Materials and Process Simulation Center (MC 139-74), California Institute of Technology, Pasadena, California 91125, USA.
J Phys Chem A. 2011 Dec 1;115(47):13852-7. doi: 10.1021/jp209541e. Epub 2011 Nov 7.
We designed 14 new covalent organic frameworks (COFs), which are expected to adsorb large amounts of methane (CH(4)) at 298 K and up to 300 bar. We have calculated their delivery uptake using grand canonical Monte Carlo (GCMC) simulations. We also report their thermodynamic stability based on 7.5 ns molecular dynamics simulations. Two new frameworks, COF-103-Eth-trans and COF-102-Ant, are found to exceed the DOE target of 180 v(STP)/v at 35 bar for methane storage. Their performance is comparable to the best previously reported materials: PCN-14 and Ni-MOF-74. Our results indicate that using thin vinyl bridging groups aid performance by minimizing the interaction methane-COF at low pressure. This is a new feature that can be used to enhance loading in addition to the common practice of adding extra fused benzene rings. Most importantly, this report shows that pure nonbonding interactions, van der Waals (vdW) and electrostatic forces in light elements (C, O, B, H, and Si), can rival the enhancement in uptake obtained for microporous materials derived from early transition metals.
我们设计了 14 种新型共价有机骨架（COFs），预计它们可以在 298 K 和高达 300 巴的条件下吸附大量甲烷（CH(4)）。我们已经使用巨正则蒙特卡罗（GCMC）模拟计算了它们的输送吸收量。我们还根据 7.5 ns 分子动力学模拟报告了它们的热力学稳定性。发现两个新的框架，COF-103-Eth-trans 和 COF-102-Ant，在 35 巴下的甲烷存储量超过了 DOE 的 180 v(STP)/v 的目标。它们的性能与之前报道的最好的材料相当：PCN-14 和 Ni-MOF-74。我们的结果表明，使用薄的乙烯基桥连基团可以通过最小化甲烷-COF 在低压下的相互作用来提高性能。这是一个新的特点，可以用于除了增加额外的稠合苯环之外，还可以增强负载。最重要的是，本报告表明，纯非键相互作用、范德华（vdW）和轻元素（C、O、B、H 和 Si）的静电相互作用，可以与从早期过渡金属衍生的微孔材料获得的吸收增强相媲美。
