Developing a highly efficient and durable proton exchange membrane fuel cell (PEMFC) using a low amount of platinum is essential for minimizing the total cost. Herein, the development of high-performance PEMFC catalysts is demonstrated using ultra-low Pt loaded (1 wt%) porous carbon with controlled channel diameters (D-ch = 13-63 nm), produced from block copolymer particles. The single cell based on the catalyst with the largest D-ch of 63 nm yields an initial maximum power density of 1230 mW cm(-2) and high durability showing 1120 mW cm(-2) after 30 000 cycles under H-2/O-2 flow, which outperforms those of commercial Pt/C catalysts despite 1/20 Pt usage. Furthermore, the catalyst shows outstanding performance with 51 kW per gram of Pt (kW gPt-1) after 30 000 cycles in H-2/air flow, which is the highest performance reported to date. The channel structure and large D-ch of the porous particles are the keys to enhancing the power density by improving the proton and mass transport.