Direct Synthesis of Well Ordered and Unusually Reactive FeSBA-15 Mesoporous Molecular Sieves
Direct Synthesis of Well Ordered and Unusually Reactive FeSBA-15 Mesoporous Molecular Sieves
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DOI：
10.1021/cm050883z
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发表时间：
2005-09
影响因子：
8.6
通讯作者：
A. Vinu;Dhanshri P. Sawant;K. Ariga;K. Z. Hossain;S. B. Halligudi;M. Hartmann;M. Nomura
中科院分区：
文献类型：
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作者：
A. Vinu;Dhanshri P. Sawant;K. Ariga;K. Z. Hossain;S. B. Halligudi;M. Hartmann;M. Nomura
首次在强酸性介质中合成了部分铁取代的大孔六方SBA-15分子筛。铁（III）结合到SBA-15中的程度可以通过简单地调节水和盐酸的摩尔比来容易地控制。所有材料均通过XRD、N2吸附、UV-维斯DRS、ESR和XANES光谱进行了表征。通过UV-维斯DRS、ESR和XANES光谱对FeSBA-15材料的表征表明，铁原子高度分散，并且大部分占据孤立的四面体位置。XANES研究表明，四面体配位的Fe原子的比例随着nSi/nFe比的降低而降低。研究了不同nSi/nFe比的FeSBA-15催化剂上苯（或取代苯）的苄基化反应。研究了反应温度、反应物投料比、催化剂存在等因素对反应的影响。
Large-pore hexagonal SBA-15 molecular sieves partially substituted with iron(III) have been synthesized for the first time in highly acidic media. The degree of iron(III) incorporation into SBA-15 can easily be controlled by a simple adjustment of the molar ratio of water and hydrochloric acid. All the materials have been characterized by XRD, N2 adsorption, UV−Vis DRS, ESR, and XANES spectroscopy. The characterization of the FeSBA-15 materials by UV−Vis DRS, ESR, and XANES spectroscopies suggests that the iron atoms are highly dispersed and mostly occupy isolated tetrahedral sites. XANES studies revealed that the proportion of tetrahedrally coordinated Fe atoms decreases with decreasing nSi/nFe ratios. Benzylation of benzene (or substituted benzenes) using benzyl chloride as the alkylating agent over FeSBA-15 with different nSi/nFe ratios was investigated as was the same reaction using AlSBA-15 as catalyst. The influence of parameters such as reaction temperature, reactant feed ratio, and the presence of...