Search for dissertations about: "Rhodium"
Showing result 11 - 15 of 67 swedish dissertations containing the word Rhodium.
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11. Development of a regeneration procedure for commercial automotive three-wy catalysts
Abstract : Car exhaust catalysts were introduced in the early 1980’s, to limit the release of pollutants such as hydrocarbons, carbon monoxides and nitrogen oxides. These catalysts contain noble metals such as palladium (Pd), platinum (Pt) and rhodium (Rh) and are able to simultaneously abate all three of the above-mentioned pollutants, hence the name three-way catalyst (TWC). READ MORE
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12. Asymmetric transfer hydrogenation of ketones : Catalyst development and mechanistic investigation
Abstract : The development of ligands derived from natural amino acids for asymmetric transfer hydrogenation (ATH) of prochiral ketones is described herein. In the first part, reductions performed in alcoholic media are examined, where it is found that amino acid-derived hydroxamic acids and thioamides, respectively, are simple and versatile ligands that in combination with [RhCp*Cl2]2 efficiently catalyze this particular transformation. READ MORE
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13. Experimental Studies of NOx Catalysts; Storage, Reduction and Sulphur Deactivation
Abstract : The aim of this thesis work was to investigate how different gaseous compounds, present in an automotive exhaust from lean-tuned combustion, interact with so-called NOx storage catalysts containing Al2O3 as a support, BaO as the NOx storage compound and noble metals to provide oxidation and reduction functions. The investigations included model sample preparations, flow reactor studies with various gas mixtures and spectroscopic experiments (FTIR and XPS). READ MORE
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14. Transition metal-catalyzed reduction of carbonyl compounds : Fe, Ru and Rh complexes as powerful hydride mediators
Abstract : A detailed mechanistic investigation of the previously reported ruthenium pseudo-dipeptide-catalyzed asymmetric transfer hydrogenation (ATH) of aromatic ketones was performed. It was found that the addition of alkali metals has a large influence on both the reaction rate and the selectivity, and that the rate of the reaction was substantially increased when THF was used as a co-solvent. READ MORE
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15. Platinum Group Elements in Birds of Prey
Abstract : The environmental concentrations of Pd, Pt and Rh (three of the platinum group elements, PGE) have increased since the introduction of exhaust catalysts on automobiles. A limited understanding of the environmental distribution and effects of the platinum group elements has raised concern over their potential biological availability. READ MORE