Highly durable carbon-encapsulated Pt nanoparticles for low-Pt-loading fuel cells

Proton exchange membrane fuel cells (PEMFCs) hold significant promise as clean energy conversion devices; however, their widespread adoption is constrained by the rapid degradation of catalysts under operating conditions. Herein, we report a convenient and scalable approach that significantly enhances catalyst durability via controlled carbon encapsulation through methane decomposition. The optimized Pt@C/XC540 retained 62.3 % of its initial mass activity after a 30,000-cycle accelerated durability test (ADT), outperforming the uncoated Pt/XC (36.5 %), and surpassing the 60 % retention target set by the U.S. Department of Energy (DOE). When this strategy was extended to catalysts loaded on porous carbon support, Pt@C/BP2K delivered a rated power of 15.1 W/mg_PGM. More importantly, the Pt@C/BP2K catalyst exhibited outstanding stability, retaining 94.7 % of its rated power after 30,000-cycle ADT, markedly outperforming commercial Pt/C (33.1 %) and uncoated Pt/BP2K (87.4 %). And, its voltage loss at 0.8 A/cm² was only 1.7 mV, less than 5.7 % of the voltage loss DOE target (30 mV), demonstrating the superior stability of Pt@C/BP2K. Transmission electron microscopy showed that pore confinement and carbon encapsulation effectively suppress Pt nanoparticle coarsening. By converting methane-derived carbon into a protective layer, this strategy produces highly durable Pt catalysts without sacrificing performance, offering a cost-effective route for next-generation electrochemical energy conversion technologies.