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 C2H2, with almost identical kinetic diameters, is a challenging task. We herein report the first example of the kinetic-sieving of relatively larger molecule of C2H2 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 C2H2 over CO2. After the post-synthetic heat treatment of ZU-610, ZU-610a with a contracted aperture is obtained. Interestingly, the C2H2-selctive ZU-610 was reversed to the CO2-selective ZU-610a. High purity C2H2 (>99.5 %) could be directly obtained from the dynamic breakthrough experiments on an equimolar C2H2/CO2 mixture at 298 K. This study provides guidance for the design of adsorbents aimed at separation systems with similar kinetic diameter.

Automated summary

In this study, we report a porous material, ZU-610a, which can precisely discriminate between CO2 and C2H2 through kinetic sieving. This material is able to selectively separate larger molecules of C2H2 from CO2, providing guidance for the design of adsorbents with similar kinetic diameters.