Polarizable Force Field for CO2 in M-MOF-74 Derived from Quantum Mechanics
Polarizable Force Field for CO2 in M-MOF-74 Derived from Quantum Mechanics
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DOI：
10.1021/acs.jpcc.8b08639
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发表时间：
2018-10-25
影响因子：
3.7
通讯作者：
Vlugt, Thijs J. H.
中科院分区：
文献类型：
--
作者：
Becker, Tim M.;Lin, Li-Chiang;Vlugt, Thijs J. H.
从短期来看，碳捕获是减少人类导致的二氧化碳排放的可行解决方案，这需要高效地分离二氧化碳。金属有机框架(MOF)可以提供碳捕获和其他工业相关分离的机会。特别是，具有嵌入的开放金属中心的MOF已被证明是有前景的。甚至在材料合成之前，分子模拟就是预测MOF性能的有用工具。这减少了实验工作量，并且可以加快选择最适合特定应用的MOF的过程。在分子模拟中描述开放金属中心与客体分子之间的相互作用是具有挑战性的。可极化力场有可能改善对这种特定相互作用的描述。此前，我们通过验证重现实验测量的能力，测试了可极化力场在M-MOF-74中对二氧化碳的适用性。在这里，我们建立了一个预测CO_2在M-MOF-74(M=Co，Fe，Mg，Mn，Ni，Zn)中的极化力场，而不需要实验数据。力场是从量子力学预测的能量中得出的。该程序可以很容易地转移到其他MOF。为了引入显式极化，在骨架和客体分子之间采用了诱导偶极子方法。原子的极化率是根据文献进行分配的。只有开放金属位置的Leonard-Jones参数被参数化，以复制来自量子力学的能量。在M-MOF-74中建立的CO2极化力场能够很好地描述吸附，甚至比我们以前的工作更好地描述了吸附。
On the short term, carbon capture is a viable solution to reduce human-induced CO2 emissions, which requires an energy efficient separation of CO2. Metal-organic frameworks (MOFs) may offer opportunities for carbon capture and other industrially relevant separations. Especially, MOFs with embedded open metal sites have been shown to be promising. Molecular simulation is a useful tool to predict the performance of MOFs even before the synthesis of the material. This reduces the experimental effort, and the selection process of the most suitable MOF for a particular application can be accelerated. To describe the interactions between open metal sites and guest molecules in molecular simulation is challenging. Polarizable force fields have potential to improve the description of such specific interactions. Previously, we tested the applicability of polarizable force fields for CO2 in M-MOF-74 by verifying the ability to reproduce experimental measurements. Here, we develop a predictive polarizable force field for CO2 in M-MOF-74 (M = Co, Fe, Mg, Mn, Ni, Zn) without the requirement of experimental data. The force field is derived from energies predicted from quantum mechanics. The procedure is easily transferable to other MOFs. To incorporate explicit polarization, the induced dipole method is applied between the framework and the guest molecule. Atomic polarizabilities are assigned according to the literature. Only the Leonard-Jones parameters of the open metal sites are parameterized to reproduce energies from quantum mechanics. The created polarizable force field for CO2 in M-MOF-74 can describe the adsorption well and even better than that in our previous work.