Abstract
We have examined the electrocatalytic activity of iron phthalocyanine (FePc) and perchlorinated iron phthalocyanine 16(Cl)FePc for the oxygen reduction reaction (ORR) in alkaline medium with the two molecules either adsorbed on the external surface of singlewall carbon nanotubes (SWCNT) or covalently anchored via an axial pyridine ligand on pyridinefunctionalized singlewall carbon nanotubes (pySWCNT). Regardless of the particular phthalocyanine type, the ORR activity is higher when the substrate is pySWCNT rather than SWCNT. The Tafel slopes for ORR are very similar for the two Fe macrocyclic complexes attached to SWCNTs in the two different configurations, suggesting a common ratedetermining step for the ORR for all four catalysts. It is also observed