Sökning: "Acid catalysts"

Visar resultat 1 - 5 av 117 avhandlingar innehållade orden Acid catalysts.

1. 1. Nanostructured Fuel Cell Catalysts

   Författare :Marie Gustavsson; Chalmers tekniska högskola; []
   Nyckelord :Nafion; thin film evaporation; model catalyst; electrocatalyst; acetic acid oxidation; oxygen reduction; colloidal lithography; PEMFC; screening; Pt; formaldehyde oxidation; methanol oxidation; nanofabrication; CO oxidation; polymer electrolyte; TiOx;

   Sammanfattning : A long term challenge for society is to develop sustainable energy systems to reduce the dependence on fossil fuels and to decrease air pollution. This requires new alternatives regarding the supply of energy and increased efficiency of the future energy systems. Fuel cell technology is one such possible alternative. LÄS MER

3. 2. Formic and Levulinic Acid from Cellulose via Heterogeneous Catalysis

   Författare :Johan Ahlkvist; Jyri-Pekka Mikkola; Riitta Keiski; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Levulinic acid; formic acid; Amberlyst 70;

   Sammanfattning : The chemical industry of today is under increased pressure to develop novel green materials, bio-fuels as well as sustainable chemicals for the chemical industry. Indeed, the endeavour is to move towards more eco-friendly cost efficient production processes and technologies and chemical transformation of renewables has a central role considering the future sustainable supply of chemicals and energy needed for societies. LÄS MER

4. 3. Acid-catalyzed Liquefaction of Industrial Side-streams for Producing Wood Adhesives and Particleboard

   Författare :Wen Jiang; Stergios Adamopoulos; Sheikh Ali Ahmed; Sergej Medved; Carsten Mai; Johannes Konnerth; Linnéuniversitetet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Bark; Catalysts; Industrial side-streams; Liquefaction; Oat husks; Optimization; Particleboards; Polyurethane; Polyhydric alcohols; Wood adhesives; Wood sawdust; Forestry and Wood Technology; Skog och träteknik;

   Sammanfattning : Big quantities of residues and side-streams are generated annually from forest-based and agricultural industries all around the world and present a relatively unexplored renewable resource. Due to the absence of a regularly updated and systematic database of supply, industrial residues and side-streams usually end up in landfill disposal, are used for energy generation, or remain at the production sites. LÄS MER

5. 4. Alkylation and Hydrodearomatization over Zeolite cCatalysts

   Författare :Jun-Jun Yuan; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Acid catalysts; ZSM-5 catalysts; ethylbenzene; toluene; temperature; diesel fuel; hydrodearomatization; benzene; acidic protons; activity and selectivity; aqueous ethanol; Pt Y zeolite; gasoline; pressure; GC; diethylbenzene; Hydrocracking; SiO2 Al2O3 ratio; alkylation of aromatics; Brønsted acids;

   Sammanfattning : The alkylation of aromatic compounds is widely used in the large-scale synthesis of petrochemicals, and a great variety of fine chemicals and intermediates. Acid catalysts used for alkylation of aromatic hydrocarbons are Brønsted acids containing acidic protons. LÄS MER

7. 5. Expanding the Amino Acid Alphabet by Design : Enhanced and Controlled Catalytic Activity in Folded Polypeptide Catalysts

   Författare :N. Johan V. Lindgren; Lars Baltzer; Harri Lönnberg; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Chemistry; Kemi; Organic Chemistry; organisk kemi;

   Sammanfattning : This thesis addresses structure and reactivity of polypeptide catalysts in reactions that mimic the hydrolysis of RNA and DNA. A designed helix-loop-helix motif was used as a scaffold where the amino acid residues were systematically varied. LÄS MER