Dokument: The effect of temperature, water vapor and thermal activation on Pt/TiO2/Ti electromotive force cells
| Titel: | The effect of temperature, water vapor and thermal activation on Pt/TiO2/Ti electromotive force cells | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=40361 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20161115-115640-4 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Cakabay, Ömer [Autor] | |||||||
| Dateien: |
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| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 530 Physik | |||||||
| Beschreibung: | In this thesis, the effects of temperature, water vapor, and thermal activity on Pt/TiO2/Ti electromotive force (emf) cells are studied using the microstructural characteristics (SEM, AFM, XPS and Raman spectroscopy), microcalorimetry, current voltage characteristics and electrochemical impedance spectroscopy. Titanium dioxide layers were produced via a plasma electrolytic oxidation process and Pt coating was applied using a pasting process.
The results confirmed the existence of significant effects of temperature, water vapor and thermal activation on Pt/TiO2/Ti emf cells: i) Upon exposure to a hydrogen-in-air mixture, constant values of current densities up to 25 mA/cm2 can be generated as long as the temperature is maintained at around room temperature via a suitable dissipation of the catalytically generated heat. If this condition is not met (for example, if the temperature rises to 50 °C) the generated current breaks down completely. ii) It was found that adding water vapor to the hydrogen-in-air mixture not only reduces the effects of emf generation, but also reduces the catalytic oxidation of hydrogen on Pt. iii) Samples stored in ambient air undergo an aging process that decreases the observed emf effect and current density in hydrogen-in-air mixtures. A short heating process (“flashing”) in air prior to operation restores the aged samples to their initial active state. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Physik » Physik der kondensierten Materie | |||||||
| Dokument erstellt am: | 15.11.2016 | |||||||
| Dateien geändert am: | 15.11.2016 | |||||||
| Promotionsantrag am: | 20.07.2016 | |||||||
| Datum der Promotion: | 06.10.2016 |
