当前位置：
X-MOL 学术
›
Angew. Chem. Int. Ed.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Kinetic Barriers and Microscopic Mechanisms of Noble Gas Adsorption by Nanoporous γ‐Mg(BH4)2 Obtained by Means of Sub‐Second X‐Ray Diffraction
Angewandte Chemie International Edition ( IF 16.1 ) Pub Date : 2020-11-16 , DOI: 10.1002/anie.202015019 Iurii Dovgaliuk 1, 2 , Irena Senkovska 3 , Xiao Li 4 , Vadim Dyadkin 1 , Yaroslav Filinchuk 4 , Dmitry Chernyshov 1
Angewandte Chemie International Edition ( IF 16.1 ) Pub Date : 2020-11-16 , DOI: 10.1002/anie.202015019 Iurii Dovgaliuk 1, 2 , Irena Senkovska 3 , Xiao Li 4 , Vadim Dyadkin 1 , Yaroslav Filinchuk 4 , Dmitry Chernyshov 1
Affiliation
|
Gas adsorption by porous frameworks sometimes results in structure “breathing”, “pores opening/closing”, “negative gas adsorption”, and other phenomena. Time‐dependent diffraction can address both kinetics of the guest uptake and structural response of the host framework. Using sub‐second in situ powder X‐ray diffraction, three intracrystalline diffusion scenarios have been evaluated from the isothermal kinetics of Ar, Kr, and Xe adsorption by nanoporous γ‐Mg(BH4)2. These scenarios are dictated by two possible simultaneous transport mechanisms: diffusion through the intra‐ (i) and interchannel apertures (ii) of γ‐Mg(BH4)2 crystal structure. The contribution of (i) and (ii) changes depending on the kinetic diameter of the noble gas molecule and temperature regime. The lowest single activation barrier for the smallest Ar suggests equal diffusion of the atoms trough both pathways. Contrary, for the medium sized Kr we resolve the contributions of two parallel transport mechanisms, which tentatively can be attributed to the smaller barrier of the migration paths via the channel like pores and the higher barrier for the diffusion via narrow aperture between these channels. The largest Xe atoms diffuse only along 1D channels and show the highest single activation barrier.
中文翻译：
亚秒级X射线衍射获得的纳米多孔γ-Mg（BH4）2吸附稀有气体的动力学壁垒和微观机理
多孔框架对气体的吸附有时会导致结构“呼吸”，“开/关孔”，“负气体吸附”和其他现象。随时间变化的衍射可以解决客体吸收动力学和宿主框架的结构响应。使用亚秒级原位粉末X射线衍射，通过纳米多孔γ-Mg（BH 4）2的Ar，Kr和Xe的等温动力学，评估了三种晶内扩散情形。这些场景由两种可能的同时传输机制决定：通过γ-Mg（BH 4）2的内部（i）和通道间孔（ii）扩散晶体结构。（i）和（ii）的贡献取决于稀有气体分子的动力学直径和温度范围而变化。最小Ar的最低单个激活势垒表明原子通过两个路径的扩散相同。相反，对于中等大小的K，我们解析了两种平行传输机制的贡献，这暂时可以归因于通过通道（如孔）的迁移路径的较小障碍，以及通过这些通道之间的窄孔进行扩散的较高的障碍。最大的Xe原子仅沿一维通道扩散，并显示出最高的单个激活势垒。
更新日期：2020-11-16
中文翻译：
亚秒级X射线衍射获得的纳米多孔γ-Mg（BH4）2吸附稀有气体的动力学壁垒和微观机理
多孔框架对气体的吸附有时会导致结构“呼吸”，“开/关孔”，“负气体吸附”和其他现象。随时间变化的衍射可以解决客体吸收动力学和宿主框架的结构响应。使用亚秒级原位粉末X射线衍射，通过纳米多孔γ-Mg（BH 4）2的Ar，Kr和Xe的等温动力学，评估了三种晶内扩散情形。这些场景由两种可能的同时传输机制决定：通过γ-Mg（BH 4）2的内部（i）和通道间孔（ii）扩散晶体结构。（i）和（ii）的贡献取决于稀有气体分子的动力学直径和温度范围而变化。最小Ar的最低单个激活势垒表明原子通过两个路径的扩散相同。相反，对于中等大小的K，我们解析了两种平行传输机制的贡献，这暂时可以归因于通过通道（如孔）的迁移路径的较小障碍，以及通过这些通道之间的窄孔进行扩散的较高的障碍。最大的Xe原子仅沿一维通道扩散，并显示出最高的单个激活势垒。
京公网安备 11010802027423号