Ti-doped Pt3Fe intermetallic nanoalloys on TiN–FeNC aerogel: Highly active and non-degradable oxygen reduction electrocatalyst in fuel cells

High energy density makes proton exchange membrane fuel cells (PEMFCs) prime candidates for clean power in heavy-duty vehicles (HDVs); yet the extended life of HDVs imposes stringent demands on the durability of the oxygen reduction reaction (ORR) catalyst. Herein, a TiN hybridized FeNC aerogel is designed as a multifunctional support to synthesize a highly active and stable ORR catalyst. The unique design features: (i) TiN and Fe–N x moieties acting as dual anchors and precursors, enabling anti-sintering formation of Ti–doped Pt 3 Fe intermetallic nanoparticles at 1000 °C; (ii) Ti doping increasing the vacancy formation energy of Fe and Pt, thereby suppressing metal dissolution; (iii) TiN scavenging peroxide intermediates to mitigate the Fenton reaction-induced carbon corrosion; and (iv) an interconnected aerogel structure facilitating efficient mass transport. The resulting catalyst achieves a remarkable peak power density of 2.25 W/cm 2 at an ultralow Pt loading of 0.075 mg Pt /cm 2 with no performance loss after 30,000 cycles. It also retains 100% mass activity after 1,100,000 RDE cycles, and maintains structural integrity with 1.85 W/cm 2 peak power density after 150,000 PEMFC cycles, where a minor 30 mV voltage loss at 0.80 A/cm 2 is attributed to ionomer degradation. This multi-factorial stabilization strategy unlocks a pathway to ultradurable PEMFCs for HDVs at ultralow Pt loadings. • Ti-doped Pt 3 Fe intermetallic on TiN–FeNC aerogel achieves a record 2.25 W/cm 2 at 0.075 mg pt /cm 2 Pt loading. • Ti doping suppresses metal dissolution and TiN scavenges radicals, yielding