Oxygen reduction on Nafion®-bound unpyrolyzed metal macrocyclic complexes

Unpyrolyzed transition-metal macrocyclic complexes were examined for possible use in polymer electrolyte fuel cells (PEFC). Test results show that cobalt complexes generate more H2O2 than iron complexes in oxygen reduction. Cobalt complexes are more stable than iron complexes in an acid electrolyte when bound with Nafion® but high peroxide yields during oxygen reduction make them unsuitable for practical use.