Nanostructured Maghemite-Supported Silver Catalysts for Styrene Epoxidation

The supported silver catalyst Ag/KOH-γ-Fe2O3 was prepared by simple impregnation and liquid reduction and then structurally characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The supported silver catalysts were highly efficient for the epoxidation of styrene using tert-butyl hydroperoxide as the oxidant and ethyl acetate as the reaction medium. The addition of KOH was found to increase the catalytic activity and selectivity significantly. Additionally, the magnetically recoverable γ-Fe2O3, as a support, allowed for an easy separation and recycling of the catalyst after the reaction.

摘要采用简单浸渍和液相还原法制备了 Ag/KOH-γ-Fe2O3 催化剂, 并采用 X 射线衍射、透射电镜和 X 射线光电子能谱等方法对催化剂进行了表征. 结果表明, 在乙酸乙酯介质中, 以叔丁基过氧化氢为氧化剂, 该催化剂具有较高的催化苯乙烯环氧化活性, KOH 的添加可大幅度提高环氧化反应活性和选择性. 表征结果显示, 反应前后催化剂性质没有发生明显的变化. 另外, 所使用的磁性载体有利于负载型银催化剂的分离和循环利用.

We prepared a Ag/KOH-γ-Fe2O3 catalyst and characterized it by various methods. We found that the magnetically separable catalyst was highly efficient for the epoxidation of styrene with tert-butyl hydroperoxide as an oxidant and ethyl acetate as the reaction medium.Figure optionsDownload as PowerPoint slide