Ni/Mg/Al containing anionic clays of hydrotalcite-type structure with varying Ni/Mg ratio and constant Al content were synthesised by coprecipitation. Their composition and structure was determined by elemental analysis, XRD, TG-MS and DSC. Their calcination at 700-1000°C resulted in the transformation into the corresponding mixed metal oxides, with their structure depending on the calcination temperature. Temperature programmed reduction/oxidation and high temperature XRD studies were applied to study their reducibility, Ni dispersion and the oxidation of the formed metallic nickel particles. The partial oxidation of propane to syngas could be successfully performed at temperatures between 600 and 900°C over reduced Ni containing catalysts. The conversion of propane and the yield of syngas increased with increasing reaction temperature. The catalysts with a low to medium Ni content exhibited better catalytic performance than those with a higher Ni content or a conventional steam reforming catalyst used as reference. Coking was found to decrease with increasing reaction temperature and to increase with increasing Ni content. Since several factors characterising the catalysts (BET surface area, Mg content and available Ni surface) follow the same or the opposite trend with the Ni content, it was impossible to differentiate between these properties and their effect on the catalyst performance or coking. By the use of the best catalyst an at least two-fold increase in the yield of carbon monoxide and eight-fold increase in the yield of hydrogen was observed compared with the non-catalytic reaction. Further investigations were performed to study the influence of the feed ratio and the space velocity.
| Identifer | oai:union.ndltd.org:DUETT/oai:DUETT:duett-09202001-103759 |
| Date | 24 September 2001 |
| Creators | Schulze, Kai |
| Contributors | Prof. Dr. Günter Geismar, Prof. Dr. Roman Dziembaj (Universität Krakau) |
| Publisher | Gerhard-Mercator-Universitaet Duisburg |
| Source Sets | Dissertations and other Documents of the Gerhard-Mercator-University Duisburg |
| Language | German |
| Detected Language | English |
| Type | text |
| Format | text/html, application/pdf |
| Source | http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-09202001-103759/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. Hiermit erteile ich der Universitaet Duisburg das nicht-ausschliessliche Recht unter den unten angegebenen Bedingungen, meine Dissertation, Staatsexamens- oder Diplomarbeit, meinen Forschungs- oder Projektbericht zu veroeffentlichen und zu archivieren. Ich behalte das Urheberrecht und das Recht das Dokument zu veroeffentlichen und in anderen Arbeiten weiterzuverwenden. |
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