Internal versus external surface active sites in ZSM-5 zeolite -: Part 1.: Fries rearrangement catalyzed by modified and unmodified H3PO4/ZSM-5
Internal versus external surface active sites in ZSM-5 zeolite -: Part 1.: Fries rearrangement catalyzed by modified and unmodified H3PO4/ZSM-5
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DOI：
10.1016/j.apcata.2005.09.015
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发表时间：
2006-01-10
影响因子：
5.5
通讯作者：
Kalbasi, RJ
中科院分区：
文献类型：
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作者：
Ghiaci, M;Abbaspur, A;Kalbasi, RJ
在一系列负载 H(3)PO(4) 的表面改性和未改性 ZSM-5 (Si/Al = 60-170) 上，研究了 623 K 气相中乙酸苯酯的弗里斯重排，沸石的外表面处理不同。当沸石的外表面在负载H(3)PO(4)之前用表面活性剂封闭时，形成4-羟基苯乙酮的选择性更高。相对于未改性的H(3)PO(4)/ZSM-5催化剂，外部封闭催化剂的这种优越性能表明，通过封闭ZSM-5载体的外表面积，其表现出比未改性催化剂更优异的催化选择性。使用改性和未改性的ZSM-5沸石制备了含0-4.9wt.%P的催化剂，及其对乙酸苯酯气相弗赖斯重排的催化性能测定了2-羟基苯乙酮(2-HAP)、4-羟基苯乙酮(4-HAP)和4-乙酰氧基苯乙酮(4-AAP)。还研究了操作参数对H(3)PO(4)/ZSM-5-surf催化剂性能的影响。 (c) 2005 Elsevier B.V. 保留所有权利。
The Fries rearrangement of phenylacetate has been studied in the vapor-phase at 623 K over a series of surface modified and unmodified ZSM-5 (Si/Al = 60-170) loaded with H(3)PO(4), differing in the external surface treatment of the zeolites. When the external surface of the zeolite is blocked with a surfactant before loading it with H(3)PO(4), the selectivity to form the 4-hydroxyacetophenone was higher. This superior performance of the externally blocked catalysts, relative to the unmodified H(3)PO(4)/ZSM-5 catalyst, shows that by blocking the external surface area of the ZSM-5 support, it exhibits a superior catalytic selectivity than the unmodified catalyst.Catalysts containing 0-4.9 wt.% P were prepared using modified and unmodified ZSM-5 zeolites, and their catalytic performance for vapor-phase Fries rearrangement of phenylacetate to 2-hydroxyacetophenone (2-HAP), 4-hydroxyacetophenone (4-HAP) and 4-acetoxyacetophenone (4-AAP) was determined. The influence of the operating parameters on the performance of H(3)PO(4)/ZSM-5-surf catalysts was also investigated. (c) 2005 Elsevier B.V. All rights reserved.