The synthesis of nitrogen doped carbon spheres as supports for palladium catalysts in the hydrogenation of cinnamaldehyde
Manikai, Sibongile Mary-Anne
The selective hydrogenation of cinnamaldehyde (CALD), an α,β-unsaturated aldehyde, at the carbonyl (C=O) and olefinic (C=C) groups is an important reaction since its products mainly cinnamyl alcohol (CA) and hydrocinnamaldehyde (HCALD) are important intermediates for the production of many chemicals in a wide range of industries (pharmaceuticals, flavouring, agrochemicals, perfume). In this study the synthesis of nitrogen doped carbon spheres (NCSs) as catalyst supports for the hydrogenation of CALD is reported. At the heart of the hydrogenation of CALD is the catalyst, since it provides the surface for the various reactions to take place. In this study, an in-depth study was conducted on the NCSs support, by varying pyrolysis time, pyrolysis temperatures and flow rates of gases to determine the physical and chemical properties. The effects of chemically modifying the surfaces of the NCS supports by functionalization with acid and doping with carbon were also investigated. NCSs which had undergone different pre-treatments procedures were then deposited with Pd nanoparticles using different metal deposition methods and the resultant catalysts tested for the hydrogenation of CALD.
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry. Johannesburg, 2015.