CO ₂ Capture by Hydroxylated Azine‐Based Covalent Organic Frameworks

Covalent organic frameworks (COFs) RIO-13, RIO-12, RIO-11, and RIO-11m were investigated towards their CO2 capture properties by thermogravimetric analysis at 1 atm 40 °C. These microporous COFs bear in common the azine backbone composed of hydroxy-benzene moieties but differ relative number hydroxyl groups present each material. Thus, sorption capacities studied as a function textural chemical properties. Their maximum uptake values showed strong correlation with an increasing specific surface area, that property alone could not fully explain data. Hence, uptake, combined DFT calculations, indicated COF acts adsorption threshold, indeed identified relevant sites all COFs. Additionally, best performing was thoroughly investigated, experimentally theoretically, for its variety concentrations temperatures, excellent isothermal recyclability up to 3 cycles.