| 초록 |
Highly ordered mesoporous cerium dioxide (meso-CeO2) was successfully synthesized using a facile solvent-free infiltration method from a mesoporous silica template, KIT-6. The meso-CeO2 material, thus obtained, exhibited well-defined mesostructure and high surface area (153 m2 g-1). The physicochemical properties of meso-CeO2 material and Pd-supported on meso-CeO2 (Pd/meso-CeO2) were characterized by electron microscopy, X-ray diffraction, N2 adsorption-desorption, CO-TPD, H2-TPR, and O2-TPO. The catalytic activity of the Pd/meso-CeO2 catalyst for CO oxidation was compared to those of Pd/CeO2 catalysts which were prepared by using nanocrystalline CeO2 (nano-CeO2) and bulk-CeO2 as the supports. The Pd/meso-CeO2 catalyst exhibited higher catalytic activity (than other catalysts (T100 = 180 oC for Pd/nano-CeO2 and T100 = 190 oC for Pd/bulk-CeO2). Moreover, H2-pretreatment of the Pd/meso-CeO2 and Pd/nano-CeO2 catalysts resulted in remarkable increase in catalytic activity(T100 = 52 oC and T100 = 100 oC, respectively),where as Pd/bulk-CeO2 catalyst showed slight increase in catalytic activity. |
