Characterisation of PtMo and PtW electrocatalysts for fuel cells using in-situ XAS and INS techniques
Characterisation of PtMo and PtW electrocatalysts for fuel cells using in-situ XAS and INS techniques
The continuing development of catalysts for hydrogen oxidation in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) requires a greater understanding of the catalyst structure and how this relates to the performance, as well as knowledge of the mechanism taking place.
The electrocatalytic activity of a series of carbon supported PtMo and PtW anode catalysts towards the electro-oxidation of CO and oxidation of methanol was studied. An in-situ X-ray Absorption Spectroscopy (XAS) mini cell was used in order to obtain data using fluorescence detection. It was found that catalysts prepared by the co-deposited method were the most well-mixed, although not at all alloyed, with the samples consisting of Pt-rich cores with oxides of the secondary metal being prominent at the surface. Operating conditions were seen to be significant, with the co-deposited PtMo samples capable of being oxidised with potential in both half cell and mini cell conditions. A PtMo catalyst with a 2: 1 ratio had the highest activity for hydrogen oxidation when operating with reformate fuel streams. Preparation of a surface modified PtMo/C catalyst was achieved using an organometallic precursor and found to offer good control of the deposition of the Mo.
Inelastic Neutron Scattering (INS) studies were carried out on Pt and PtMo-based electrocatalysts to investigate the interactions of the H2 molecule and hydrogen and carbon monoxide modified surfaces. For the Pt/C catalyst it was found that the hydrogen atoms are located predominantly in hollow (three-fold) sites on Pt(111), with some contribution from hydrogen on multi-fold adsorption sites on a Pt(110) plane. Dihydrogen molecules were seen to interact strongly with the H/Pt surface for the Pt and PtMo based catalysts, while only a weak interaction was observed with the carbon monoxide-modified surface.
University of Southampton
King, Colin Ross
afa9b1f8-ab5a-4600-92ee-1f8828126d97
2007
King, Colin Ross
afa9b1f8-ab5a-4600-92ee-1f8828126d97
King, Colin Ross
(2007)
Characterisation of PtMo and PtW electrocatalysts for fuel cells using in-situ XAS and INS techniques.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The continuing development of catalysts for hydrogen oxidation in Polymer Electrolyte Membrane Fuel Cells (PEMFCs) requires a greater understanding of the catalyst structure and how this relates to the performance, as well as knowledge of the mechanism taking place.
The electrocatalytic activity of a series of carbon supported PtMo and PtW anode catalysts towards the electro-oxidation of CO and oxidation of methanol was studied. An in-situ X-ray Absorption Spectroscopy (XAS) mini cell was used in order to obtain data using fluorescence detection. It was found that catalysts prepared by the co-deposited method were the most well-mixed, although not at all alloyed, with the samples consisting of Pt-rich cores with oxides of the secondary metal being prominent at the surface. Operating conditions were seen to be significant, with the co-deposited PtMo samples capable of being oxidised with potential in both half cell and mini cell conditions. A PtMo catalyst with a 2: 1 ratio had the highest activity for hydrogen oxidation when operating with reformate fuel streams. Preparation of a surface modified PtMo/C catalyst was achieved using an organometallic precursor and found to offer good control of the deposition of the Mo.
Inelastic Neutron Scattering (INS) studies were carried out on Pt and PtMo-based electrocatalysts to investigate the interactions of the H2 molecule and hydrogen and carbon monoxide modified surfaces. For the Pt/C catalyst it was found that the hydrogen atoms are located predominantly in hollow (three-fold) sites on Pt(111), with some contribution from hydrogen on multi-fold adsorption sites on a Pt(110) plane. Dihydrogen molecules were seen to interact strongly with the H/Pt surface for the Pt and PtMo based catalysts, while only a weak interaction was observed with the carbon monoxide-modified surface.
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Published date: 2007
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Local EPrints ID: 466180
URI: http://eprints.soton.ac.uk/id/eprint/466180
PURE UUID: b47aee3e-37e8-4029-85be-af7442069f12
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Date deposited: 05 Jul 2022 04:39
Last modified: 16 Mar 2024 20:33
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Colin Ross King
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