Sökning: "Sustainable catalysis"

Visar resultat 21 - 25 av 53 avhandlingar innehållade orden Sustainable catalysis.

1. 21. Deactivation of after-treatment catalysts for bio-fuelled engines

   Författare :Johanna Englund; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 22. Spectroscopic investigation of palladium catalysts during wet methane oxidation

   Författare :Peter Velin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Methane oxidation; Water inhibition; XAS; DRIFTS; Supported palladium; Environmental catalysis; Operando spectroscopy; Sustainable transports;

   Sammanfattning : Abatement of the strong greenhouse gas methane in vehicle applications by use of catalytic end-of-pipe technologies is challenging due to the prevailing reaction conditions with low temperatures and high water content. In this thesis, the mechanisms behind low-temperature water inhibition of lean methane oxidation over palladium-based catalysts have been studied using an integrated experimental approach including wet-chemical preparation of model catalysts with systematic variation of key performance parameters, transient measurements of reaction kinetics in chemical flow reactor, and operando infrared and X-ray absorption spectroscopic characterisation. LÄS MER

4. 23. Secondary Interactions in Symmetric Double Bond Formation Catalysed by Molecular Ruthenium Complexes

   Författare :Oleksandr Kravchenko; Licheng Sun; Roger Alberto; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homogeneous catalysis; transition metal catalysis; ruthenium catalyst; olefin metathesis; dynamic covalent chemistry; water oxidation; solar fuels; Ru-bda; secondary interactions; hydrophobic interactions; π-π stacking; homogen katalys; övergångsmetallkatalys; rutheniumkatalysator; olefinmetates; dynamisk kovalent kemi; vattenoxidation; solbränslen; Ru-bda; sekundära interaktioner; hydrofoba interaktioner; π-π stapling; Kemi; Chemistry;

   Sammanfattning : Chemistry has a tremendous impact on everyone’s life, although society does not always realize its power and ubiquity. In recent years, improved economy and sustainability of chemical processes has become a worldwide priority. LÄS MER

5. 24. Metal-Free Catalysis for Efficient Synthesis

   Författare :Juho Bah; Johan Franzén; King Kuok (Mimi) Hii; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Homogeneous c atalysi s; O rga nocatalysis; Green C hemistry; T o tal S ynthesis; A lkaloids; A symmetric S ynthesis; N on - metal Lewis acid s; C arbocations; Sustainability; Kemi; Chemistry;

   Sammanfattning : The strength of efficient metal-free catalysis will be examined in this thesis. Efforts towards more sustainable processes will be demonstrated through implementation of strategies that meet several of the 12 principles of Green Chemistry. LÄS MER

7. 25. Farm to furan derivatives : Fractionation of agricultural residues and transformation of sugars to chemical building blocks

   Författare :Sara Jonsdottir Glaser; Bioteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biorefinery; sugar beet pulp; wheat bran; agricultural residue; biomass valorisation; fractionation; bio-based platform chemicals; HMF; levulinic acid; heterogeneous catalysis; whole-cell catalysis;

   Sammanfattning : The transition of industrial production from petrochemistry to a more sustainable economy requires the use of carbon neutral, renewable feedstock, which does not compete with food and feed supplies – by-products of farming and agro-food industry offer this possibility. With a limited range of low-value applications today coupled with the need for maximal utilisation of resources, the by-products of farming can be repurposed as feedstock for biorefineries. LÄS MER