High Pressure Nitrogen-Infused Ultrastable Fuel Cell Catalyst for Oxygen Reduction Reaction

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.