The University of Southampton
University of Southampton Institutional Repository

Oxygen sensing and oxide formation: Optimisation and novel X-ray studies

Oxygen sensing and oxide formation: Optimisation and novel X-ray studies
Oxygen sensing and oxide formation: Optimisation and novel X-ray studies
Platinum remains vital for the use of electrochemical devices, therefore, understanding of the reactions which occur at the platinum-solution interface is paramount in continuing to improve gas sensors, as well as fuel cells and electrolysers. The following body of work uses a number of electrochemical techniques and X-ray spectroscopies to investigate the surface processes of platinum in acidic media.

The pH range over which the electrochemical behaviour can be accurately modelled by the Nernst equation, has been extended into highly acidic solutions by employing the Hammett acidity function (H0) in place of pH when working below pH 1. Sulfuric acid and perchloric acid have been investigated. Both the hydrogen region and oxide formation region have been studied, and the comparison between these two potential regions by cyclic voltammetry has produced a method for electrolyte concentration measurements.

A variety of X-ray spectroscopies have been used to provide additional understanding of the oxide formation process on platinum. Conventional X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) have presented a baseline for High Energy Resolution Fluorescence Detection (HERFD)-XANES, which offers higher spectral resolution, and Energy Dispersive EXAFS (EDE), which can measure on much smaller time scales. The surface oxidation and reduction of platinum nanoparticles will be discussed.

Additionally, a statistically designed set of experiments have been presented, investigating five parameters in an industrial gas sensor electrode manufacturing process. Both sensor output measurements and lab based techniques were employed to characterise the electrodes. It was shown that the electrode loading could be reduced without affecting the sensors initial performance, so cheaper electrodes can be used.
University of Southampton
Leach, Andrew, Stephen
eb2fee87-ab58-4a28-9319-529de90d1708
Leach, Andrew, Stephen
eb2fee87-ab58-4a28-9319-529de90d1708
Russell, Andrea
b6b7c748-efc1-4d5d-8a7a-8e4b69396169

Leach, Andrew, Stephen (2019) Oxygen sensing and oxide formation: Optimisation and novel X-ray studies. University of Southampton, Doctoral Thesis, 157pp.

Record type: Thesis (Doctoral)

Abstract

Platinum remains vital for the use of electrochemical devices, therefore, understanding of the reactions which occur at the platinum-solution interface is paramount in continuing to improve gas sensors, as well as fuel cells and electrolysers. The following body of work uses a number of electrochemical techniques and X-ray spectroscopies to investigate the surface processes of platinum in acidic media.

The pH range over which the electrochemical behaviour can be accurately modelled by the Nernst equation, has been extended into highly acidic solutions by employing the Hammett acidity function (H0) in place of pH when working below pH 1. Sulfuric acid and perchloric acid have been investigated. Both the hydrogen region and oxide formation region have been studied, and the comparison between these two potential regions by cyclic voltammetry has produced a method for electrolyte concentration measurements.

A variety of X-ray spectroscopies have been used to provide additional understanding of the oxide formation process on platinum. Conventional X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) have presented a baseline for High Energy Resolution Fluorescence Detection (HERFD)-XANES, which offers higher spectral resolution, and Energy Dispersive EXAFS (EDE), which can measure on much smaller time scales. The surface oxidation and reduction of platinum nanoparticles will be discussed.

Additionally, a statistically designed set of experiments have been presented, investigating five parameters in an industrial gas sensor electrode manufacturing process. Both sensor output measurements and lab based techniques were employed to characterise the electrodes. It was shown that the electrode loading could be reduced without affecting the sensors initial performance, so cheaper electrodes can be used.

Text
Leach Final Thesis for Award - Version of Record
Restricted to Repository staff only until 30 June 2021.
Available under License University of Southampton Thesis Licence.

More information

Published date: May 2019

Identifiers

Local EPrints ID: 433180
URI: http://eprints.soton.ac.uk/id/eprint/433180
PURE UUID: 1d1060cb-1ab9-4862-b6d1-53d9fff087e5
ORCID for Andrea Russell: ORCID iD orcid.org/0000-0002-8382-6443

Catalogue record

Date deposited: 09 Aug 2019 16:30
Last modified: 10 Aug 2019 00:37

Export record

Contributors

Author: Andrew, Stephen Leach
Thesis advisor: Andrea Russell ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×