Sequential Separation of Linear, Mono‐, and Di‐Branched Hexane Isomers on a Robust Coordination Polymer with Nonbonding Flexibility
Rundao Chen, Liangying Li, David H. Olson, Lidong Guo, Lihang Chen, Qiwei Yang, Qianqian Xu, Zhiguo Zhang, Qilong Ren, Jing Li, Zongbi Bao
Abstract
Abstract Efficient separation of hexane isomers is a crucial process for upgrading gasoline. Herein, the sequential separation of linear, mono‐, and di‐branched hexane isomers by a robust stacked 1D coordination polymer termed as Mn‐dhbq ([Mn(dhbq)(H 2 O) 2 ], H 2 dhbq = 2,5‐dihydroxy‐1,4‐benzoquinone) is reported. The interchain space of the activated polymer is of optimal aperture size (5.58 Å) that could exclude 2,3‐dimethylbutane, while the chain structure can discriminate n ‐hexane with high capacity (1.53 mmol g −1 at 393 K, 6.67 kPa) by high‐density open metal sites (5.18 mmol g −1 ). With the temperature‐ and adsorbate‐dependent swelling of interchain spaces, the affinity between 3‐methylpentane and Mn‐dhbq can be deliberately controlled from sorption to exclusion, and thus a complete separation of ternary mixture can be achieved. Column breakthrough experiments confirm the excellent separation performance of Mn‐dhbq. The ultrahigh stability and easy scalability further highlight the application prospect of Mn‐dhbq for separation of hexane isomers.