On the mechanism of electrocatalytic oxygen reduction at metal chelates: Part III. Metal phthalocyanines

Abstract With the rotating ring disk electrode the kinetics of electrochemical oxygen reduction was investigated at polymer phthalocyanine-covered electrodes. The RRDE allows the amount of H 2 O 2 formed during the reaction to be determined quantitatively. Therefore the reaction mechanism can be deduced. Polymeric phthalocyanines containing Fe, Co and Ni as central metal were investigated. Polymeric phthalocyanines of Fe and Co were compared with the respective monomeric compounds. The activity of polymeric Fe-phthalocyanines prepared under different conditions was characterised. Rate constants for the reduction of oxygen to H 2 O and H 2 O 2 in 1 M KOH are provided and the reaction mechanism in strong alkaline solution is discussed.