Accurate Characterization of the Pore Volume in Microporous Crystalline Materials (Data Download)

Project Abstract: Pore volume is one of the main properties for the characterization of microporous crystals. It is experimentally measurable and it can also be obtained from the refined unit cell by a number of computational techniques. In this work we assess the accuracy and the discrepancies between the different computational methods which are commonly used for this purpose, i.e, geometric, helium and probe center pore volume, by studying a database of more than 5000 frameworks. We developed a new technique to fully characterize the internal void of a microporous material and to compute the probe accessible and occupiable pore volume. We show that unlike the other definitions of pore volume, the occupiable pore volume can be directly related to the experimentally measured pore volumes from nitrogen isotherms.

项目摘要：孔体积是表征微孔晶体的核心物性之一。该参数既可通过实验手段直接测得，也可依托多种计算技术从精修后的晶胞中推导得到。本研究基于包含5000余个骨架结构的数据库，对该类计算常用的三类方法——几何法孔体积、氦气法孔体积与探针中心法孔体积的精度及结果间的差异进行了评估。此外，本研究开发了一种全新的表征方法，可完整刻画微孔材料的内部孔道空间，并计算得到探针可及与可占据孔体积。研究表明，与其他孔体积定义不同，可占据孔体积可直接与通过氮气吸附等温线实验测得的孔体积建立关联。