Search for dissertations about: "CHA"

Showing result 16 - 20 of 32 swedish dissertations containing the word CHA.

2. 16. Deactivation of after-treatment catalysts for bio-fuelled engines

   Author : Johanna Englund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Environmental catalysis; Cu-CHA; Vanadium; Supported palladium platinum; Biodiesel; Biogas; NOx reduction; Methane oxidation; Sustainable transports;

   Abstract : To decrease the emissions of anthropogenic CO2 from vehicles one option is to increase the utilization of biobased fuels. However, there are challenges with this transition, one being the mitigation of emissions of the potent greenhouse gas methane, which is the main constituent of biogas. READ MORE

4. 17. Reactions of Model and Anticancer Active Platinum(IV/II) Complexes - A Kinetic and Mechanistic Study

   Author : Kelemu Lemma; Kemiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Model Pt II complexes; Anticancer active Pt IV compounds; Cisplatin; Rescue agents; L-Ascorbic acid; Thiol; Substitution; Kinetics and mechanism; Electron transfer; Inorganic chemistry; Oorganisk kemi;

   Abstract : In this thesis reductions of model and anticancer active Pt(IV) complexes with thiols and ascorbic acid and substitution reactions of cisplatin and model Pt(II) complexes with S-donor nucleophiles (rescue agents) have been investigated using stopped-flow and UV/VIS spectrophotometry. Glutathione (GSH) reduction of the anticancer active Pt(IV) compounds t- and c-[PtCl4(cha)(NH3)] (cha = cyclohexylamine), t-[PtCl4(thiazole)(NH3)] and c-[PtCl4(NH3)2] at 25 oC was observed to be very fast. READ MORE

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

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

   Abstract : 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. READ MORE

6. 19. NH3-SCR chemistry for NOx abatement: Influence of zeolite support on N2O formation & phosphorus species addition

   Author : Joonsoo Han; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Copper; NH3 SCR chemistry; Zeolite topology; N2O; Phosphorus poisoning;

   Abstract : Different lattice arrangements of Si, Al, and O atoms result in a variety of pore dimensions and zeolite channel network systems, giving rise to different physicochemical environments inside the catalyst cage. The objective of the thesis work was to understand the influence of zeolite topology on NH3-assisted SCR chemistry over CHA, MFI, and BEA frameworks, on the formation of N2O and the addition of phosphorus species to attain fundamental insight into NOx emission control. READ MORE

7. 20. Fundamentals of NH3-SCR and SOx chemistry over copper zeolite for the control of NOx and greenhouse gas (N2O) emissions

   Author : Joonsoo Han; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; DeNOx; Cu SSZ-13; NH3-SCR; N2O; EATS; SO3; ammonium nitrate; SO2;

   Abstract : The release of N2O over Cu-zeolite was investigated due to the critical contribution it makes to the atmosphere as one of the greenhouse gases (GHGs). An exhaust after-treatment system (EATS) for heavy-duty vehicles that uses Cu/SSZ-13 as the selective catalyst reduction (SCR) catalyst experiences not only a variety of flow, temperature and chemical conditions but is also exposed to various resulting contaminants. READ MORE