Sökning: "two-step evolution"

Visar resultat 6 - 10 av 15 avhandlingar innehållade orden two-step evolution.

1. 6. Molecular Motion in Frustrated Lewis Pair Chemistry: insights from modelling

   Författare :Maoping Pu; Timofei Privalov; Todd Martinez; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; CO2 capture; hydrogen activation; molecular motion; ab initio molecular dynamics; frustrated Lewis pair; quantum chemical modelling; reaction mechanism; Organic Chemistry; organisk kemi;

   Sammanfattning : Mechanisms of reactions of the frustrated Lewis pairs (FLPs) with carbon dioxide (CO2) and hydrogen (H2) are studied by using quantum chemical modelling. FLPs are relatively novel chemical systems in which steric effects prevent a Lewis base (LB) from donating its electron pair to a Lewis acid (LA). LÄS MER

3. 7. Li2O2 quantification in non-aqueous Li-O2 batteries with binder-free cathodes

   Författare :Chenjuan Liu; Torbjörn Gustafsson; Martin Sahlberg; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The non-aqueous Li-air (Li-O2) battery has been emerging as one of the most promising high-energy storage systems to meet the requirements for electric vehicle applications due to its high theoretical energy density. In order to uncover the underlying electrochemistry and enable an informed battery design, it is crucial to gain a detailed understanding of the cell´s chemical components as well as its behavior during cycling. LÄS MER

4. 8. ToF-SIMS as a tool for analysing organic material in geological samples -Fluid inclusions and beyond

   Författare :Sandra Siljeström; Jukka Lausmaa; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organic material; ToF-SIMS; Other earth sciences; Övrig geovetenskap; geokemi; Geochemistry;

   Sammanfattning : In situ analysis of organic material in rocks has potential to answer questions in geochemistry, astro- and geobiology. Recently, successful studies which included in situ analyses of geological samples with time-of-flight secondary ion mass spectrometry (ToF-SIMS) were carried out. LÄS MER

5. 9. Investigation of Coordination Modes of Organosulfur Ligands to osmium and Rhodium Carbonyl Clusters- Possible Relevance to Hydrodesulfurization Reactions

   Författare :Nitsa Kiriakidou-Kazemifar; Kemiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; thioethers; thiols; HDS processes; organosulfur compounds; polynuclear metal complexes; Metallorganisk kemi; Organometallic chemistry; thiophenes;

   Sammanfattning : The coordination and fundamental transformations of organosulfur compounds to polynuclear metal complexes has been studied as models for possible surface species in industrial HDS processes. Reactions between [Os3(CO)11(NCMe)] and various thiols have been studied by UV-Vis, IR and NMR spectroscopy and all experimental findings indicate that the reactions proceed via a two-step consecutive process involving the intermediate [Os3(CO)11(RSH)], which contains an agostic Os-H-S interaction, and which leads to the formation of the final product [Os3(CO)10(m-H)(m-SR)]. LÄS MER

7. 10. Development of ring-opening catalysts for diesel quality improvement

   Författare :Ulf Nylén; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ring opening; naphthenes; cetane number improvement; indan; light cycle oil LCO ; Pt-Ir catalyst; catalyst characterization; aromatic sulphur compounds; GC-SCD; distribution; analysis;

   Sammanfattning : The global oil refining industry with its present shift inproduct distribution towards fuels such as gasoline and dieselwill most likely hold the fort for many years to come. However,times will change and survival will very much depend onprocessing flexibility and being at the frontiers of refiningtechnology, a technology where catalysts play leading roles. LÄS MER