Highly durable electrocatalyst with low-loading platinum-cobalt nanoparticles dispersed over single-atom Co-N-Graphene nanofiber for efficient fuel cell

Abstract Development of highly-active, durable and cost-effective oxygen reduction electrocatalyst for proton exchange membrane fuel cell is crucial and greatly desired to enable fuel cell powered vehicles that are competitive with internal combustion engine automobiles. The support’s structure is known to strongly influence the performance of Pt particles. Here, we present a new catalyst containing PtCo core-shell nanoparticle supported over hierarchical tailored porous carbon nanofibers with densely populated single-atomic Co-Nx sites embedded in N-doped graphene. In a fuel cell with a total Pt loading (anode + cathode) of 0.091 mg cm-2, the new catalyst delivered unprecedented mass activity of 2.28 A mgPt-1 at 0.9 ViR-free, Pt utilization of 11.1 kW gPt-1 at 150 kPaabs, and high durability with 80% retention of initial mass activity after 30,000 accelerated-stress-test cycles, significantly higher than that of the state-of-the-art Pt3Co/C. In-situ X-ray absorption spectroscopy revealed structure reversibility of the catalyst during oxygen reduction reaction and indicated that the enhanced activity can be attributed to simultaneous PtCo and Co-Nx contributions.