Designing Ultrastable Pt/Ceo2-Al2o3 Nanosheet Catalysts Using a Sabatier Principle of Metal-Support Interaction

Designing Rh-free, especially Pt-only, three-way catalysts with improved low-temperature activity/stability is highly desirable. Herein, we demonstrate that ultrastable Pt/CeO2-Al2O3 nanosheet catalysts can be obtained based on a Sabatier principle of metal-support interaction. Tuning the surface coverage of penta-site rich γ-Al2O3 nanosheets (AlNS, weak adhesion to Pt) by CeO2 “nano-islands” (strong adhesion to Pt) can lead to the synthesis of Pt/60 wt.%CeO2-AlNS that have lower light-off temperatures for CO, hydrocarbons, and NO compared to conventional Pt/CeO2 and Pt/Al2O3 catalysts by 100-200 oC and a similar performance with the state-of-the-art Rh-based catalyst. Incorporating CeO2 on the surface of AlNS can retard the sintering of CeO2 and Pt during harsh redox hydrothermal aging. The improved activity/stability of Pt/CeO2-AlNS catalysts can be attributed to tuning of the Pt detachment and migration from and back to the CeO2 nanoislands, respectively, that keeps Pt as nanoclusters on CeO2, the most active species for three-way catalyst applications.