Doped graphene/carbon black hybrid catalyst giving enhanced oxygen reduction reaction activity with high resistance to corrosion in proton exchange membrane fuel cells

TL;DR

This study develops a nitrogen-doped graphene/carbon black hybrid catalyst that significantly enhances oxygen reduction reaction activity, improves fuel cell performance, and exhibits high resistance to corrosion compared to commercial catalysts.

Contribution

The paper introduces a novel nitrogen doping strategy linking platinum with graphene/carbon black supports, leading to improved catalyst activity and durability in proton exchange membrane fuel cells.

Findings

Achieved 1.55 times higher power density than commercial Pt/C.

Reduced catalyst decay to 10 mV after 30k cycles, surpassing DOE targets.

Maintained 78% of initial power density after 5k cycles, indicating high stability.

Abstract

Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum-nitrogen and carbon-nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black (the ratio graphene/carbon black=2/3) hybrid support materials achieved the average size of platinum nanoparticles with (4.88 +/- 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm-2 at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm-2 after 30k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy (<30 mV). Meanwhile, Pt/NrEGO2-CB3 remains 78% of initial power density at 1.5 A cm-2 after 5k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.