Amino-functional CPL-1 with abundant CO2-philic groups to enhance MMM-based CO2 separation

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.