Studies in synthesis-structure-function relationships in oxide-supported platinum catalysts

This work has involved the synthesis, and the physical and chemical characterisation, and reactor studies of oxide-supported platinum catalysts. Eight nominally identical catalysts with different preparation histories and hence different structure are the main subjects of these studies. Platinum-silica catalysts have been prepared using different types of silica, and the silicas have been exposed to different pre-treatments. Furthermore, different solvents and different platinum containing compounds have been used to deposit the metal on the silica. The aims of this work have been twofold. One has been the study of the relationships between the synthesis and structure, and between structure and performance of these oxide-supported platinum catalysts. The other aim has been to better understand the phenomenon of catalysis, to study the surface processes that constitute the reaction mechanism and also the differences in these processes on structurally different catalysts and different operating conditions. Pore structure studies have been made on alumina pastes using mercury porosimetry, and a novel method in the use of this technique has been applied to platinum-alumina catalysts and found to be successful. This study is unique in the field of heterogeneous catalysis, in that the silica surface structure has been systematically and quantitatively investigated for a wide range of catalysts using 29Si NMR and Raman spectroscopies. NMR and Raman spectroscopies, which are characterisation tools in the studies of silica, have been applied in the study of platinum-silica catalysts and have been shown to provide complementary information. The metal characteristics have also been reported. Temperature-programmed desorption of ethene and ethyne have been performed to provide information on the desorption properties.EThOS - Electronic Theses Online ServiceGBUnited Kingdo