Student Number : 0303610W -
PhD thesis -
School of Chemistry -
Faculty of Science / Mesoporous MCM-48 was synthesized and used as a template to synthesize
mesoporous carbon (MC) materials. Polystyrene, the carbon source, together with
sulfuric acid and toluene were added to the template (160 oC for 6 h) and this
procedure generated a low surface area carbon supported/MCM-48 material. A
repeat addition and carbonization step was needed to form the precursor
carbon/MCM-48 material that was pyrolysed at 900 oC to generate graphitic
mesoporous carbon materials. After removal of the silica template, mesoporous
carbons were characterized by XRD, HR-TEM, Raman spectroscopy and surface
area analysis. The effect of the amount of polystyrene as well as the role of the
pyrolysis temperature on the final product was investigated. This synthesis
methodology can readily be controlled to produce partially ordered graphitic
mesoporous carbon supports with predictable pore width and surface area.
The methane selectivity was low (below 6%) and stable, and the overall olefin
fraction was found to be good for all the supported catalysts studied. The
potassium promoter increased the hydrocarbon chain growth to C68 giving α-1 and
α-2 both between 0.79 and 0.90 for all supported catalysts with an exception of
MCM-48 supported Fe catalyst that selectively produced hydrocarbons up to C28.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/2058 |
| Date | 21 February 2007 |
| Creators | Mbileni, Charity Nonkululeko |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 5356382 bytes, application/pdf, application/pdf |
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