Electrocatalytic Activity of Macroheterocyclic Complexes in the Molecular Oxygen Electroreduction: A Cyclic Voltammetry Estimate

Abstract

Electrochemical and electrocatalytic properties of differently structured macroheterocyclic complexes (MC) are studied by a cyclic voltammetry method. The potential at half-height of the rising branch of the peak current of the first stage in the oxygen reduction, $E_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{O_2 }$, is used for estimating the electrocatalytic action of complexes. Major structural factors that exert maximum electrocatalytic action on the oxygen reduction are determined by comparing $E_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{O_2 }$ for different MC. The maximum electrocatalytic activity in this reaction in 0.1 M KOH is exhibited by complexes containing cobalt and iron as the central metal atom as well as polymeric compounds and those having electron-donating substituents in the organic ligand.