pH-effect on oxygen reduction activity of Fe-based electro-catalysts
Recently, our group reported on an innovative synthesis of Fe/N/C-catalysts that considerably increased their activity for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). This work investigates the ORR-activity in 0.1 M KOH and 0.1 M HClO4 of one such new Fe/N/C-catalyst prepared by ball-milling and compares it to that of a former Fe/N/C-catalyst prepared by impregnation and to that of 46 wt% Pt/C.
At pH 13, the volumetric activities at 0.9 V vs. RHE of the ball-milling Fe/N/C-catalyst, the impregnation Fe/N/C-catalyst and 46 wt% Pt/C are 3.2, 0.3 and 14.8 A cm−3, respectively. The ball-milling Fe/N/C-catalyst is promising for alkaline fuel cells.