The catalytic properties of the sputtered iron on carbon nanotubes for polymer electrolyte membrane fuel cells

Pure iron metal target was sputtered onto carbon nanotube grown on carbon paper to fabricate iron-based catalysts for the oxygen reduction reaction (ORR). The carbon nanotube-supported Fe-based catalysts have active sites which are believed to include iron cations coordinated by pyridinic nitrogen functionalities between the graphitic sheets. A Fe-based electrocatalyst treated at 950 °C displayed the highest mass activity. The treated sample at lower temperature could not form the Fe/N/CNT sufficiently. On the other hand, the formed Fe/N/CNTs were degraded thermally at higher temperature. Cyclic voltammetry of the Fe-based electrocatalysts showed similar trends with mass activity which is the largest value at 950 °C. Even though the catalytic activity is not comparable with that of Pt/C catalysts yet, sputtered Fe-based electrocatalysts are promising to explore the non-precious metal electrocatalysts.