Graphene sheets manipulated the thermal-stability of ultrasmall Pt nanoparticles supported on porous Fe2O3 nanocrystals against sintering

Abstract

Sintering of noble-metal nanoparticles (NPs) presents a major cause for catalyst deactivation as temperature rises. To date, finding simple strategies to develop sinter-resistant catalysts is still a daunting challenge. Herein, we report stable Pt nanoparticles (<3 nm) on porous Fe₂O₃ nanocrystals using wrinkled graphene sheets as a new stabilizing layer to manipulate their thermal-stability against sintering. Such a catalyst system allows the Pt NPs to achieve significant thermal stability against extremely severe thermal treatment up to 750 °C in both inert and oxidative atmosphere and retain strikingly remarkable activity; this is due to rhombohedral Fe₂O₃ nanocrystals ensuring the good dispersibility of Pt NPs across the entire surface, and the distinctive wrinkles on graphene sheets acting as new physical barriers. This study inspires a general approach of developing sinter-resistant catalysts with tunable compositions, to maximize the thermal stability and catalytic activity under harsh conditions.