Sökning: "catalytic deactivation"

Visar resultat 6 - 10 av 74 avhandlingar innehållade orden catalytic deactivation.

1. 6. Deactivation of commercial three-way catalysts: Experimental and theoretical studies

   Författare :Anna Fathali; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; car exhaust; three-way catalyst TWC ; alumina; fuel-cut; palladium; ; hydrocarbon cracking; ceria; deactivation; oxygen storage capacity OSC ; rhodium; zirconia; sintering; monolith catalyst; catalysis;

   Sammanfattning : This PhD thesis is a summary of my work with thermal deactivated commercial three way catalysts (TWCs). An examination of catalytic properties, before and after accelerated aging was performed, such as light-off temperature, specific surface area (BET), noble metal dispersion and oxygen storage capacity was performed. LÄS MER

3. 7. Metal-exchanged zeolites for NH3-SCR applications - Activity and Deactivation studies

   Författare :Soran Shwan; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; modeling; NOX.; Hydrothermal; Chemical; Kinetic; Copper; Deactivation; Iron; Zeolite; Nitrogen oxides; NH3; Ammonia; Catalyst; NSR; Emissions; Poisoning; Ageing; NH3-SCR;

   Sammanfattning : Emissions of nitrogen oxides (NOX) formed during the burning process in internal combustion engines is a major contributor to global air pollutions. One effective way to reduce NOX in lean environments, i.e. oxygen excess is selective catalytic reduction with ammonia (NH3-SCR). LÄS MER

4. 8. Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation

   Författare :Javier Barrientos; Magali Boutonnet; Claude Mirodatos; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cobalt; nickel; Fischer-Tropsch synthesis; methanation; deactivation; carbonyl; sintering; carbon fomation. sulfur; poisoning; Chemical Engineering; Kemiteknik;

   Sammanfattning :             A potential route for converting different carbon sources (coal, natural gas and biomass) into synthetic fuels is the transformation of these raw materials into synthesis gas (CO and H2), followed by a catalytic step which converts this gas into the desired fuels. The present thesis has focused on two catalytic steps: Fischer-Tropsch synthesis (FTS) and methanation. LÄS MER

5. 9. Unveiling Catalytic Species in Suspension/Solution-Based Reactions by In Situ X-Ray Absorption Spectroscopy : Evolution of Palladium and Ruthenium Species

   Författare :Ning Yuan; Xiaodong Zou; Ingmar Persson; Gopinathan Sankar; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palladium and ruthenium species; Catalysts; Suspension and solution; In situ X-ray absorption spectroscopy; Activation; Deactivation; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : The palladium (Pd) and ruthenium (Ru) species in several attractive catalysts have been probed using X-ray absorption spectroscopy (XAS). The study of catalyst evolution in suspension- and solution-based reactions was the primary aim. It was achieved by performing in situ XAS experiments on Pd and Ru over the course of the reactions. LÄS MER

7. 10. Catalytic Upgrading of Waste Oils to Advanced Biofuels – Deactivation and Kinetic Modelling Study

   Författare :Prakhar Arora; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Stearic acid; TEM; Advanced biofuels; NiMo; Catalytic HDO; MoS2; Kinetic modelling; Oleic acid; Hydrodeoxygenation;

   Sammanfattning : The demand for liquid hydrocarbons as transportation fuels is enormous and ever growing. Advanced biofuels is one of the promising solutions to keep pace with the global transition to cleaner energy by reducing greenhouse gas emissions from the transport sector. LÄS MER