An iron-based ceramic material is shown to have excellent properties as an electrolyte material for proton exchange membrane in fuel cells. These membranes have comparable conductivity to the NafionRTM membrane with the advantages of lower material costs, and the ability to operate at higher temperatures. Iron oxide nanoparticles (ferroxane) were prepared as precursor materials for membrane fabrication. The structure of ferroxane-derived ceramics was characterized with FTIR, SEM, TEM, and nitrogen adsorption-desorption. Protonic conductivity of the membranes was studied by electrochemical impedance spectroscopy (EIS) to determine their feasibility in fuel cell applications. The conductivity improved as relative humidity increased. Conductivities of sintered samples were significantly higher than those of green bodies. However, sintered samples were less dependent on relative humidity, which would make their performance more reliable than other ceramic materials and Nafion. The protonic conductivity of ferroxane derived ceramics fired at 300°C (ranged from 2.31 to 2.65 x 10-2 S/cm at relative humidities of 58% to 100%). The values are comparable to the conductivities of Nafion membranes.
| Identifer | oai:union.ndltd.org:RICE/oai:scholarship.rice.edu:1911/17836 |
| Date | January 2005 |
| Creators | Tsui, Eliza M. |
| Contributors | Wiesner, Mark R. |
| Source Sets | Rice University |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | 130 p., application/pdf |
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