Heat-treated mu-oxo-iron(III) tetramethoxy phenyl porphyrin (Fe-TMPP)(2)O and iron(III) tetramethoxy phenyl porphyrin (FeTMPP-Cl) as well as iron(III) octaethyl porphyrin (FeOEP-Cl) adsorbed on high-area carbons such as deashed and un-deashed RE carbon (Calgon) and Black Pearls-2000 (Cabot) have been found to exhibit stable and very high oxygen reduction rates. Experiments done over a period of 24 h showed no performance degradation. Measured performances were very similar to supported platinum (E-Tek), when tested in 85% H3PO4-equilibrated Nafion(R) 117 membrane at 125 degrees C and hydrated-Nafion(R) membrane at 60 degrees C in a minifuel cell. The macrocycle cathodes are insensitive to the presence of methanol whereas the platinum cathodes are very sensitive and show degradation in the oxygen reduction performance.