To improve the oxygen reduction reaction(ORR) performance in aproton-exchange membrane fuel cell (PEMFC) cathode with respect tomass activity and durability, a suitable electrocatalyst design strategyis essentially needed. Here, we have prepared a sub-three nm-sizedplatinum (Pt)-cobalt (Co) alloy (Pt3Co)-supportedN-doped microporous 3D graphene (Pt3Co/pNEGF) by usingthe polyol synthesis method. A microwave-assisted synthesis methodwas employed to prepare the catalyst based on the 3D porous carbonsupport with a large pore volume and dense micro-/mesoporous surfaces.The ORR performance of Pt3Co/pNEGF closely matches withthe state-of-the-art commercial Pt/C catalyst in0.1 M HClO4, with a small overpotential of 10 mV. The 3Dmicroporous structure of the N-doped graphene significantly improvesthe mass transport of the reactant and thus the overall ORR performance.As a result of the lower loading of Pt in Pt3Co/pNEGF ascompared to that in Pt/C, the alloy catalyst achieved 1.5 times highermass activity than Pt/C. After 10,000 cycles, the difference in theelectrochemically active surface area (ECSA) and half-wave potential(E (1/2)) of Pt3Co/pNEGF is foundto be 5 m(2) g(Pt) (-1) (Delta ECSA)and 24 mV (Delta E (1/2)), whereas, forPt/C, these values are 9 m(2) g(Pt) (-1) and 32 mV, respectively. Finally, in a realistic perspective, single-celltesting of a membrane electrode assembly (MEA) was made by sandwichingthe Pt3Co/pNEGF-coated gas diffusion layers as the cathodedisplayed a maximum power density of 800 mW cm(-2) under H-2-O-2 feed conditions with aclear indication of helping the system in the mass-transfer region(i.e., the high current dragging condition). The nature of the I-V polarization shows a progressivelylower slope in this region of the polarization plot compared to asimilar system made from its Pt/C counterpart and a significantlyimproved performance throughout the polarization region in the caseof the system made from the Pt3Co/NEGF catalyst (withoutthe microwave treatment) counterpart. These results validate the betterprocess friendliness of Pt3Co/pNEGF as a PEMFC electrode-specificcatalyst owing to its unique texture with 3D architecture and well-definedporosity with better structural endurance.

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