Atomic processes in the thermal destruction of zeolites as investigated by molecular dynamics and computer graphics
Atomic processes in the thermal destruction of zeolites as investigated by molecular dynamics and computer graphics
复制标题
通过分子动力学和计算机图形学研究沸石热破坏的原子过程
DOI：
10.1016/0920-5861(94)00158-x
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发表时间：
1995
期刊：
影响因子：
5.3
通讯作者：
A. Miyamoto
中科院分区：
文献类型：
--
作者：
Y. Oumi;Hideo Yamano;M. Kubo;R. Vetrivel;A. Miyamoto
用分子动力学和计算机图形学方法研究了ZSM-5型硅质岩（SiO2-MFI）、Cu-ZSM-5型硅质岩和八面沸石型硅质岩（SiO2-FAU）随温度升高的破坏过程。随着温度的升高，SiO2-MFI中原子的迁移率增加，骨架变得不稳定。最后，框架被破坏成无定形相。随着Al含量的增加，Cu-ZSM-5的耐热性降低。讨论了Si-O、Al-O和Cu-Al间距的变化以及Si-O键对的变化，以阐明Cu-ZSM-5的破坏机理。研究了SiO_2-FAU的破坏过程以了解骨架结构的影响，认为四元环的存在是SiO_2-FAU耐热性不如SiO_2-MFI的原因之一。
The destruction processes of various zeolites, such as a silicalite with the ZSM-5 structure (SiO2-MFI), Cu-ZSM-5, and a silicalite with the faujasite structure (SiO2-FAU), with increasing temperature were investigated by using molecular dynamics and computer graphics methods. The mobility of atoms in SiO2-MFI was increased and the framework became unstable, as the temperature was increased. Finally the framework was destroyed to an amorphous phase. Increasing the Al content led to a decrease in the heat-resistance in Cu-ZSM-5. The change in the Si-O, Al-O, and Cu-Al distances as well as the change in the pairs of Si-O bonds are discussed to clarify the mechanism of Cu-ZSM-5 destruction. The destruction process of SiO2-FAU was also investigated in order to understand the effect of framework structure, and it was suggested that the presence of the 4-membered ring provides one of the reasons for the inferior heat-resistance of SiO2-FAU to that of SiO2-MFI.