Amino-functional CPL-1 with abundant CO2-philic groups to enhance MMM-based CO2 separation
Huahao Wang, Ding Yaping, Mengjia Ning, Miao Yu, Wenji Zheng, Xuehua Ruan, Yuan Xi, Yan Dai, Hongjing Liu, Gaohong He
Abstract
Metal organic frameworks (MOFs) with appropriate pore size and sufficient CO 2 -philic groups are required to improve the mixed matrix membranes (MMMs)-based CO 2 capture. Herein, NH 2 -CPL-1 is designed for capture by utilizing amino pyrazine instead of pyrazine in CPL-1. The introduced CO 2 -philic amino groups together with rich hydroxyl and carboxyl groups in CPL-1 could improve the selective adsorption of CO 2 , enhancing the solubility selectivity. At the meantime, after the introduction of amino-functional, the pore size of NH 2 -CPL-1 is decreased from 0.93 nm of CPL-1 to 0.85 nm, which is beneficial for the screening of CO 2 over N 2 . As a result, the CO 2 separation performances of MMMs could be promoted greatly under the action of NH 2 -CPL-1. MMM with NH 2 -CPL-1 of 10 wt.% exhibited the best CO 2 separation performance, with CO 2 /N 2 selectivity of 85 and CO 2 permeability of 104 Barrer at 25 °C and 0.4 MPa. Compared with the CPL-1/Pebax-10 wt.% MMM, it was increased by 9.5 % and 13.3 %, respectively. This satisfactory CO 2 separation performance surpasses those of most reported other MOFs based MMMs, which is attributed to the facilitated CO 2 transport and pore size screening from the introduced amino groups. This is also confirmed by the improvement of diffusion selectivity and solution selectivity. The proposed NH 2 -CPL-1 shows great prospect as filler for enhanced MMMs-based CO 2 capture.