In this work, novel three-dimensional (3D) navicular ceria micro/nanocomposite architecture with multi-layered structure was synthesized for the first time via solution reaction followed by a simple hydrothermal treatment in the presence of lysozyme. During the synthesis procedure, a 3D navicular ceria precursor (Ce2O(CO3)(2)center dot H2O) with multi-layered structure was obtained after hydrothermal treatment at 100 degrees C for 10 h. Ceria with the same morphology can be obtained after thermal decomposition of this Ce2O(CO3)(2)center dot H2O precursor. Structural properties of the products were characterized by XRD,TG-DTA, FT-IR, SEM, TEM, and N-2-sorption techniques. Then a possible layer-by-layer electrostatic self-assembled growth mechanism was proposed for the formation of this 3D navicular architecture based on the experimental results and detail analysis of the evolution process of ceria precursors. Furthermore, a mold reaction of the catalytic oxidation of CO was conducted on the as-obtained CeO2 and gold supported catalyst, both showed excellent activity and durability for CO conversion. (C) 2009 Elsevier B.V. All rights reserved.