Enhanced Methane Adsorption in Catenated Metal-organic Frameworks： A Molecular Simulation Study

A systematic molecular simulation study was performed to investigate the effect of catenation on methane adsorption in metal-organic frameworks(MOFs).Four pairs of isoreticular MOFs(IRMOFs)with and without catenation were adopted and their capacities for methane adsorption were compared at room temperature.The present work showed that catenation could greatly enhance the storage capacity of methane in MOFs,due to the formation of additional small pores and adsorption sites formed by the catenation of frameworks.In addition,the simulation results obtained at 298K and 3.5MPa showed that catenated MOFs could easily meet the requirement for methane storage in porous materials.

新型储甲烷金属-有机骨架材料的设计

针对迄今具有最大甲烷存储量的金属-有机骨架(MOF)材料PCN-14,采用质心分布图研究了甲烷在其中的吸附机理.结果表明,PCN-14中主要存在两个吸附位,并且有机配体对材料吸附甲烷有着重要影响.因此,通过改变有机配体的类型,设计了对甲烷具有更高吸附性能的新型MOF材料PCN-M.PCN-M在3.5 MPa下、290 K时对甲烷的吸附量达到了257 V/V,比PCN-14增加了12%;298 K时对甲烷的吸附量达到了241 V/V,超过了DOE标准180 V/V的34%.此外,本工作表明了改变有机配体是改善材料存储甲烷能力的一种可行方法,为合成高甲烷储存量的新MOF材料提供了理论依据.