Electrochemical Oxidation of Surface Oxides to Partially Recover the Performance of Non-PGM Catalyst under Fuel Cell Operation

Abstract

An iron based metal-nitrogen-carbon (MNC) type oxygen reduction reaction catalyst was tested for in-situ polarization performance and durability. High open circuit voltage (OCV) of ~0.97 V and high activities were observed. Current density around 750 mA/cm2 was obtained at 0.6 ViR-free/RHE and volumetric current density of 31 A/cm3 was obtained at 0.8 ViR-free. A significant decrease in polarization after start-stop durability test was observed for this catalyst. An attempt was made to recover the in-situ performance after start-stop durability test by running the fuel cell at steady state current density. Partial performance recovery was achieved from the significantly degraded MNC based membrane electrode assembly (MEA). However, performance could not be recovered indefinitely due to eventual carbon loss.