Becker Tim M, Heinen Jurn, Dubbeldam David, Lin Li-Chiang, Vlugt Thijs J H
Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology , Leeghwaterstraat 39, 2628CB Delft, The Netherlands.
Van't Hoff Institute for Molecular Sciences, University of Amsterdam , Science Park 904, 1098XH Amsterdam, The Netherlands.
J Phys Chem C Nanomater Interfaces. 2017 Mar 2;121(8):4659-4673. doi: 10.1021/acs.jpcc.6b12052. Epub 2017 Jan 31.
The family of M-MOF-74, with M = Co, Cr, Cu, Fe, Mg, Mn, Ni, Ti, V, and Zn, provides opportunities for numerous energy related gas separation applications. The pore structure of M-MOF-74 exhibits a high internal surface area and an exceptionally large adsorption capacity. The chemical environment of the adsorbate molecule in M-MOF-74 can be tuned by exchanging the metal ion incorporated in the structure. To optimize materials for a given separation process, insights into how the choice of the metal ion affects the interaction strength with adsorbate molecules and how to model these interactions are essential. Here, we quantitatively highlight the importance of polarization by comparing the proposed polarizable force field to orbital interaction energies from DFT calculations. Adsorption isotherms and heats of adsorption are computed for CO, CH, and their mixtures in M-MOF-74 with all 10 metal ions. The results are compared to experimental data, and to previous simulation results using nonpolarizable force fields derived from quantum mechanics. To the best of our knowledge, the developed polarizable force field is the only one so far trying to cover such a large set of possible metal ions. For the majority of metal ions, our simulations are in good agreement with experiments, demonstrating the effectiveness of our polarizable potential and the transferability of the adopted approach.
M = Co、Cr、Cu、Fe、Mg、Mn、Ni、Ti、V和Zn的M-MOF-74家族为众多与能源相关的气体分离应用提供了机会。M-MOF-74的孔结构具有高内表面积和超大吸附容量。通过交换结构中所含的金属离子，可以调节M-MOF-74中吸附质分子的化学环境。为了优化给定分离过程的材料，深入了解金属离子的选择如何影响与吸附质分子的相互作用强度以及如何对这些相互作用进行建模至关重要。在这里，我们通过将所提出的可极化力场与密度泛函理论（DFT）计算得到的轨道相互作用能进行比较，定量地突出了极化的重要性。计算了CO、CH及其混合物在含有所有10种金属离子的M-MOF-74中的吸附等温线和吸附热。将结果与实验数据以及使用从量子力学导出的非可极化力场的先前模拟结果进行比较。据我们所知，所开发的可极化力场是迄今为止唯一试图涵盖如此大量可能金属离子的力场。对于大多数金属离子，我们的模拟与实验结果吻合良好，证明了我们可极化势的有效性以及所采用方法的可转移性。
