gold Clusters and Related Questions : What a Difference an Atom Makes

    Författare :Martin Amft; Natalia Skorodumova; Olle Eriksson; Hannu Häkkinen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gold clusters; CO oxidation; graphene; spin-orbit coupling; van der Waals interactions; thermally excited vibrations; 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 : During the last decades the specific manipulation of matter on the (sub-) nanometer scale, also known as nanoscience, became possible by technologies such as the scanning tunneling microscope. Nanocatalysts, i.e. catalytic active structures of up to a few nanometers in size, belong to this rather new class of materials. LÄS MER