Search for dissertations about: "Cu catalyst"

Showing result 1 - 5 of 65 swedish dissertations containing the words Cu catalyst.

2. 1. Dynamics and Reactivity of Cu-species in Cu-CHA for NH3-SCR

   Author : Joachim Bjerregaard; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Machine Learning Force Field; Diffusion; Cu-CHA; NH3-SCR; DFT; Sulfur Deactivation;

   Abstract : Copper exchanged chabazite (Cu-CHA) is a state-of-the-art catalyst for deNOx via ammonia assisted selective catalytic reduction (NH3-SCR) in lean burn engines, owing to its good low-temperature activity, and high hydrothermal stability. One challenge for Cu-CHA is, however, the sensitivity to sulfur species, which are present in the exhaust gas. READ MORE

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

   Author : Johanna Englund; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Asymmetric Formation and Isomerization of Three-Membered Rings : Catalyst Development and Evaluation

   Author : Sophie Bertilsson; Tobias Rein; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; allylic alcohol; α-amino acid derivative; aza-Diels-Alder reaction; aziridination; cyclopropanation; desymmetrization; epoxide rearrangement; kinetic resolution; lithium amide; rhodium-carboxylate; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

   Abstract : Enantiopure α-amino acid derivatives were prepared using a protocol which allows for highly controlled regio- and chemoselectivity in the hydrogenation/ hydrogenolysis of aza-Diels-Alder adducts. One of the resulting α-amino esters, (1S,3R,4R)-2-azabicyclo[2.2.1]heptane-3-carboxylic acid ethyl ester, was utilized further as a catalyst precursor. READ MORE

6. 4. Deactivation of emission control catalysts for heavy-duty vehicles : Impact of biofuel and lube oil-derived contaminants

   Author : Sandra Dahlin; Lars Pettersson; Isabella Nova; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; catalyst deactivation; diesel oxidation catalyst; sulfur; phosphorus; biodiesel; heavy-duty; emission control; regeneration; alkali metals; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; katalysatordeaktivering; dieseloxidationskatalysator; svavel; fosfor; biodiesel; tunga dieselmotorer; avgasrening; regenerering; alkalimetaller; Chemical Engineering; Kemiteknik;

   Abstract : Catalytic emission control is used to reduce the negative impact of pollutants from diesel exhausts on our health and on the environment. For a heavy-duty truck, such a system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia slip catalyst (ASC). READ MORE

7. 5. Reaction kinetics of NH3-SCR over Cu-CHA from first principles

   Author : Yingxin Feng; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Catalysis; microkinetic modeling; density functional theory; Cu-CHA; ammonia assisted selective catalytic reduction;

   Abstract : Ammonia-assisted selective catalytic reduction (NH3-SCR) is an advanced technology to reduce nitrogen oxide (NOx) emissions from lean-burn engines. NH3 is added to the exhaust gas and reacts selectively with NOx, forming N2 and H2O. READ MORE