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

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, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$E_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{O_2 } $$ \end{document}, 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 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$E_{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}}^{O_2 } $$ \end{document} 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.