We introduce a new concept for a nanomaterial in terms of both synthesis and properties. The nanomaterial, aggregates of ceria particles around central silver metal (CeO2-Ag), was fabricated by a one-pot selective redox reaction using cerium(III) and silver(I) autocatalyzed by silver metal without the need for surfactants or organic compounds. This unique nanostructure is suitable as a catalyst, in contrast to core shell materials wherein the shell deactivates the catalyst metal. The material was developed to be intimately related to catalytic carbon oxidation.