• • Pt1-MoS2/hNCNC achieves an overpotential of 11 mV at 10 mA cm−2 and a mass activity of 5.6 A mgPt−1 at −20 mV in 0.5 M H2SO4, surpassing commercial Pt/C and enabling significant Pt loading reduction in PEMWE cathodes.
• • In a PEMWE MEA with an ultralow Pt loading of 40 μg Pt cm−2, the catalyst delivers 0.5 A cm−2 at 1.55 V, 1.0 A cm−2 at 1.66 V, and 2.0 A cm−2 at 1.88 V, demonstrating industrial-level current densities at an order of magnitude lower Pt loading than commercial PEMWE.
• • The MEA exhibits a mass activity of 31.3 A mgPt−1 at 1.7 V, exceeding the 25.0 A mgPt−1 of a commercial 20 wt% Pt/C-based MEA, which translates to higher Pt utilization efficiency and potential cost reduction.
• • Durability testing at 1 A cm−2 shows a degradation rate of 40 μV h−1 over 500 h, outperforming Pt1/hNCNC (90 μV h−1) and commercial Pt/C (44 μV h−1), addressing the critical stability bottleneck for SACs in PEMWE.