Synthesis of cerium-doped MCM-48 molecular sieves and its catalytic performance for selective oxidation of cyclohexane  

作　　者：詹望成 卢冠忠 郭杨龙 郭耘 王艳芹 王筠松 张志刚 刘晓晖 

机构地区：[1]Lab for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology

出　　处：《Journal of Rare Earths》2008年第4期515-522,共8页稀土学报（英文版）

基　　金：the National Basic Research Program of China (2004CB719500);the Commission of Science and Technology of Shanghai Municipality (06DJ14006);Shanghai Municipal Education Commission (2008CG35)

摘　　要：Cerium-doped MCM-48 molecular sieves were synthesized hydrothermally and characterized by X-ray diffraction, nitrogen adsorption, transmission electron microscope, FT-IR spectroscopy, UV-visible spectroscopy, and Raman spectroscopy. The results showed that all the samples held the structure of MCM-48, and Ce could enter the framework of MCM-48. However, when Ce/Si molar ratio in the sampies was high （0.04 or 0.059）, there were CeO2 crystallites as secondary phase in the extraframework of MCM-48. Ce-doped MCM-48 was a very efficient catalyst for the oxidation of cyclohexane in a solvent-free system with oxygen as an oxidant. In the conditions of 0.5 MPa 02 and 413 K for 5 h, the conversion of cyclohexane was 8.1% over Ce-MCM-48-0.02, the total selectivity of cyclohexanol and cyclohaxnone was 98.7%. With an increase of Ce content, the conversion of cyclohexane and the selectivity to cyclohexanol decreased somewhat, but the selectivity to cyclohexanone increased.Cerium-doped MCM-48 molecular sieves were synthesized hydrothermally and characterized by X-ray diffraction, nitrogen adsorption, transmission electron microscope, FT-IR spectroscopy, UV-visible spectroscopy, and Raman spectroscopy. The results showed that all the samples held the structure of MCM-48, and Ce could enter the framework of MCM-48. However, when Ce/Si molar ratio in the sampies was high （0.04 or 0.059）, there were CeO2 crystallites as secondary phase in the extraframework of MCM-48. Ce-doped MCM-48 was a very efficient catalyst for the oxidation of cyclohexane in a solvent-free system with oxygen as an oxidant. In the conditions of 0.5 MPa 02 and 413 K for 5 h, the conversion of cyclohexane was 8.1% over Ce-MCM-48-0.02, the total selectivity of cyclohexanol and cyclohaxnone was 98.7%. With an increase of Ce content, the conversion of cyclohexane and the selectivity to cyclohexanol decreased somewhat, but the selectivity to cyclohexanone increased.

关 键 词：Ce-doped MCM-48 synthesis CYCLOHEXANE catalytic oxidation rare earths 

分 类 号：O643.36[理学—物理化学]