Core/Shell‐Structured Carbon Support Boosting Fuel Cell Durability

To enhance the lifetime of proton exchange membrane fuel cells, developing highly durable platinum-based cathode catalysts is essential. While two degradation pathways for the cathode catalyst-carbon corrosion and electrocatalyst (platinum nanoparticles) coarsening-have been identified, current approaches to enhance its durability are limited to addressing individual degradation pathways. Herein, the study develops a core/shell-structured carbon support that is designed to afford cathode catalysts capable of simultaneously inhibiting carbon corrosion and electrocatalyst coarsening. The core/shell structure is distinguished by its bifunctional nature: the core is made of highly graphitized carbon tailored to build a robust carbon skeleton, and the shell comprises heteroatom-doped amorphous carbon engineered to prevent electrocatalyst coarsening by chemical/physical anchoring of platinum nanoparticles. Thanks to this elaborate design, the catalyst surpasses the durability targets for carbon supports and electrocatalysts set by the U.S. Department of Energy, as supported by the achieved durability metrics after the square-wave/triangle-wave accelerated stress tests: electrochemical surface area loss at 13%/3%, mass activity loss at 27%/17%, and voltage loss of 29 mV (at 0.8 A cm^{- 2})/4 mV (at 1.5 A cm^{- 2}).