Fabrication of azobenzene-functionalized porous polymers for selective CO₂ capture

Many solid adsorbents have been prepared for the CO2 capture. In particular, the photoresponsive adsorbents have attracted extensive interests because of their tunable pore structure and variable responsive behaviors provoked by the external light. However, it is challenging to fabricate the photoresponsive adsorbents featured the big CO(2 )capacity and high CO2 selectivity. Herein, copolymerized between 4-phenylazobenzoyl chloride, 2,4,6-trichloro-1,3,5-triazine and melamine, a series of azobenzene-functionalized porous polymers (PTM-AZOs) are successfully synthesized. The PTM-AZOs are verified in possession of proper pore structures, large surface area and photoconductive properties through a series of characterization. The PTM-AZO-2 with the trans-isomerization exhibits the best CO2 adsorption amount of 2.7 mmol.g(-1) (273 K and 0.1 MPa), while the CO2/N-2 selectivity can reach 2459 and 607 on the trans- and cis-isomerization, respectively. The regulatable pore structures controlled by the photoresponsive azobenzene groups affect the CO2 capture performance of the PTM-AZOs. (C) 2021 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.