A Pt-free catalyst for oxygen reduction reaction based on Fe-N multiwalled carbon nanotube composites

An iron-based non-precious metal (NPM) catalyst was synthesized by chemically coating a polymer containing nitrogen, such as polyaniline (PANI), on multiwalled carbon nanotubes (MWCNTs), followed by iron complexation and heat treatment in a decomposable source of nitrogen (ammonia) at high temperature. Its excellent activities for oxygen reduction reaction (ORR) in both acidic and alkaline media were confirmed by thin film rotating disk electrode technique. Also, durability test was performed in both media. After 20,000 (0.65-1.0 V) potential cycles, the half-wave potential decayed by only 40 mV in 0.1 M HClO4, while in 0.1 M KOH it gained 25 mV. In addition, no activity decay was observed by adding methanol in the acidic solution indicating its excellent tolerance to methanol oxidation.