Anchored and confined Pt nanoparticles in radial mesoporous hollow carbon spheres enhancing oxygen reduction reaction stability.

The employment of different carbon supports during the fabrication of electrocatalysts has a considerable impact on the properties of loaded metal particles and even the stability of catalysts. Here, we present N-doped mesostructured hollow carbon spheres (HCSs) with radial mesoporous shells and a high specific surface area, that were synthesized by a one-pot and surfactant-free method. Pt nanoparticles of around 2 nm size were loaded on the HCS support as a highly stable electrocatalyst by the synergistic effect of nitrogen anchoring and partial pore confinement. The synthesized Pt/HCS catalyst possesses superior ORR activity compared to commercial Pt/C, with a half-wave potential of 0.906 V and mass activity of 0.266 A mg_Pt⁻¹. Remarkably, the mass activity of Pt/HCS only declined by 13% after an accelerated durability test of 30 000 cycles, whereas that of Pt/C dropped by 76%. These results indicate that Pt/HCS will be a promising catalyst for the cathodic oxygen reduction of PEMFCs. [ABSTRACT FROM AUTHOR]