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SiC and B₄C as electrocatalyst support materials for low temperature fuel cells
Supported nano-catalyst technologies are key for increasing the catalyst utilisation and achieving economically feasible platinum metal loadings in hydrogen polymer electrolyte fuel cells (PEFCs). High surface area carbons are commonly utilised as support materials for platinum due to low cost, larg...
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| Format: | Thesis |
| Language: | English |
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Centre for Catalysis Research
2018
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| _version_ | 1867613150237425664 |
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| access_status_str | Open Access |
| author | Jackson, Colleen |
| author2 | Levecque, Pieter B J |
| author_browse | Jackson, Colleen Levecque, Pieter B J |
| author_facet | Levecque, Pieter B J Jackson, Colleen |
| author_sort | Jackson, Colleen |
| collection | Thesis |
| description | Supported nano-catalyst technologies are key for increasing the catalyst utilisation and achieving economically feasible platinum metal loadings in hydrogen polymer electrolyte fuel cells (PEFCs). High surface area carbons are commonly utilised as support materials for platinum due to low cost, large surface areas and high conductivity. However, PEFCs using this technology undergo oxidation of carbon supports, significantly reducing the lifetime of the fuel cell. In this work, silicon carbide and boron carbide are investigated as alternative catalyst support materials to carbon, for the oxygen reduction reaction for low temperature fuel cells. Electrochemical testing, accelerated degradation studies as well as advanced characterisation techniques were used to clarify the structure-property relationships between catalyst morphology, metal-support interaction, ORR activity and surface adsorption onto the Pt nanoparticles. Extended X-ray Absorption Fine Structure (EXAFS) analysis gave insights into the shape of the clustered nanoparticles while X-ray Photoelectron Spectroscopy (XPS) and in-situ X-ray Absorption Near-Edge Spectroscopy (XANES) analysis provided information into how the metal-support interaction influences surface adsorption of intermediate species. Electronic metal-support interactions between platinum and the carbide supports were observed which influenced the electrochemical characteristics of the catalyst, in some cases increasing the oxygen reduction reaction activity, hydrogen oxidation reaction activity and Pt stability on the surface of the support. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/27313 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:31:34.243Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2018 |
| publishDateRange | 2018 |
| publishDateSort | 2018 |
| 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:11427/27313 SiC and B₄C as electrocatalyst support materials for low temperature fuel cells Jackson, Colleen Levecque, Pieter B J Kramer, Denis Russell, Andrea E Catalysis Research Chemical Engineering Supported nano-catalyst technologies are key for increasing the catalyst utilisation and achieving economically feasible platinum metal loadings in hydrogen polymer electrolyte fuel cells (PEFCs). High surface area carbons are commonly utilised as support materials for platinum due to low cost, large surface areas and high conductivity. However, PEFCs using this technology undergo oxidation of carbon supports, significantly reducing the lifetime of the fuel cell. In this work, silicon carbide and boron carbide are investigated as alternative catalyst support materials to carbon, for the oxygen reduction reaction for low temperature fuel cells. Electrochemical testing, accelerated degradation studies as well as advanced characterisation techniques were used to clarify the structure-property relationships between catalyst morphology, metal-support interaction, ORR activity and surface adsorption onto the Pt nanoparticles. Extended X-ray Absorption Fine Structure (EXAFS) analysis gave insights into the shape of the clustered nanoparticles while X-ray Photoelectron Spectroscopy (XPS) and in-situ X-ray Absorption Near-Edge Spectroscopy (XANES) analysis provided information into how the metal-support interaction influences surface adsorption of intermediate species. Electronic metal-support interactions between platinum and the carbide supports were observed which influenced the electrochemical characteristics of the catalyst, in some cases increasing the oxygen reduction reaction activity, hydrogen oxidation reaction activity and Pt stability on the surface of the support. 2018-02-05T13:06:47Z 2018-02-05T13:06:47Z 2017 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/27313 eng application/pdf Centre for Catalysis Research Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Catalysis Research Chemical Engineering Jackson, Colleen SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| thesis_degree_str | Doctoral |
| title | SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| title_full | SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| title_fullStr | SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| title_full_unstemmed | SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| title_short | SiC and B₄C as electrocatalyst support materials for low temperature fuel cells |
| title_sort | sic and b₄c as electrocatalyst support materials for low temperature fuel cells |
| topic | Catalysis Research Chemical Engineering |
| url | http://hdl.handle.net/11427/27313 |
| work_keys_str_mv | AT jacksoncolleen sicandb4caselectrocatalystsupportmaterialsforlowtemperaturefuelcells |