Commensurate stacking within confined ultramicropores boosting acetylene storage capacity and separation efficiency
Zhenghui Huang, Kungang Chai, Chengjun Kang, Rajamani Krishna, Zhaoqiang Zhang
Abstract
Abstract Developing advanced porous materials possessing both a high storage capacity and selectivity for acetylene (C 2 H 2 ) remains challenging but a sought-after endeavor. Herein we show a strategy involving synergic combination of spatial confinement and commensurate stacking for enhanced C 2 H 2 storage and capture via maximizing the host—guest and guest—guest interactions. Two ultramicroporous metal-organic frameworks (MOFs), MIL-160 and MOF-303 are elaborately constructed to exhibit ultrahigh C 2 H 2 uptakes of 235 and 195 cm 3 ·g −1 , respectively, due to the confinement effect of the suitable pore sizes and periodically dispersed molecular recognition sites. Specially, C 2 H 2 capacity of MIL-160 sets a new benchmark for C 2 H 2 storage. The exceptional separation performances of two materials for C 2 H 2 over both CO 2 and ethylene (C 2 H 4 ), which is rarely observed, outperform most of the benchmark materials for C 2 H 2 capture. We scrutinized the origins of ultrahigh C 2 H 2 loading in the confined channels via theoretical investigations. The superior separation efficiency for C 2 H 2 /CO 2 and C 2 H 2 /C 2 H 4 mixtures with unprecedented C 2 H 2 trapping capacity (> 200 L·kg −1 ) was further demonstrated by dynamic breakthrough experiments.