Synthesis and Characterization of Y-Doped Mesoporous CeO_2 Using A Chemical Precipitation Method

摘要

Using cetyltrimethylammonium bromide (CTAB) as the template agent, cerium nitrate as the cerium resource, yttrium nitrate as the yttrium resource, and ammonium carbonate as the precipitating agent, mesoporous CeO_2 powders doped with different yttrium contents were successfully synthesized using a chemical precipitation method, under an alkalescent condition. Properties of the obtained samples were characterized and analyzed with X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM), infrared (IR) absorbance, and the BET method. For the prepared samples with 20% (molar ratio) Y-doped content, a BET specific surface area of 106. 6 m~2 • g~(-1), with an average pore size of 3.27 nm were obtained. XRD patterns showed that the doped samples were with a cubic fluorite structure. TEM micrographs revealed that the doped samples showed a spherical morphology with a diameter ranging from 20 to 30 nm and a round pore shape. IR results indicated that the Ce-O-Ce vibration intensity decreased as the Y-doped content increased. N_2 adsorption-desorption isotherms showed that the samples possessed typical mesopore characteristics. The average pore size of the samples decreased after mesoporous CeO_2 was doped with yttrium, and the average pore size decreased largely as the Y-doped content increased.