A Moisture‐Stable 3D Microporous CoII‐Metal–Organic Framework with Potential for Highly Selective CO₂ Separation under Ambient Conditions

Selective adsorption and separation of CO 2 from flue gas and landfill gas mixtures have drawn great attention in industry. Porous MOF materials are promising alternatives to achieve such separations; however, the stability in the presence of moisture must be taken into consideration. Herein, we have constructed a microporous metal–organic framework (MOF) {[Co(OBA)(L) 0.5 ] ⋅ S} n ( IITKGP‐8 ), by employing a V‐shaped organic linker with an azo‐functionalized N,N′ spacer forming a 3D network with mab topology and 1D rhombus‐shaped channels along the crystallographic ‘ b’ axis with a void volume of 34.2 %. The activated MOF reveals a moderate CO 2 uptake capacity of 55.4 and 26.5 cm 3 g −1 at 273 and 295 K/1 bar, respectively, whereas it takes up a significantly lower amount of CH 4 and N 2 under similar conditions and thus exhibits its potential for highly selective sorption of CO 2 with excellent IAST selectivity of CO 2 /N 2 (106 at 273 K and 43.7 at 295 K) and CO 2 /CH 4 (17.7 at 273 K and 17.1 at 295 K) under 1 bar. More importantly, this MOF exhibits excellent moisture stability as assessed through PXRD experiments coupled with surface area analysis.