The development of active and durable proton exchange membrane fuel cell catalysts with high loading (ca. 40%) is critical for the commercialization of hydrogen fuel cells. Herein we report on the synthesis of a novel Pt/C catalyst using a novel bowl-like broken hollow carbon sphere (and N-doped sphere) support (carbon shell thickness ~ 4.6 nm). Highly dispersed Pt nanoparticles (dPt ~ 4 nm) were deposited on both supports and within the carbon shell. The Pt particles in the pores were exposed on both sides of the shell, while the shell porosity ensured pore confinement of the Pt. Both catalysts exhibited high electrochemical surface areas (60–65 m2 g−1) and cycling durability (6000 cycles) that was superior to a commercial benchmark Pt/C catalyst. These studies indicate that high loadings of confined small Pt particles on both sides of thin interconnected carbons can lead to high oxygen reduction reaction activities and durability.
