A molecular sieve with ultrafast adsorption kinetics for propylene separation
Jiyu Cui, Zhaoqiang Zhang, Lifeng Yang, Jianbo Hu, Anye Jin, Zhenglu Yang, Yue Zhao, Biao Meng, Yu Zhou, Jun Wang, Yun Su, Jun Wang, Xili Cui, Huabin Xing
Abstract
The design of molecular sieves is vital for gas separation, but it suffers from a long-standing issue of slow adsorption kinetics due to the intrinsic contradiction between molecular sieving and diffusion within restricted nanopores. We report a molecular sieve ZU-609 with local sieving channels that feature molecular sieving gates and rapid diffusion channels. The precise cross-sectional cutoff of molecular sieving gates enables the exclusion of propane from propylene. The coexisting large channels constituted by sulfonic anions and helically arranged metal-organic architectures allow the fast adsorption kinetics of propylene, and the measured propylene diffusion coefficient in ZU-609 is one to two orders of magnitude higher than previous molecular sieves. Propylene with 99.9% purity is obtained through breakthrough experiments with a productivity of 32.2 L kg −1 .