A Transferable Model for Adsorption in MOFs with Unsaturated Metal Sites
A Transferable Model for Adsorption in MOFs with Unsaturated Metal Sites
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DOI：
10.1021/acs.jpcc.6b10751
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发表时间：
2017-01-12
影响因子：
3.7
通讯作者：
Jorge, Miguel
中科院分区：
文献类型：
--
作者：
Campbell, Christopher;Ferreiro-Rangel, Carlos A.;Jorge, Miguel
新发现的金属-有机框架的数量呈指数级增长。分子模拟对于筛选大型结构数据库和识别具有挑战性的气体分离的潜在候选者变得越来越重要，但这些努力依赖于准确分子模型的可用性，这些模型可以预测各种不同MOF中的吸附。具有配位不饱和位点（CUS）的MOFs提出了特殊的问题，因为标准力场无法描述它们与某些吸附物的特定相互作用。在这篇文章中，我们证明了我们以前的方法来描述吸附在开放的金属网站，基于经典的Monte Carlo模拟和量子力学密度泛函理论计算的组合，是可转移到几个含铜的MOFs。通过拟合我们的模型的参数，以匹配HKUST-1上的乙烯吸附能，并将它们转移到其他MOFs的铜桨轮单元，我们得到的预测与实验吸附，测量吻合得很好。在协议是不令人满意的），我们表明，这可以解释为有限的可访问性或通过孔隙网络的扩散。对于一个特定的MOF，UMCM-150，我们表明，单独的参数需要用于铜三聚体单元，与乙烯的相互作用能要低得多，比那些在铜桨轮。总的来说，我们的方法表明，特定的CUS相互作用的MOFs可以单独参数化从其他相互作用类型，如货车德瓦尔斯，从而开辟了道路的发展。精确和完全可转移的力场。
The number of newly discovered metal- organic frameworks is growing exponentially. Molecular simulation is becoming increasingly important to screen large databases of structures and identify potential candidates for challenging gas separations, but such efforts rely on the availability of accurate molecular models that can,predict adsorption in a Wide range of :different MOFs. MOFs with coordinatively unsaturated sites (CUS) pose particular problems because standard force fields are unable to, describe their specific interactions with certain adsorbates. In this Article, we demonstrate that our previous approach to describe adsorption in open metal sites, based on a combination, of classical Monte Carlo simulations and quantum-mechanical Density Functional Theory calculations, is transferable to several Cu-containing MOFs. By fitting the parameters of our model to match adsorption energies of ethylene on HKUST-1 and transferring them to the Cu-paddlewheel units of other MOFs, we obtain predictions in good agreement with experimental adsorption,measurements. Where agreement is not as satisfactory) we show that this can be explained by limited accessibility or diffusion through the pore network. For one particular MOF, UMCM-150, we show that separate parameters need to be used for the Cu-trimer unit, for which the interaction energies with ethylene are much lower, than those in the Cu-paddlewheel. Overall, our approach demonstrates that the specific CUS interactions in MOFs can be parametrized separately from other interaction types, such as van der Waals, thus opening the way for the development of an. accurate and fully transferable force field for this class of materials.