Liquid-phase epoxidation of cyclooctene with O2 over CoOx/SiO2 catalyst prepared by sol–gel method
Liquid-phase epoxidation of cyclooctene with O2 over CoOx/SiO2 catalyst prepared by sol–gel method
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DOI：
10.1007/s10971-011-2554-0
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发表时间：
2011-08
影响因子：
2.5
通讯作者：
B. Fan;Hang Qi;Xiufeng Shi;Ruifeng Li
中科院分区：
文献类型：
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作者：
B. Fan;Hang Qi;Xiufeng Shi;Ruifeng Li
采用溶胶-凝胶法制备了一系列CoOx/SiO2催化剂，并采用XRD、N2吸附/脱附、漫反射紫外-可见光谱、拉曼光谱和TPR技术进行了表征。这类材料对于环辛烯与大气分子氧的环氧化具有高活性和选择性。虽然在不同pH值下得到的催化剂均为非晶态，但由于pH值不仅影响Co物种的配位状态，还影响催化剂的织构结构，因此它们的催化活性存在显著差异，其中在pH值低于5时得到的CoOx/SiO2催化剂对环辛烯的环氧化反应具有高活性和选择性.所制备的CoOx/SiO2催化剂具有很高的稳定性，可重复使用至少4次而活性和选择性没有明显损失。
A series of CoOx/SiO2catalysts has been prepared by the sol–gel method and characterized with XRD, N2adsorption/desorption, diffuse reflectance UV–vis spectroscopy, Raman spectroscopy as well as TPR techniques. This type of material is highly active and selective for the epoxidation of cyclooctene with atmospheric molecular oxygen. Although all the catalysts attained at different pH values are amorphous, their catalytic activities are remarkably different because the pH values influence not only the coordination state of Co species but also the textural structures of the prepared catalysts, in which CoOx/SiO2obtained at pH below 5 is highly active and selective for the epoxidation of cyclooctene with atmospheric O2. The prepared CoOx/SiO2catalysts are highly stable and can be recycled at least four times without significant loss of activity and selectivity.