High-Capacity Splitting of Mono- and Dibranched Hexane Isomers by a Robust Zinc-Based Metal-Organic Framework.

Abstract

High-efficiency separation of C6 alkanes, particularly the mono- and dibranched isomers by using porous solids, is of paramount significance in the petrochemical industry and, remains a daunting challenge. In this work, we report the complete separation of linear/monobranched hexanes from their dibranched isomers through selective size-exclusion by a microporous MOF, Zn-tcpt (H3 tcpt=2,4,6-tris(4-carboxyphenoxy)-1,3,5-triazine), with a two-fold interpenetrated structure of hms nets. Importantly, its adsorption capacity and selectivity are notably higher than those of the previously reported adsorbents that can split mono- and dibranched alkane isomers. Dynamic breakthrough measurements verify the excellent separation of C6 alkane isomers by Zn-tcpt, and the size-exclusion based separation mechanism has been confirmed by ab initio materials modeling. The high-efficiency separation of alkane isomers by Zn-tcpt can be attributed to its optimal pore dimensions as well as high porosity.