Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.585237
Title: Oxidative destruction of volatile organic compounds using heterogeneous catalysis
Author: Sellick, David Richard
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2011
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Abstract:
The preparation, testing and characterisation of catalysts for the total oxidation of two volatile organic compounds (VOCs) have been studied. These two VOCs were naphthalene and propane. Naphthalene was the main focus of this study. CeZrC>2 with varied Ce:Zr ratios and preparation methods was investigated for the total oxidation of naphthalene. These preparation methods were all precipitation methods using different precipitating agents (urea, sodium carbonate and supercritical CO2). Zr contents as low as 1 molar percent enhanced activity for both urea and sodium carbonate precipitated catalysts compared to CeC>2. A supercritical analogue was found to be less active. Pt/SiC>2 as a catalyst for naphthalene total oxidation was studied with a view to optimise an existing impregnation technique. A Pt loading of 2.5wt% with a calcination regime of 550 °C for 12h in static air with a ramp rate of 5 °C/min was found to be optimal. These preparation conditions were found to increase the proportion of metallic Pt which was found to exist as large crystallites with low dispersion. Other catalyst features were probed in this study. The type of silica used as a support was changed to novel hollow sphere silica then nanopore silica but no improvement in activity was found. Pt was then substituted for Pd which again did not improve activity. It was found that the Pd existed as Pd oxide hence Pd oxide is not as active for naphthalene oxidation as metallic Pt. The preparation of impregnated catalysts using non-aqueous solvents on so-called 'hydrophobic' materials was also investigated. These were tested for both naphthalene and propane total oxidation. It was found that Pt and Pd based catalysts afforded the most active catalysts. Several supports were studied which interacted with the impregnated metals in different ways. This affected the nature of the impregnated metals and therefore the activities of these catalysts. Some of the more active catalysts used supports that were of a low surface area. A high surface area SnO2 support was produced and impregnated with Pd. The high surface area SnO2 was found to be more active than the original Pd/SnO2 catalyst for propane total oxidation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.585237  DOI: Not available
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