On the use of the IAST method for gas separation studies in porous materials with gate-opening behavior
On the use of the IAST method for gas separation studies in porous materials with gate-opening behavior
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DOI：
10.1007/s10450-018-9942-5
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发表时间：
2018-04-01
影响因子：
3.3
通讯作者：
Coudert, Francois-Xavier
中科院分区：
文献类型：
--
作者：
Fraux, Guillaume;Boutin, Anne;Coudert, Francois-Xavier
高度柔性的纳米多孔材料，表现出例如门打开或呼吸行为，由于其假定的高吸附选择性，通常被呈现为分离过程的候选者。但是，这种观点，基于刚性材料的“经典”考虑和理想吸附溶液理论（IAST）的使用，并不一定在框架变形的存在下成立。在这里，我们重新审视一些结果，从已发表的文献，并显示如何适当纳入框架的灵活性的渗透热力学合奏大大改变的结论，相反，什么直觉和标准的IAST会产生。在所有情况下，IAST方法不能再现混合物吸附中的开门行为，并且可能高估选择性高达两个数量级。[图形]
Highly flexible nanoporous materials, exhibiting for instance gate opening or breathing behavior, are often presented as candidates for separation processes due to their supposed high adsorption selectivity. But this view, based on " classical" considerations of rigid materials and the use of the Ideal Adsorbed Solution Theory (IAST), does not necessarily hold in the presence of framework deformations. Here, we revisit some results from the published literature and show how proper inclusion of framework flexibility in the osmotic thermodynamic ensemble drastically changes the conclusions, in contrast to what intuition and standard IAST would yield. In all cases, the IAST method does not reproduce the gate- opening behavior in the adsorption of mixtures, and may overestimates the selectivity by up to two orders of magnitude.[GRAPHICS]