A highly ordered Fe–N–C nanoarray as a non-precious oxygen-reduction catalyst for proton exchange membrane fuel cells

A highly ordered Pt-free Fe–N–C catalyst is synthesized through a hydrogen bonding-assisted self-assembly route. The catalyst has a porous structure with an average pore size of 5.5 nm and a large surface area of 416 m2 g−1, making it highly active in oxygen reduction. Cells assembled with the synthesized catalyst perform significantly better than those assembled with amorphous Fe–N–C cathode catalysts. The maximum powers of cells assembled from the highly ordered and amorphous catalysts are 252 and 60 mW cm−2, respectively.

Research highlights▶ A highly ordered Pt-free Fe–N–C catalyst was synthesized through a hydrogen bonding-assisted, self-assembly route. ▶ The synthesized catalyst was found to have a large surface area of 416 m2 g−1 and an average pore size centered at about 5.5 nm. ▶ The enhanced catalyst surface area and unique structure arrangement are beneficial to the electrocatalyst and make the Pt-free catalyst highly active to oxygen reduction. Cells assembled with the highly ordered Fe–N–C catalyst have a performance that is significantly better than that of cells assembled with amorphous Fe–N–C cathode catalysts. ▶ The research also demonstrated that the ordered Pt-free Fe–N–C catalyst is highly conductive and compatible to Nafion electrolyte interfaces, with a RE of 0.2 Ω in the fuel cell operated.