Hydrothermal Biotemplated Synthesis of Biomorphic Porous CeO2 and Their Catalytic Performance

Biomorphic porous CeO₂ powder was synthesized by the hydrothermal method using stems of clover as biotemplates. Thermogravimetric and differential thermal analysis, X-ray diffraction, N₂ adsorption–desorption, field emission scanning electron microscopy and Fourier transfer infrared spectroscopy were applied to characterize the samples. The oxygen storage/release capacity (OSC) and catalytic oxidation performance of the biomorphic porous CeO₂ for acid magenta were also investigated. Results show that the as-synthesized CeO₂ powders exhibit a cubic phase and have porous structures with pore size ranging from several to dozens of micrometers. The results of N₂ adsorption–desorption measurement suggest that the biomorphic CeO₂ contains a large number of mesopores on the surface of CeO₂ framework; and, the pore diameter is from 15–35 nm. The OSC value of the biomorphic porous CeO₂ is 174.6 μmol O₂/g ceria, which is two-times higher than powdered CeO₂. After catalytic oxidation for 300-min by the biomorphic porous CeO₂, the decolorizing rate of acid magenta is close to 95 %, which is higher than for powdered CeO₂ (64 %).