Room temperature interfacial reaction-directed synthesis of hierarchically porous ceria from a water-soluble precursor

Unlike the conventional calcination of cerium precursors at elevated temperature, hierarchically porous ceria was successfully synthesized via an interfacial reaction between the water-soluble cerium sulfate (Ce2(SO4)3) precursor and NaOH in ethanol at room temperature. Neither additional surfactant molecules nor calcination was employed during the whole preparation process. It was found that the as-prepared ceria inherited well the shape and dimensions of the hierarchically flowerlike Ce2(SO4)3 precursor after the interfacial reaction. The concentration of sulfuric acid was demonstrated to play a great role in controlling the precursor's morphology. Compared with ceria derived from direct calcination of the same Ce2(SO4)3 precursor, the one obtained from the interfacial reaction was far more reactive in CO oxidation due to its well-retained hierarchically porous morphology and high surface area. This work is expected to open a new, simple avenue for the synthesis of hollow nanomaterials from water-soluble precursors.