多孔单晶CeO_2空壳球的制备及其CO催化氧化性能研究

Synthesis of mesocrystal CeO_2 hollow spheres and their catalytic performance on CO oxidation

以水热法成功制备了(110)面暴露的高活性多孔单晶CeO2空壳球催化剂样品,研究了其形成过程并提出了相应的形成机理.通过X射线衍射、透射电镜及低温氮气吸附/脱附等温线对催化剂结构进行了详细的表征,结果表明:该材料具有多孔结构以及较高的比表面积(259 m2/g).该多孔单晶CeO2催化剂在CO氧化转化中显示了较好的催化性能,其催化活性远高于商业化CeO2,这主要归结于其特殊的(110)高能面的暴露以及多孔单晶结构.

The highly active mesocrystal CeO2 hollow spheres with exposed （110） high energy facets were synthesized by hydro- thermal process. We studied the formation process and proposed the formation mechanism. The as-synthesized catalyst was charac- terized by the X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption isotherms. It was found that the mesocrystal CeO2 hollow spheres had porous structure and high specific surface area （259 m2/g）. The catalytic oxidation of CO to CO2 was selected as the model reaction to characterize the performance of the mesocrystal CeO2. The result showed that the meso- crystal CeO2 hollow spheres displayed higher catalytic activity than the commercial CeO2 sample mainly due to their mesocrystal structure, high surface area, the hollow structure, and the exposed （110） high energy facets.