Thesis
Plasma enhanced metal organic chemical vapor deposition (pemocvd) of catalytic coatings for fuel cell reformers
Washington State University
Master of Science (MS), Washington State University
2003
Handle:
https://hdl.handle.net/2376/158
Abstract
In this experimental work catalytic metals were loaded onto substrates by a plasma-polymerization step followed by a heat treatment step. The substrate, FeCrAlloy, is an alloy of iron, aluminum and chromium primarily with traces of lanthanum group metals. The substrate has a very high thermal conductivity and low coefficient of expansion. Vapors from a catalyst-containing organic precursor are converted to plasma and deposited as a sub-micron film onto the substrate. Both pulsed and steady state RF energy is applied to the plasma. The plasma-polymerized film was then calcined to drive off organic material, leaving behind a catalyst-loaded substrate. The plasma-polymerized organic films and the final heat-treated substrate surface were characterized by scanning electron microscopy (SEM) and impedance spectroscopy. Energy dispersive spectroscopy (EDS) and wavelength dispersive spectroscopy (WDS) were used to detect the presence of the catalyst on the substrate. X-ray diffraction studies revealed that the nature of the coating after the heat treatment was mostly crystalline. Inductively coupled plasma mass spectroscopy (ICP-MS) studies gave the exact amount of the catalyst loaded onto the substrates after plasma deposition and after heat treatment. Overall, this experimental study provides insights into the scope of loading of catalyst(s) onto different substrates using steady-state plasma. Both non-noble metals like nickel, copper, iron, cobalt and noble metals like palladium, platinum when bonded to alumina, zirconia supports forms good catalysts for fuel cell reformers. Hence, several different types of supports were prepared and applied to the metallic substrates. It is believed that after effective loading of the catalyst, controlling the temperature of the heat – treatment step is crucial for both, effective dispersion of the catalyst in the support sub-surface and forming stable catalyst – support bonds. A novel technique of using two organo metallic precursors for developing a composite layered thin film using steady state RF plasma was also developed. This method helped in depositing the catalyst, platinum, while simultaneously developing the catalyst support on the FeCrAlloy substrates by plasma deposition.
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Details
- Title
- Plasma enhanced metal organic chemical vapor deposition (pemocvd) of catalytic coatings for fuel cell reformers
- Creators
- Romit Dhar
- Contributors
- Patrick D. Pedrow (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525127501842
- Language
- English
- Resource Type
- Thesis