Kinetic‐Sieving of Carbon Dioxide from Acetylene through a Novel Sulfonic Ultramicroporous Material

The engineering and tailoring of porous materials to realize the precise discrimination of CO2 and C2 H2 , with almost identical kinetic diameters, is a challenging task. We herein report the first example of the kinetic-sieving of relatively larger molecule of C2 H2 from CO2 by a novel sulfonic anion-pillared hybrid ultramicroporous materials of ZU-610a. Specifically, ZU-610 constructed from copper(II), isonicotinic acid and 1,2-ethanedisulfonic acid is synthesized and shows the preferential affinity for C2 H2 over CO2 . After the post-synthetic heat treatment of ZU-610, ZU-610a with a contracted aperture is obtained. Interestingly, the C2 H2 -selctive ZU-610 was reversed to the CO2 -selective ZU-610a. High purity C2 H2 (>99.5 %) could be directly obtained from the dynamic breakthrough experiments on an equimolar C2 H2 /CO2 mixture at 298 K. This study provides guidance for the design of adsorbents aimed at separation systems with similar kinetic diameter.