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Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media
Dissertation (MSc)--University of Pretoria, 2011.
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| Format: | Thesis |
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University of Pretoria
2013
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| _version_ | 1867613470022696960 |
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| access_status_str | Open Access |
| author2 | Ozoemena, Kenneth I. |
| author_browse | Ozoemena, Kenneth I. |
| author_facet | Ozoemena, Kenneth I. |
| collection | Thesis |
| dc_rights_str_mv | © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2011. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/31292 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:39.169Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/31292 Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media Ozoemena, Kenneth I. thendaiz@yahoo.com Van der Merwe, Liesel Laura Ramulifho, Tendamudzimu UCTD Dissertation (MSc)--University of Pretoria, 2011. An electrocatalyst plays an important role in the alcohol oxidation reaction in fuel cells. Palladium based electrocatalysts are one of the promising candidates for alcohol oxidation in direct alcohol alkaline fuel cells. This study reports the preparation of metal nanoparticles (Pd, Ni, and Sn) supported on sulfonated multi-walled carbon nanotubes (SF-MWCNTs) using a microwave-assisted solvothermal method. The physical properties of the prepared electrocatalysts were investigated using several techniques such as TEM, EDX, XRD, FTIR and Raman spectroscopy. The electrocatalytic behaviour of the SF-MWCNT-Pd and its mixtures (i.e., SF-MWCNT-PdSnmix and SF-MWCNT-PdNimix) towards ethanol and ethylene glycol oxidation in alkaline medium were investigated. The results show that the mixed Pd-based catalysts gave better electrocatalytic activity than their alloy nanoparticles or Pd alone. The SF-MWCNT platform gave better electrocatalytic performance compared to the unsulfonated and commercial vulcan carbon. Detailed electrochemical studies (involving cyclic voltammetry, chronoamperometry, chronopotentiometry, and impedance spectroscopy) prove that the electrocatalytic oxidation of ethanol at the SF-MWCNT-PdNimix platform is more stable, occurs at lower potential, and gives lower Tafel slopes, with faster charge-transfer kinetics compared to its SF-MWCNT-PdSnmix counterpart. The results also revealed that SF-MWCNT-PdNimix is more tolerant to CO poisoning than the SF-MWCNT-PdSnmix during ethanol oxidation in alkaline medium. However, the SF-MWCNT-PdSnmix electrocatalyst showed better electrocatalytic behaviour for ethylene glycol oxidation in alkaline medium; with high current response, better stability and low Tafel slopes. Both (SF-MWCNT-PdNimix and SF-MWCNT-PdSnmix) electrocatalysts showed comparable behaviour towards CO poisoning during ethylene glycol oxidation in alkaline medium. The results obtained provide some important insights into the electrochemical response of microwave synthesised Pd-based bimetallic catalysts for potential application in direct alcohol alkaline fuel cell technology. Chemistry Unrestricted 2013-09-09T12:10:24Z 2011-09-23 2013-09-09T12:10:24Z 2011-09-09 2011-09-23 2011-09-23 Dissertation Ramulifho, T 2011, Carbon nanotube – supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/31292 > E11/9/172/hv http://hdl.handle.net/2263/31292 http://upetd.up.ac.za/thesis/available/etd-09232011-131842/ © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title | Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title_full | Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title_fullStr | Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title_full_unstemmed | Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title_short | Carbon nanotube : supported bimetallic nanocatalysts for the electro-oxidation of alcohols in alkaline media |
| title_sort | carbon nanotube supported bimetallic nanocatalysts for the electro oxidation of alcohols in alkaline media |
| topic | UCTD |
| url | http://hdl.handle.net/2263/31292 http://upetd.up.ac.za/thesis/available/etd-09232011-131842/ |