Oxygen-Reduction Reaction of Pyromellitimide-Bridged Polyphthalocyanine Fe(II)

The activity of a pyromellitimide-bridged polyphthalocyanine Fe(II) catalyst for O-2 reduction is studied by density functional theory calculations. Three model molecules with different polymerization degrees are designed to investigate O-2-reduction electrocatalytic reactivity. The molecular and electronic structures of the models and their O-2-complexes are optimized with BP86 functional and SVP basis sets. The central Fe atom in the catalyst binds O-2 by a double bond followed by a charge transfer to reduce O-2. This study indicates that the catalyst has potential for O-2-reduction electrocatalytic activity. The calculated frontier molecular orbitals and stabilities of the O-2-complexes demonstrate that catalysts with a higher polymerization degree and stronger electron-withdrawing groups will have higher activities for O-2 reduction. O-2-reduction activity of the catalyst is achieved via an electrocatalytic cycle.