The supported AuPt alloy nanoparticles (NPs) were designed and successfully synthesized on the surface of 3D ordered macroporous (3DOM) Ce-based oxides by gas bubbling-assisted membrane reduction (GBMR) method. The AuPt alloy NPs were highly dispersed on the pore wall of 3DOM oxides, and their particle sizes are uniformed. 3DOM supports facilitate the contact between reactants and catalysts, and the synergetic effect of the Au-Pt bimetallic alloy particles can obviously increase the content of surface active oxygen species. 3DOM Ce0.8Zr0.2O2-supported AuPt alloy NP catalysts show super catalytic performance for diesel soot oxidation under "loose" contact condition between soot and catalyst. Among the prepared catalysts, 3DOM Au2Pt2/Ce0.8Zr0.2O2 catalyst has the higher catalytic activity for soot oxidation, e.g., its T-10, T-50 and T-90 are 236, 345 and 397 degrees C, respectively. In addition, the second component of Pt in AuPt alloy NPs can remarkably improve the stability of the Au-based catalysts for soot oxidation, which is important for practical application in diesel exhaust after-treatment. The design concept and facile synthesis method of 3DOM oxide-supported AuPt alloy NPs nanocatalysts can be extended to other metal compositions, and could illustrate a promising and efficient way to design active sites for nanocatalysts. (C) 2014 Elsevier B.V. All rights reserved.