Sökning: "Silver Alumina"

Visar resultat 6 - 10 av 17 avhandlingar innehållade orden Silver Alumina.

  1. 6. Lean NOx reduction over silver-alumina catalysts - Aspects on synthesis, structure and activity

    Författare :Hannes Kannisto; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; freeze-drying; HC-SCR; DRIFTS.; aromatic hydrocarbons; silver-alumina; Lean NOx reduction; selective catalytic reduction; sol-gel; characterization; catalyst preparation; kinetic modeling;

    Sammanfattning : The aim of this thesis is to increase the understanding of how to design highly active silver-alumina catalysts for selective catalytic reduction of NOx with hydrocarbons (HC-SCR) in oxygen excess at low temperatures (150-250 °C). Silver-alumina catalysts have been prepared using different methods, including a new unique preparation method developed during the thesis project. LÄS MER

  2. 7. Studies of hydrocarbon-assisted selective catalytic reduction of nitrogen oxides - DME as reductant and reaction mechanism over silver/alumina

    Författare :Stefanie Tamm; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ZSM-5; NCO; HC-SCR; Dimethyl ether; reaction mechanism; silver alumina;

    Sammanfattning : Increasing amounts of carbon dioxide are attaining worldwide growing attention as one probable cause for global warming. Together with the expected peak in oil production and an increasing oil demand, this results in a greater interest in more fuel effective lean burn engines (i.e. operation with excess oxygen). LÄS MER

  3. 8. Experimental and kinetic studies of H2 effect on lean exhaust aftertreatment processes: HC-SCR and DOC

    Författare :Muhammad Mufti Azis; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HC-SCR; NO oxidation.; Hydrogen effect; NOx reduction; Kinetic modeling; Silver Alumina; DOC; Platinum Alumina;

    Sammanfattning : With a growing concern to lower greenhouse gas emissions from road transportation, lean burn and diesel engines will keep playing an important role in the future. Development of a highly efficient and durable process to reduce NOx to N2 becomes a challenging issue especially in the presence of ample O2 concentration as in lean burn exhaust. LÄS MER

  4. 9. Surface Studies of Model Systems relevant for Pd and Ag Catalysts

    Författare :Natalia Martin; Synkrotronljusfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High Pressure X-ray Photoelectron Spectroscopy; X-ray Photoelectron Spectroscopy; alumina; Ag; NiAl; Pd; catalysis; model system; Surface X-ray Diffraction; Low Energy Electron Diffraction; Scanning Tunneling Microscopy; Fysicumarkivet A:2014:Martin;

    Sammanfattning : This PhD thesis reports on investigations of the atomic scale structure of model catalysts relevant for the catalytic oxidation of CO and methane over Pd, and NOx reduction over silver-alumina, important reactions in automotive catalysts. By using complementary experimental techniques such as X-ray Photoelectron Spectroscopy, High Pressure X-ray Photoelectron Spectroscopy, Surface X-ray Diffraction, Low Energy Electron Diffraction, Infrared Spectroscopy, and Scanning Tunneling Microscopy, combined with theoretical calculations, the work presented in this thesis aims at an atomistic characterization of the active sites for silver-alumina and Pd model catalysts which may help to the design of new and improved catalysts. LÄS MER

  5. 10. Selective Catalytic Reduction of NOx over Alumina-Supported Silver and Indium During Lean Operation

    Författare :Linda Ström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Catalytic emission control for vehicles was first applied in the 1970’s. The first such catalysts were designed to oxidize unburned hydrocarbons (HC) and carbon monoxide (CO). LÄS MER