Improved durability of Pt catalyst supported on N-doped mesoporous graphitized carbon for oxygen reduction reaction in polymer electrolyte membrane fuel cells

N-doped mesoporous graphitized carbon (NMGC) was prepared by the pyrolysis of chelating complex adsorbed on carbon. The NMGC shows a higher degree of graphitization than carbon black as evidenced by the change of specific surface area, interlayer spacing, and ID/IG value. The stable quaternary nitrogen type is dominantly observed in the NMGC incorporated with Fe (NMGC-Fe). Pt particles are well-distributed on the NMGC-Fe in the range of 2-3 nm. The Pt/NMGC-Fe catalyst shows remarkably improved durability after 30,000 potential cycles between 0.6 and 1.0 V. The maximum power density and the potential loss of Pt/NMGC-Fe catalyst decrease by 26% and 83 mV at 600 mA cm−2. The commercial Pt/C catalyst shows the very poor durability of 52% loss of maximum power density and zero potential at 600 mA cm−2. The electrochemical surface area of Pt/NMGC-Fe catalyst is more stable than the commercial Pt/C catalyst. The interaction between Pt and NMGC-Fe contributes strongly to the observed high durability under practical operating conditions.

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