Highly Durable Fuel Cell Catalysts Using Crosslinkable Block Copolymer-Based Carbon Supports with Ultralow Pt Loadings

Minimizing the use of Pt catalysts in proton exchange membrane fuel cells (PEMFC) is important, considering its high price and scarcity. Herein, we demonstrate novel catalysts for PEMFCs with exceptionally high mass activity and durability, in which block copolymer-based carbon supports are loaded with an ultra-small amount of Pt. The mass activity measured after 30,000 cycles of single cell tests was 0.81 A mg-1Pt at 0.9 V, which is the highest performance reported to date. The newly developed catalyst yielded nearly the same power density as that of the commercial Pt/C, even with 1/20 of Pt usage. The carbon supports were prepared by carbonizing crosslinked domain of block copolymer particles selectively, resulting mesoporous carbon particles with ~25 nm pores. When Pt was deposited, thin carbon shells were formed encapsulating PtFe nanoparticles, catalyzing oxygen reduction reaction efficiently with high durability.