External or internal surface of H-ZSM-5 zeolite, which is more effective for the Beckmann rearrangement reaction?
External or internal surface of H-ZSM-5 zeolite, which is more effective for the Beckmann rearrangement reaction?
复制标题
H-ZSM-5沸石的外表面和内表面，哪个对贝克曼重排反应更有效？
DOI：
10.1039/c7cy00377c
复制
发表时间：
2017-06-21
影响因子：
5
通讯作者：
Deng, Feng
中科院分区：
文献类型：
--
作者：
Chu, Yueying;Li, Guangchao;Deng, Feng
Zeolites are effective catalysts for amide formation from oxime through the Beckmann rearrangement (BR) reaction; however, debates about which surface (i.e. external or internal) is more effective for the BR reaction over zeolites still remain. In this contribution, the effective rate constants (keff) are used to quantitatively evaluate the dependence of BR reactivity on the Bronsted acid location in H-ZSM-5 zeolite. Based on our theoretical calculations, it was found that in addition to the dimension size of oxime reactants and reaction temperature, the BR reaction is strongly dependent on the location of Bronsted acid sites. For the cyclohexanone oxime rearrangement, the reaction exclusively occurs on the internal surface of ZSM-5 zeolite at room temperature, while the active sites are those located at the pore mouth or on the external surface when the reaction temperature increases to 598 K. In contrast to cyclohexanone oxime, the Bronsted acid sites on the internal surface are kinetically more effective at room temperature or 598 K for the smaller acetoxime BR reaction.
