High pressure nitrogen-infused ultrastable fuel cell catalyst for oxygen reduction reaction

Abstract

The mass activity of a Pt-based catalyst can be sustained throughout the fuel cell vehicle life by optimizing its stability under the conditions of an oxygen reduction reaction (ORR) that drives the cells. Here, we demonstrate improvement in the stability of a readily available PtCo core-shell nanoparticle catalyst over 1 million cycles by maintaining its electrochemical surface area by regulating the amount of nitrogen doped into the nanoparticles. The high pressure nitrogen-infused PtCo/C catalyst exhibited a 2-fold increase in mass activity and a 5-fold increase in durability compared with commercial Pt/C, exhibiting a retention of 80% of the initial mass activity after 180 000 cycles and maintaining the core- shell structure even after 1 000 000 cycles of accelerated stress tests. Synchrotron studies coupled with pair distribution function analysis reveal that inducing a higher amount of nitrogen in core-shell nanoparticles increases the catalyst durability.