Sparsely Dispersed CeO _<i>x</i> -Stabilized Pt Nanoparticles Overcome Pt Loading–Durability Trade-Off for Highly Durable Heavy-Duty Fuel Cells

Proton-exchange-membrane fuel cells (PEMFCs) are clean and sustainable mobile power sources for transportation. Recently, their deployment in heavy-duty vehicles (HDVs) has attracted growing interest owing to their high energy scalability and lower infrastructure requirements. However, to meet the stringent requirements for efficiency and long-term durability for HDV applications, PEMFCs typically employ a relatively high platinum group metal (PGM) loading (>0.2 mg_PGM/cm²). This elevated PGM loading significantly increases the stack and system costs, surpassing the U.S. Department of Energy (DOE) target of $60/kW for commercial viability. Reducing PGM loading while maintaining performance and durability remains a central challenge for HDV fuel cells. Here we exploit metal oxide-Pt interactions and utilize the strong CeO_<i>x</i>-Pt interaction to design a CeO_<i>x</i>@Pt catalyst structure with exceptional durability. At a low total PGM loading (0.1 mg_PGM/cm²), the CeO_<i>x</i>@Pt/C catalyst demonstrates high fuel cell performance (8.8 kW/g_PGM) and stability (power retention >90%) after the challenging HDV durability testing (90,000 accelerated-stress-test cycles). With the CeO_<i>x</i>@Pt/C catalyst, we showcase over 70% reduction in Pt cost from the M2FCT target (to $9/kW), highlighting its promising potential for enabling stable and cost-effective fuel cell systems for heavy-duty applications.