Small-sized Pt particles on mesoporous hollow carbon spheres for highly stable oxygen reduction reaction

Mesoporous hollow carbon spheres (HCSs) are prepared using glucose as carbon source and solid core mesoporous shell silica spheres (SCMSSs) as templates. Pt particles are then loaded on the HCSs as electrocatalyst and used for oxygen reduction reaction (ORR) in acidic media. Physical measurements display that the HCSs have high surface area (1163 m2 g−1), large pore volume (2.8 cm3 g−1) and mesoporous structure (9.8 nm in diameter), which are favorable for uniform dispersion and stable loading of small-sized Pt particles, and efficiently improve the mass transfer in catalytic reactions. Cyclic voltammogram measurements show that the mass current density on Pt/HCS electrocatalyst (192.2mAmgPt−1) is 1.7 times as high as that of commercial Pt/C (TKK) for ORR. Furthermore, the mesopores of HCSs give Pt/HCS more electrocatalytic stability due to stronger physical interaction force.