Kaija Alec R, Wilmer Christopher E
Department of Chemical & Petroleum Engineering , University of Pittsburgh , 3700 O'Hara Street , Pittsburgh , Pennsylvania 15261 , United States.
J Phys Chem Lett. 2018 Aug 2;9(15):4275-4281. doi: 10.1021/acs.jpclett.8b01421. Epub 2018 Jul 17.
Decades of research have yet to yield porous adsorbents that meet the U.S. Department of Energy's methane storage targets. To better understand why, we calculated high-pressure methane adsorption in 600 000 randomly generated porous crystals, or "pseudomaterials," using atomistic grand canonical Monte Carlo (GCMC) simulations. These pseudomaterials were periodic configurations of Lennard-Jones spheres whose coordinates in space, along with corresponding well depths and radii, were all chosen at random. GCMC simulations were performed for pressures of 35 and 65 bar at a temperature of 298 K. Methane adsorption was compared for all materials against a range of other properties: average well depths and radii, number density, helium void fraction, and volumetric surface area. The results reveal structure-property relationships that resemble those previously observed for metal-organic frameworks and other porous materials. We contend that our computational methodology can be useful for discovering useful structure-property relationships related to gas adsorption without requiring experimentally accessible structural data.
数十年来的研究尚未产生能达到美国能源部甲烷储存目标的多孔吸附剂。为了更好地理解其中原因，我们使用原子级巨正则蒙特卡罗（GCMC）模拟，计算了60万个随机生成的多孔晶体（即“假材料”）中的高压甲烷吸附情况。这些假材料是 Lennard-Jones 球体的周期性构型，其空间坐标以及相应的阱深和半径均随机选取。在298 K的温度下，对35和65巴的压力进行了GCMC模拟。将所有材料的甲烷吸附情况与一系列其他性质进行了比较：平均阱深和半径、数密度、氦气孔隙率和体积表面积。结果揭示了与先前在金属有机框架和其他多孔材料中观察到的类似的结构-性质关系。我们认为，我们的计算方法可用于发现与气体吸附相关的有用结构-性质关系，而无需实验可获取的结构数据。
