Designing ultrastable Pt/CeO2-Al2O3 nanosheet catalysts for three-way catalysts applications

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 gamma-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 degrees C 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 during harsh redox hydrothermal aging, associate with the strong interaction between CeO2 nano-island and penta-site rich gamma-Al2O3 nanosheets. Moreover, 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 nano-islands, respectively, that keeps Pt as nanoclusters on CeO2, the most active species for three-way catalyst applications.

Automated summary

By tuning the surface coverage of γ-Al2O3 nanosheets, ultrastable Pt/CeO2-Al2O3 nanosheet catalysts with improved low-temperature activity and stability were successfully synthesized based on the Sabatier principle of metal-support interaction.