Highly Enhanced Phenol Hydroxylation in [h0h]‐Oriented Fe–ZSM‐5 Membranes
Highly Enhanced Phenol Hydroxylation in [h0h]‐Oriented Fe–ZSM‐5 Membranes
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DOI：
10.1002/cctc.200900152
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发表时间：
2009-12
期刊：
影响因子：
4.5
通讯作者：
Lin Lang;X. Liu;Mingliang Hu;Baoquan Zhang
中科院分区：
文献类型：
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作者：
Lin Lang;X. Liu;Mingliang Hu;Baoquan Zhang
儿茶酚（CAT）和对苯二酚（HQ）是两种重要的二酚异构体，具有多种工业用途。过渡金属（TM）取代的ZSM - 5催化苯酚羟基化反应是一种环境友好的生产双酚的途径，该途径通常由晶内扩散控制。因此，高取向TM - ZSM - 5膜的可用性及其在间相膜反应器中的应用可以显著促进苯酚的羟基化反应。采用新的种子生长方法在多孔α - Al2O3表面制备了连续的[h0h]取向的Fe-ZSM - 5膜。利用SEM、XRD、UV/Vis和EPMA等技术对膜进行了表征，结果表明[h0h] -取向膜由Fe取代的ZSM - 5晶粒组成，Si/Fe比值约为75。与传统浆料反应器中装载不同粒径Fe-ZSM - 5颗粒的催化性能相比，间相膜反应器中[h0h]取向Fe-ZSM - 5膜由于分子筛膜中的分子路径控制，其苯酚转化率和对CAT和HQ的选择性显著提高。
Catechol (CAT) and hydroquinone (HQ) are two important diphenol isomers with a variety of industrial applications. The hydroxylation of phenol catalyzed by transition metal (TM) substituted ZSM‐5 is an environmentally benign route for diphenol production, which is usually governed by intracrystalline diffusion. Therefore, the availability of highly oriented TM‐ZSM‐5 membranes and their utilization in an interphase membrane reactor can significantly promote the hydroxylation of phenol. The continuous and [h0h]‐oriented Fe–ZSM‐5 membrane on the porous α‐Al2O3 was prepared using a new seeded growth method. Characterization was carried out by using SEM, XRD, UV/Vis, and EPMA techniques, which demonstrated that the [h0h]‐oriented membrane consists of Fe substituted ZSM‐5 crystal grains with an Si/Fe ratio of approximately 75. Compared with the catalytic performance of different sized Fe–ZSM‐5 grains loaded in the traditional slurry reactor, the [h0h]‐oriented Fe–ZSM‐5 membrane in the interphase membrane reactor showed significantly improved phenol conversion and selectivity for CAT and HQ due to the molecular path control in the zeolite membranes.