Anti-sintering Pt Particles Confined in Short Ordered Mesoporous Carbon with Rapid Mass Transport for Superior and Robust Oxygen Reduction

摘要

The widespread use of polymer electrolyte membrane fuel cells (PEMFCs) is still hindered by the sluggish activity and poor durability of cathode Pt-based catalysts. Ordered mesoporous carbons are used to inhibit the coarsening and detachment of Pt during oxygen reduction reaction (ORR). However, the long mesopores of OMCs make it hard to utilize the encapsulated Pt particles, leading to a poor ORR activity. Here, we have constructed an OMC with short mesoporous channel as support for confining Pt particles (Pt@s-OMC). Owing to the shortened meso-channels, the proton and oxygen transport is efficiently boosted, resulting an enhanced mass activity (167.1 mA mg(Pt)(-1) at 0.9 V); meanwhile, more metallic Pt and excellent pore structures guarantee the stability of Pt (88 % retention after 4000 cycles). Thus Pt@s-OMC possesses a superior activity and durability simultaneously. This work highlights a distinctive approach to settle the contradiction between high activity and durability, which provides a new insight into ORR catalysts.