Structure of the catalytic sites in Fe/N/C-catalysts for O-2-reduction in PEM fuel cells
Physical Chemistry Chemical Physics Volume: 14 Issue: 33 Pages: 11673-11688 Published: 2012 Fe-based catalytic sites for the reduction of oxygen in acidic medium have been identified by57Fe Mössbauer spectroscopy of Fe/N/C catalysts containing 0.03 to 1.55 wt% Fe, which were prepared by impregnation of iron acetate on carbon black followed by heat-treatment in NH3 at 950 °C. Four different Fe-species were detected at all iron concentrations: three doublets assigned to molecul