Multifunctional catalysts of three-dimensionally ordered macroporous oxide-supported Au@Pt core–shell nanoparticles with high catalytic activity and stability for soot oxidation

Abstract

Supported Au@Pt core–shell nanoparticles (NPs) were successfully synthesized on three-dimensionally ordered macroporous (3DOM) oxides by a one-step gas bubbling-assisted membrane reduction (GBMR) method. The Au@Pt core–shell NPs were highly dispersed on the pore wall of oxides and the Pt shell was obtained by direct epitaxial overgrowth on the surface of the Au core. The multifunctional nanocatalysts were used for diesel soot oxidation. 3DOM structure facilitates the contact between soot particles and catalysts, and the synergetic effect of the Au core and Pt shell significantly increases the surface concentration of active O2− species. 3DOM Ce0.8Zr0.2O2-supported Au@Pt core–shell NP catalyst is one of the best catalysts reported so far for soot oxidation under “loose” contact between soot and catalyst. The stability of the Au-based catalysts for soot oxidation is also improved due to the formation of an Au@Pt core–shell structure.