Improving the ORR catalytic performance of hollow porous carbon derived from F127 assembled in ethanol-hexane mixture containing Fe³⁺ ion

To reduce the cost of fuel cell oxygen reduction reaction catalysts, the gels of polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO) triblock copolymer (F127) and Fe(NO₃)₃·9H₂O, formed in ethanol-hexane mixture by sol–gel method, were pyrolyzed to prepare the iron-doped carbon-based ORR catalysts. Among all the prepared samples, the Fe2-C, pyrolyzed at 800 ℃ with 0.6 mmol content of Fe(NO₃)₃·9H₂O, possessed highly graphitized structures (I_D/I_G = 0.632), the highest specific surface area (251.3 m²/g) and the best electrochemical performance. Its onset potential and half-wave potential were 0.85 V vs. RHE and 0.71 V vs. RHE in 0.1 M KOH solution, respectively. Meanwhile, Fe2-C also had better stability and methanol tolerance than commercial 20% Pt/C. The results provided a convenient and low-cost method for preparing more efficient ORR catalysts for anion exchange membrane fuel cells.