Synthetic approaches for the incorporation of free amine functionalities in porous coordination polymers for enhanced CO2 sorption

Encapsulation of a Porous Organic Cage into the Pores of a Metal–Organic Framework for Enhanced CO2 Separation

“…The lower Q st 0 value of the CO 2 adsorption on CB6@MIL‐101 in comparison to pure MIL‐101 might be caused by the “sheltering effect”, which makes some coordinative unsaturated sites (CUSs) unavailable to CO 2 . Nevertheless, this is compensated for by CB6 offering more affinity sites and micropores for CO 2 , which led to the enhanced uptake up to 1 bar at 293 K. The CO 2 uptake capacity of these composites is comparable or even higher than that of some amine/polyamine‐modified MIL‐101 materials (Table S4) . The strong sorption of CO 2 in CB6@MIL‐101 was also confirmed in an FT‐IR spectroscopic study.…”

Encapsulation of a Porous Organic Cage into the Pores of a Metal–Organic Framework for Enhanced CO2 Separation

“…This can be traced back to the enhanced composite affinity towards CH 4 based on the Q st 0 values of 18.1,19.6,24.2,25.6,CB6,29,36), respectively ( Figure S25 b). Nevertheless,the composites still exhibited an increased CO 2 /CH 4 selectivity for aC O 2 /CH 4 mixture (2:98) at 1.0 bar over the individual components.T he IAST selectivities for CB6, 29,36) were found to be 12.7, 17, 20, 27, and 29 at 293 Ka nd 1.0 bar ( Figure S25 d). To further confirm this superiority of the CB6@MIL-101 composites,we fabricated MMMs [15] of 16 wt %C B6, MIL-101, and CB6@MIL-101-36 in Matrimid as the polymer matrix (Figure S34).…”

“…To simulate flue gas conditions,wecalculated the CO 2 /N 2 selectivities for CB6, 29,36) from the N 2 and CO 2 adsorption isotherms using ideal adsorbed solution theory (IAST) for aC O 2 /N 2 mixture (15:85) at 293 K ( Figure 3d and Figure S23). Forp ostcombustion CO 2 capture,p orous sorbents should have both high CO 2 uptake capacities (in the low P/P 0 region) and high CO 2 /N 2 selectivity.T he IAST values for MIL-101, CB6, and CB6@MIL-101-W (W = 19, 29, 36) were determined to be 19,70,31,58, and 108 at 293 K, respectively.The encapsulation of CB6 into MIL-101 allowed us to introduce CO 2 selectively because of the intrinsic micropores of CB6 and the retained micropores of MIL-101, while losing some of the uptake capacity of the non-selective mesopores of MIL-101.…”

“…TheC H 4 sorption and CO 2 /CH 4 selectivity investigation of CB6, 29,36; Figure S25 and Table S2) indicated as lightly enhanced CH 4 sorption for the composite compared with CB6 and MIL-101. This can be traced back to the enhanced composite affinity towards CH 4 based on the Q st 0 values of 18.1,19.6,24.2,25.6,CB6,29,36), respectively ( Figure S25 b).…”

“…TheC H 4 sorption and CO 2 /CH 4 selectivity investigation of CB6, 29,36; Figure S25 and Table S2) indicated as lightly enhanced CH 4 sorption for the composite compared with CB6 and MIL-101. This can be traced back to the enhanced composite affinity towards CH 4 based on the Q st 0 values of 18.1,19.6,24.2,25.6,CB6,29,36), respectively ( Figure S25 b). Nevertheless,the composites still exhibited an increased CO 2 /CH 4 selectivity for aC O 2 /CH 4 mixture (2:98) at 1.0 bar over the individual components.T he IAST selectivities for CB6, 29,36) were found to be 12.7, 17, 20, 27, and 29 at 293 Ka nd 1.0 bar ( Figure S25 d).…”