Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.704928
Title: Photocatalytic reforming for hydrogen production using metal/TiO2
Author: Kennedy, Julia
ISNI:       0000 0004 6057 8314
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2016
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Abstract:
The aim of this study was to develop photocatalysts which are active for the production of hydrogen from water and to further understanding of the factors involved in promoting the reaction. Different metals were loaded onto titania and used as photocatalysts for photocatalytic methanol reforming for hydrogen production. The catalysts were characterised using XPS and TPR to understand what produced highly active catalyst. The main factors influencing the catalysts were found to be the ease of reducibility and the work function of the metal used. Pt/TiO2 was the most active of the catalysts tested for photocatalytic methanol reforming. This was attributed to the fact that platinum oxide is easily reduced to platinum metal. Platinum also has a high work function and it was concluded that this property allows better charge transfer and longer charge separation due to a Schottky barrier. Different sacrificial agents with varying numbers of hydroxyl species were tested for photocatalytic hydrogen production. Alcohols, polyols, cyclo-alcohols and carboxylic acids were investigated. A relationship between the number of hydroxyl groups and hydrogen yield was established. The formula suggested for this was 2n+1 = number of moles of hydrogen, where n = number of C-OH groups. The best sacrificial agent was found to be xylitol as it has five C-OH groups and it fully decomposes to carbon dioxide and hydrogen. TiO2 was synthesised using a sol-gel preparation method in an attempt to produce active photocatalysts for photocatalytic methanol reforming for hydrogen production. The phases of TiO2 produced via this method were found to be anatase and brookite. The catalysts with more brookite were found to be more active. The study also highlighted the importance of crystallinity and surface area. The Turkevich method of producing gold nanoparticles was used to produce Au/TiO2. This method produced a more active catalyst than the incipient wetness Au/TiO2 and also emphasized the importance of removal of stabilising agents.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.704928  DOI: Not available
Keywords: QD Chemistry
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