Datar Archit, Yoon Sunghyun, Lin Li-Chiang, Chung Yongchul G
William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States.
School of Chemical Engineering, Pusan National University, Busan 46241, South Korea.
Langmuir. 2022 Sep 27;38(38):11631-11640. doi: 10.1021/acs.langmuir.2c01390. Epub 2022 Sep 12.
Despite recommendations from the 2015 International Union of Pure and Applied Chemistry (IUPAC) technical report, surface areas of porous materials continue to be characterized by an N adsorption isotherm using the Brunauer-Emmett-Teller (BET) method. In this study, we provide the basis for such a practice by carrying out systematic large-scale molecular simulations on homogeneous and heterogeneous model surfaces. Specifically, we investigated the purported "orientational effect" of the N molecule on these surfaces. Grand canonical Monte Carlo (GCMC) simulation results from 257 diverse metal-organic frameworks show that the BET areas from Ar and N are similar in the range of 250-7500 m/g with a mean deviation of 4%. Detailed analyses based on the consistency criteria for BET equations reveal that the large deviation (>10%) between the BET areas from Ar and N are materials specific and more prone to materials that are not able to satisfy the 3 and 4 consistency criteria. For materials that satisfy all four consistency criteria, the BET areas predicted from Ar and N isotherms are comparable.
尽管2015年国际纯粹与应用化学联合会（IUPAC）技术报告给出了相关建议，但多孔材料的比表面积仍继续采用布鲁诺尔-埃米特-特勒（BET）法通过N吸附等温线来表征。在本研究中，我们通过对均匀和非均匀模型表面进行系统的大规模分子模拟，为这种做法提供了依据。具体而言，我们研究了N分子在这些表面上所谓的“取向效应”。来自257种不同金属有机框架的巨正则蒙特卡罗（GCMC）模拟结果表明，Ar和N的BET比表面积在250 - 7500 m²/g范围内相似，平均偏差为4%。基于BET方程一致性标准的详细分析表明，Ar和N的BET比表面积之间的大偏差（>10%）是材料特有的，并且更易出现在不满足3和4一致性标准的材料中。对于满足所有四个一致性标准的材料，由Ar和N等温线预测的BET比表面积具有可比性。
