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Nanosized iron crystallites for Fischer-Tropsch synthesis
Includes bibliographical references (p. 131-148).
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Centre for Catalysis Research
2014
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| _version_ | 1867613298898239488 |
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| access_status_str | Open Access |
| author | Mabaso, Evans Itai |
| author2 | Claeys, Michael |
| author_browse | Claeys, Michael Mabaso, Evans Itai |
| author_facet | Claeys, Michael Mabaso, Evans Itai |
| author_sort | Mabaso, Evans Itai |
| collection | Thesis |
| description | Includes bibliographical references (p. 131-148). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/8736 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:33:55.830Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Centre for Catalysis Research |
| publisherStr | Centre for Catalysis Research |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/8736 Nanosized iron crystallites for Fischer-Tropsch synthesis Mabaso, Evans Itai Claeys, Michael Civil Engineering Includes bibliographical references (p. 131-148). Fischer-Tropsch synthesis is the production of hydrocarbons from CO and H2. The catalytically active metals for industrial application are cobalt and iron. In this work iron-based catalysts were studied. To ensure maximum metal utilisation and therefore a high weight specific catalytic activity, the metal crystallites should possess large specific surface areas and that is only achievable with small metal crystallites. However, a minimum crystallite size might exist below which catalyst activity drops. Consequently, in order to investigate the role of crystallite size on the stability, the activity and selectivity of iron based catalysts, supported catalysts with a known narrow metal crystallite size distribution were prepared via precipitation in water-in-oil microemulsions in which water-to-surfactant ratio was the main design parameter. The study was subdivided into firstly characterisation of a suitable water-in-oil microemulsion system. Secondly preparation of nanosized oxidic iron crystallites with controlled crystallite size via precipitation in water-in-oil microemulsion. Thirdly preparation of the supported catalyst using the same but selected microemulsion systems. Finally catalyst testing under Fischer-Tropsch reaction conditions in a fixed bed reactor. A strictly linear relationship between water-to-surfactant ratio and crystallite size was observed. The catalyst preparation technique for unsupported iron oxides resulted in uniform nanocrystallites tailored to a size range of 2-16 nm. The morphology of the crystallites on supports remained largely unchanged upon reductive pretreatment. This made catalysts prepared in microemulsions ideally suitable for investigating the effect of crystallite size during Fischer-Tropsch synthesis. 2014-10-23T07:11:30Z 2014-10-23T07:11:30Z 2005 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/8736 eng application/pdf Centre for Catalysis Research Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Civil Engineering Mabaso, Evans Itai Nanosized iron crystallites for Fischer-Tropsch synthesis |
| thesis_degree_str | Doctoral |
| title | Nanosized iron crystallites for Fischer-Tropsch synthesis |
| title_full | Nanosized iron crystallites for Fischer-Tropsch synthesis |
| title_fullStr | Nanosized iron crystallites for Fischer-Tropsch synthesis |
| title_full_unstemmed | Nanosized iron crystallites for Fischer-Tropsch synthesis |
| title_short | Nanosized iron crystallites for Fischer-Tropsch synthesis |
| title_sort | nanosized iron crystallites for fischer tropsch synthesis |
| topic | Civil Engineering |
| url | http://hdl.handle.net/11427/8736 |
| work_keys_str_mv | AT mabasoevansitai nanosizedironcrystallitesforfischertropschsynthesis |