A Microporous Metal‐Organic Framework with Unique Aromatic Pore Surfaces for High Performance C<sub>2</sub>H<sub>6</sub>/C<sub>2</sub>H<sub>4</sub> Separation
Yingxiang Ye, Yi Xie, Yanshu Shi, Lingshan Gong, Joshua Phipps, Abdullah M. Al‐Enizi, Ayman Nafady, Banglin Chen, Shengqian Ma
Abstract
Abstract Developing adsorptive separation processes based on C 2 H 6 ‐selective sorbents to replace energy‐intensive cryogenic distillation is a promising alternative for C 2 H 4 purification from C 2 H 4 /C 2 H 6 mixtures, which however remains challenging. During our studies on two isostructural metal–organic frameworks ( Ni‐MOF 1 and Ni‐MOF 2 ), we found that Ni‐MOF 2 exhibited significantly higher performance for C 2 H 6 /C 2 H 4 separation than Ni‐MOF‐1 , as clearly established by gas sorption isotherms and breakthrough experiments. Density‐Functional Theory (DFT) studies showed that the unblocked unique aromatic pore surfaces within Ni‐MOF 2 induce more and stronger C−H⋅⋅⋅π with C 2 H 6 over C 2 H 4 while the suitable pore spaces enforce its high C 2 H 6 uptake capacity, featuring Ni‐MOF 2 as one of the best porous materials for this very important gas separation. It generates 12 L kg −1 of polymer‐grade C 2 H 4 product from equimolar C 2 H 6 /C 2 H 4 mixtures at ambient conditions.