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, N-2 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 N-2 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 mu mol O-2/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 %).