Activity and degradation study of an Fe-N-C catalyst for ORR in Direct Methanol Fuel Cell (DMFC)

In this work a comprehensive study of the activity and stability of a non-precious metal catalyst of type Fe- N- C in acidic media is reported. The catalyst was prepared from polyaniline, dicyandiamide and iron acetate as precursors. Temperature-dependent rotating-disk electrode experiments were performed to determine the activation energy of the catalyst. Besides, load cycle durability tests with and without the addition of methanol show that there is no additional deactivation caused by methanol addition. In a Direct Methanol Fuel Cell (DMFCs) our catalyst performed similarly good in comparison to other Fe-N-C catalysts. Raman and Mossbauer spectroscopy provide valuable information on the structural composition and chemical changes induced by durability and stability testing of the catalyst. While the maximum power density during DMFC operation decreases by 85%, the qualitative distribution of iron sites might indicate the formation of iron and iron oxide clusters as decomposition product associated with the disintegration of FeN4 sites.