An elegant 3D-ordered hierarchically porous framework to anchor Pt nanocrystals for durable oxygen reduction reaction.

While Platinum (Pt)-based electrocatalysts have been extensively studied for the oxygen reduction reaction (ORR), improving their durability remains a challenge. One promising approach is to design structure-defined carbon supports that can uniformly immobilize Pt nanocrystals (NCs). In this study, we present an innovative strategy for constructing three-dimensional ordered, hierarchically porous carbon polyhedrons (3D-OHPCs) as an efficient support for immobilizing Pt NCs. We achieved this by template-confined pyrolysis of a zinc-based zeolite imidazolate framework (ZIF-8) grown within the voids of polystyrene templates, followed by carbonizing the native oleylamine ligands on Pt NCs to produce graphitic carbon shells. This hierarchical structure enables the uniform anchorage of Pt NCs, while enhancing facile mass transfer and local accessibility of active sites. The optimal material with graphitic carbon armor shells on the surface of Pt NCs (CA-Pt), named CA-Pt@3D-OHPCs-1600, shows comparable activities to commercial Pt/C catalysts. Furthermore, it can withstand over 30,000 cycles of accelerated durability tests, owing to the protective carbon shells and hierarchically ordered porous carbon supports. Our study presents a promising approach for designing highly efficient and durable electrocatalysts for energy-based applications and beyond.