Surface functionalization of SBA-15-ordered mesoporous silicas: Oxidation of benzene to phenol by nitrous oxide
Surface functionalization of SBA-15-ordered mesoporous silicas: Oxidation of benzene to phenol by nitrous oxide
复制标题
SBA-15有序介孔二氧化硅的表面功能化：一氧化二氮将苯氧化为苯酚
DOI：
10.1016/j.jcat.2008.02.001
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发表时间：
2008-04-25
影响因子：
7.3
通讯作者：
Li, Can
中科院分区：
文献类型：
--
作者：
Li, Ying;Feng, Zhaochi;Li, Can
报道了直接水热合成法制备高有序介孔Fe-Ga-SBA-15材料及其催化性能。将镓和铁离子直接引入合成凝胶中，这是制备SBA-15的典型步骤。得到的材料具有约6 nm的六方有序介孔，比表面积约为1000m(2)/g。在Fe-SBA-15中，铁物种主要以四面体配位的方式存在于无定形二氧化硅中。在Ga(Fe-Ga-SBA-15)存在下，拉曼光谱和漫反射UV-Vis光谱表明，Fe以孤立物种的形式存在于二氧化硅表面。Fe-Ga-SBA-15分子筛中的Fe物种表现出与FeZSM-5分子筛相似的氧化亚氮分解性能，并对氧化亚氮氧化苯制苯酚具有催化活性。而Ga-SBA-15和Fe-SBA-15则无催化活性。与Fe-Al-SBA-15相比，Fe-Ga-SBA-15对苯酚产物具有更高的选择性。(C)2008 Elsevier Inc.保留所有权利。
We report the preparation and catalytic properties of highly ordered mesoporous Fe-Ga-SBA-15 materials via direct hydrothermal synthesis. Gallium and iron ions were introduced directly into the synthesis gel typical for the preparation of SBA-15. The resulting materials had hexagonally ordered mesopores of about 6 nm and surface areas >1000 m(2)/g. In Fe-SBA-15, the iron species were mainly tetrahedrally coordinated in the amorphous silica walls. In the presence of Ga (Fe-Ga-SBA-15), Fe species were located at the silica surface as isolated species, as determined by Raman and diffuse-reflectance UV-Vis spectroscopy measurements. The Fe species in Fe-Ga-SBA-15 displayed similar properties as the FeZSM-5 zeolites toward nitrous oxide decomposition and were active in the oxidation of benzene to phenol by nitrous oxide. Ga-SBA-15 and Fe-SBA-15, on the other hand, showed no catalytic activity. Compared with Fe-Al-SBA-15, Fe-Ga-SBA-15 displayed greater selectivity to the desired phenol product. (C) 2008 Elsevier Inc. All rights reserved.