Dual pore‐size sieving in a novel oxygenate‐pillared microporous adsorbent for <scp>C6</scp> alkane isomers separation
Yun Su, Rundao Chen, Peixin Zhang, Xiao He, Xing Liu, Yuan Liu, Hanting Xiong, Zhiwei Zhao, Junhui Luo, Jingwen Chen, Shixia Chen, Zeling Zeng, Zongbi Bao, Shuguang Deng, Jun Wang
Abstract
Abstract Adsorbents executing molecular sieving mechanisms for the efficient separation of n ‐hexane (C6) alkane isomers require delicate pore size control, but afford unsatisfactory single‐component separations according to their branch degrees. Herein, we report a novel oxygenate‐pillared microporous adsorbent, MoOFOUR‐Co‐tpb, ([Co(tpb) 2 MoO 4 ], tpb = 1,2,4,5‐tetra(pyridin‐4‐yl) benzene), with three gourd‐shaped channels for dual pore‐size sieving of C6 isomers. In particular, MoOFOUR‐Co‐tpb excludes 2,2‐dimethylbutane, while 3‐methylpentane (3MP) can enter one channel showing a high uptake of 82.6 mg g −1 , contrasting to the n ‐hexane ( n HEX) adsorption by two channels (136 mg g −1 ). This dual pore‐size control strategy renders a record high equilibrium–kinetic combined selectivity for n HEX/3MP (30.2). Moreover, three‐ and five‐component breakthrough experiments confirm the practical separation performances and cycling stability. Multiple theoretical simulations reveal the separation mechanism and adsorption sites.