Non-PGM membrane electrode assemblies: Optimization for performance

The performance of non-platinum group metals (non-PGM) iron-nitrogen-carbon (Fe-N-C) based cathode in fuel cell operation conditions was studied. The effect of Nafion to catalyst ratio as well as carbon additives on the activity was studied. It was found that ionomer plays a key role in proton and water transport within the MEA. To compensate intrinsic low electronic conductivity of Fe-N-C materials additional carbons such as Vulcan XC72R, Ketjen Black 600 EC, and carbon nanotubes (CNTs) were added to MEA inks. X-ray Phototelectron Spectroscopy studied the effect of these carbon additives on chemical composition of catalysts. It was determined that inks with 35 wt% of Nafion ionomer resulted in the optimal performance of the Fe-N-C cathode catalyst in the air.