Preparation and electrochemical properties of catalysts based on macrobicyclic d-metal tris-dioximate complexes

Abstract

The use of macrobicyclic tris-dioximate complexes of cobalt, K3[Co(Dmg)3] (where DmgH2=C4H8N2O2), and iron, (BPh)2[Fe(Nx)3] (where NxH2=C6H10N2O2), and the carbon-supported complexes and their pyrolyzates, as catalysts for oxygen reduction was examined utilizing the combination of thermogravimetry, infrared spectroscopy, mass spectrometry and electrochemical techniques. The results have shown that macrobicyclic cobalt complexes adsorbed on the surface of carbon- based synthetic porous polymers have a pronounced catalytic effect on the reduction of molecular oxygen. A reduction in the oxygen overpotential was observed with heat treatment of the catalysts prepared in an inert atmosphere. The optimum pyrolysis temperature for the electrochemically most active catalysts for oxygen reduction was estimated.