In order to correlate the properties of the catalyst to those of the support, activated carbons from various raw materials and activation methods were fully characterised in terms of their physical properties, surface chemistry and elemental composition. Significant differences were identified whereby the porosity of the carbon, and hence the surface area, varied with the raw material used whilst the surface chemistry depended on the method of activation. The interdependence of the carbon properties made it difficult to isolate particular carbon features which were responsible for the catalytic properties. As such, a wood carbon was subjected to a variety of oxidative and reductive treatments aimed at altering the surface chemistry whilst maintaining the pore structure. 5% platinum on carbon catalysts were prepared on each of the carbons using an excess solution impregnation of hexachloroplatinic acid under two sets of preparation conditions. Significant differences in metal dispersion and catalytic activity were identified and attributed to features of the carbon support, with both the pore structure and the surface chemistry playing significant roles. The prepared materials were used as catalysts for the selective hydrogenation of cinnamaldehyde. Selectivity and activity were shown to be affected by the support which could be attributed to both the physical and chemical nature of the carbon. As a result it may be possible to select a particular carbon support that would produce an active catalyst for a particular reaction.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:590963 |
| Date | January 2007 |
| Creators | Leith, M. G. A. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0068 seconds