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

Abstract

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.