COMPARATIVE-STUDY OF THE ELECTROCATALYTIC ACTIVITY OF COBALT PHTHALOCYANINE AND COBALT NAPHTHALOCYANINE FOR THE REDUCTION OF OXYGEN AND THEOXIDATION OF HYDRAZINE

Cobalt phthalocyanine (CoPc) and cobalt naphthalocyanine (CoNPc) exhib it different redox and electronic properties. Redox processes on CoPc are more reversible than on CoNPc. The pH dependence of those processe s is also different for these complexes, which could indicate that in the case of CoNPc, the redox couples observed involve the macrocyclic ligand and not the metal as with CoPc. This seems to explain the diffe rent redox properties and kinetics for O-2 reduction and N2H4 oxidatio n of these two macrocyclics. In this study we compare the electrocatal ytic activity of these two phthalocyanines, adsorbed on glassy carbon, for the electrochemical reduction of O-2 and for the oxidation of hyd razine. (C) 1998 Elsevier Science Ltd. All rights reserved.