Frost Houston, Düren Tina, Snurr Randall Q
Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
J Phys Chem B. 2006 May 18;110(19):9565-70. doi: 10.1021/jp060433+.
Grand canonical Monte Carlo simulations were performed to predict adsorption isotherms for hydrogen in a series of 10 isoreticular metal-organic frameworks (IRMOFs). The results show acceptable agreement with the limited experimental results from the literature. The effects of surface area, free volume, and heat of adsorption on hydrogen uptake were investigated by performing simulations over a wide range of pressures on this set of materials, which all have the same framework topology and surface chemistry but varying pore sizes. The results reveal the existence of three adsorption regimes: at low pressure (loading), hydrogen uptake correlates with the heat of adsorption; at intermediate pressure, uptake correlates with the surface area; and at the highest pressures, uptake correlates with the free volume. The accessible surface area and free volume, calculated from the crystal structures, were also used to estimate the potential of these materials to meet gravimetric and volumetric targets for hydrogen storage in IRMOFs.
进行了巨正则蒙特卡罗模拟，以预测一系列10种同网状金属有机骨架（IRMOF）中氢气的吸附等温线。结果与文献中有限的实验结果显示出可接受的一致性。通过在广泛的压力范围内对这组材料进行模拟，研究了表面积、自由体积和吸附热对氢气吸收的影响，这些材料都具有相同的骨架拓扑结构和表面化学性质，但孔径不同。结果揭示了三种吸附状态的存在：在低压（负载）下，氢气吸收与吸附热相关；在中压下，吸收与表面积相关；在最高压力下，吸收与自由体积相关。从晶体结构计算得到的可及表面积和自由体积，也被用于估计这些材料实现IRMOF中氢气存储重量和体积目标的潜力。
