催化学报

催化学报 ›› 2011, Vol. 32 ›› Issue (4): 682-687.DOI: 10.3724/SP.J.1088.2011.01161

• 研究论文 • 上一篇    下一篇

MgO 催化剂上以 H2O2 为氧源的苯乙烯环氧化反应

边晓连, 谷庆明, 石雷, 孙琪*   

  1. 辽宁师范大学化学化工学院功能材料化学研究所 辽宁大连 116029
  • 收稿日期:2010-11-24 修回日期:2011-02-14 出版日期:2011-04-18 发布日期:2014-08-30

Epoxidation of Styrene with Hydrogen Peroxide over MgO Catalyst

BIAN Xiaolian, GU Qingming, SHI Lei, SUN Qi*   

  1. Institute of Chemistry for Functionalized Materials, Faculty of Chemistry and Chemical Enigineering, Liaoning Normal University, Dalian 116029, Liaoning, China
  • Received:2010-11-24 Revised:2011-02-14 Online:2011-04-18 Published:2014-08-30

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摘要： 采用直接焙烧 Mg(NO3)2•6H2O 制备了固体 MgO 催化剂, 并以 H2O2 为氧源, 乙腈为溶剂, 考察了其对苯乙烯环氧化反应的催化性能. 运用 X 射线衍射、N2 吸附-脱附、热重和 CO2 程序升温脱附对催化剂进行了表征. 结果表明, MgO 表面碱的强度在苯乙烯环氧化反应中起主导作用, 而其表面的碱量、比表面积及孔体积等的影响较小. 经 750 oC 焙烧制得 MgO-750 样品的碱性最强, 其催化性能最佳. 在 H2O2/苯乙烯摩尔比 = 6, 于 60 oC 反应 10 h 时, 苯乙烯转化率为 97.0%, 环氧苯乙烷选择性为 88.4%.

关键词: 氧化镁, 苯乙烯, 环氧化反应, 环氧苯乙烷, 乙腈, 过氧化氢

Abstract: A solid MgO catalyst was prepared by direct thermal decomposition of the Mg(NO3)2·6H2O precursor. The epoxidation of styrene was studied over the MgO using H2O2 as an oxidant in the presence of acetonitrile as solvent. The catalyst samples were characterized by X-ray diffraction, N2 adsorption-desorption, thermogravimetry, and CO2 temperature-programmed desorption. The results indicated that the strength of basic sites on the MgO catalyst is the key factor for the excellent performance of the catalyst. Enhancement of the strength of basic sites can increase the styrene conversion. In contrast, the number of basic sites, surface area, and pore volume of MgO have a relatively minor effect on catalytic activity. The MgO sample prepared by calcining Mg(NO3)2·6H2O at 750 oC showed the most strength of basic sites and the highest catalytic activity among the MgO samples calcined at 450–850 oC. Under the optimized reaction conditions, H2O2/styrene molar ratio = 6, acetonitrile as solvent, 60 oC, and 10 h, the conversion of styrene and the selectivity to epoxyethylbenzene were 97.0% and 88.4%, respectively.

Key words: magnesium oxide, styrene, epoxidation, epoxyethylbenzene, acetonitrile, hydrogen peroxide