Understanding Adsorption and Separation behavior of shorter chain alkane mixtures in Zeolitic Imidazolate Frameworks by molecular simulations

AbstractNovel Zeolitic imidazolate frameworks (ZIFs) have attracted a lot of attentions in adsorption and catalysis owing to their superior properties to the traditional nanoporous materials. Grand canonical Monte Carlo combined with the configurational-bias Monte Carlo simulation was used to evaluate the adsorption isotherms of short linear alkane mixtures in ZIF-8 and-10.It is found that adsorbed amount of alkane molecules increases with the pressure increasing, the longer chain alkane molecules, the higher adsorption amount, and the adsorbed amounts of alkane molecules in ZIF-10 are larger than that in ZIF-8. The selectivities of the ZIFs for different components were further investigated and discussed, it is found that the selectivity of ZIF-10 is little higher than that of ZIF-8, but it is much lower than other zeolites. The adsorption sites of alkane mixtures were also obtained by mCT images, the adsorption mechanism of C1-C3 alkane mixtures in the ZIFs was analyzed, it may be helpful to design new ZIF materials with good adsorption and separation capability