ABSTRACT

Over the past decades, the associated research on metal-organic

frameworks (MOFs) has been rapidly developed into one of the

most prolific areas in chemistry, chemical engineering, and material

science [1-5]. The intrinsic nature of MOFs allows the ability

of systematically modulating the pore dimensions, surface areas,

topologies and surface chemistry within them in an extremely

broad range. This remarkable feature of MOFs is largely absent in

conventional porous materials such as zeolites [6], which permits

MOFs to serve as an ideal platform for various specific targets

and thus puts them in a unique position. For this reason, one of

significant efforts has been devoted in recent years to explore and

improve the performance of MOFs for gas separation [5]. From

an experimental point of view, it is not only very time consuming

to explore the thousands of MOFs reported in the literature, but

also the direct measurements on the related behaviors of mixtures

confined in MOFs remain challenging. In addition, highly detailed

information that leads to the macroscopic properties observed

in MOFs is as well not easy to be addressed using experimental

methods. In contrast, molecular modeling provides a very valuable

complement to experimental studies of MOFs, which can give

deep insights into the mechanisms that control the gas separation

capability of MOFs at amolecular level. Comparedwith experiments,

this method can be utilized to isolate the key influencing factors and

quantify their separate contributions to the separation behaviors of

a large population of MOFs [7], as well as the cooperative effects

among a set of selected factors [8]. Furthermore, due to a variety

of inorganic and organic moieties, it offers a theoretically unlimited

number of possible structures of MOFs. Molecular modeling is then

a particularly attractive tool for large-scale virtual screening of the

existing MOFs and new hypothetical MOFs designed by computer [7,

9-11], allowing experimental endeavors to only concentrate on the

candidates with the most promising separation performance.