Active and stable Pt-Ceria nanowires@silica shell catalyst: Design, formation mechanism and total oxidation of CO and toluene

Cerium oxide is one of the most important rare earth metal oxides in catalysis, however, the sintering problem of noble metals and CeO₂ at higher temperature (e.g., >700 °C) is still unresolved. Herein, Pt nanoparticles self-assembled on ultra-thin CeO₂ nanowires (NWs) and then confined inside a thermally robust porous silica shell (Pt-CeO₂NW@SiO₂) were introduced. The thickness of CeO₂ NWs was just ˜2.0 nm. Moreover, Pt-CeO₂ NW@SiO₂ showed significantly enhanced catalytic performances for total oxidation of CO and toluene. The increased catalytic properties are attributed to the strong metal-support interaction effect between Pt and CeO₂ NWs at sub-nanoscale. Most importantly, the special core-shell structure also affords excellent sintering resistance retention up to 700 °C for 100 h, due to the guarding effect of porous silica shell. Finally, the formation mechanism of Pt-CeO₂ NW@SiO₂ was investigated in detail. Current strategy should inspire many rational designs of rare-earth metal-based nanocatalysts for real-world catalysts.