Synthesis of biomorphic hierarchical CeO2 microtube with enhanced catalytic activity

A biomorphic CeO2 microtube with multiple-pore structure was fabricated by using the cotton as biotemplate, through cerium nitrate solution infiltration and thermal decomposition. Field emission scanning electron microscope (FESEM), powder X-ray diffraction (XRD), transmission electron microscope (TEM), N-2 adsorption-desorption isotherms, temperature-programmed reduction (TPR) and CO oxidation were used to characterize the samples. The results indicated that the synthesized products were composed of crystallites with grain size about 9 nm and exhibited a fibrous morphology similar to the original template and possessed a specific surface area (BET) of 62.3 m(2)/g. Compared with the conventional CeO2 particles, the synthesized materials showed a superior catalytic activity for CO oxidation. For the synthesized fibrous CeO2, the CO conversion at 320 degrees C was above 90% and a 100% CO conversion was obtained at 410 degrees C.