Confining Pt nanoparticles in porous carbon structures for achieving durable electrochemical performance.

Carbon-supported Pt catalysts have been widely employed as electrocatalysts for energy storage/conversion applications, but have encountered challenging instability issues. In this work, we investigated the degradation behaviors of pore-confined and surface-located Pt nanocatalysts, employing hollow porous carbon spheres with precisely controlled structure as catalyst supports. It is found that by uniformly confining Pt nanoparticles in porous carbon structures, remarkably improved stability and long-term performance of Pt electrocatalysts can be achieved. The nanopore-confined Pt exhibits high retention ratios of both ECSA (54%) and electrocatalytic activity after accelerated degradation tests (ADTs), both of which are almost two times higher than those of the surface-located ones. TEM analysis of the degraded electrocatalysts further revealed that the pore-confinement effect can significantly suppress the Pt degradation processes, including particle migration/agglomeration and detachment from the carbon support.