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

• Published in: Journal of rare earths Vol. 26; no. 4; pp. 515 - 522
• Main Author: 詹望成 卢冠忠 郭杨龙 郭耘 王艳芹 王筠松 张志刚 刘晓晖
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2008; Lab for Advanced Materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai 200237, China
• Subjects: catalytic oxidation; Ce-doped MCM-48; cyclohexane; rare earths; synthesis; 催化氧化; 化学分析; 环己烷; synthesis; Ce-doped MCM-48; cyclohexane; catalytic oxidation; rare earths
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(08)60129-5

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.