Oxygen reduction on polycobaltprotoporphyrin film: II. pH effect and the mechanism of oxygen reduction

The oxygen reduction kinetics on polycobaltprotoporphyrin (PCoPP) film has been examined with the rotating disc electrode technique in O₂-saturated solution of various pH. PCoPP film promotes the oxygen reduction process via two electrons to produce peroxide over wide pH range. When pH value of solution decreases, catalytic activity of PCoPP film increases. Possible catalytic mechanisms have been proposed for oxygen reduction.