| 초록 |
The development of alkaline membrane fuel cells (AMFCs) enables the adoption of non-platinum catalysts, which are intrinsically stable and have an activity similar to platinum in an alkaline environment for the oxygen reduction reaction (ORR). Unlike PEFCs, only a few preliminary results of the AMFCs have been reported about the electrochemical reaction mechanism. In this regard, it is necessary to understand the reaction mechanism by in-situ electrochemical characterization techniques. Electrochemical impedance spectroscopy (EIS) has the capability to distinguish between the influence of various processes, especially when the system involves multi-step reactions. In this respect, EIS and polarization curve were introduced to study the mechanism of AMFCs. MEAs with Pt/C and/or Cu-Fe/C were analyzed by various operation conditions; H2 flow rate, H2 relative humidity, O2 concentration and O2 relative humidity. Different resistances (ohmic, contact, charge transfer and diffusion resistance) from EIS results were compared in detail to understand the mechanism and characteristics in AMFCs. |
