Boosting SO2/CO2 separation with self-enhanced SO2 adsorption in a microporous metal-organic framework

Sulfur dioxide (SO2) stands out as a significant air pollutant, possessing the capacity to present considerable risks to human health. Governments worldwide have implemented strict regulations on emissions from industries. Separating SO2 and CO2 is essential for compliance with environmental standards, avoiding penalties, and promoting sustainable practices. Herein, we report a microporous metal–organic framework, CPL-11, which demonstrates a self-enhanced SO2 adsorption mechanism, significantly improving SO2/CO2 separation efficiency. Under the conditions of 0.1 bar and 298 K, CPL-11 exhibits an impressive SO2 adsorption capacity of 4.46 mmol g−1. Furthermore, at 1 bar and 298 K, CPL-11 exhibits a remarkable IAST selectivity for SO2/CO2, reaching a value of 132. This noteworthy enhancement in adsorption capacity and selectivity underscores the potential of CPL-11 as an effective material for addressing challenges related to SO2 capture and separation in gas mixtures. Theoretical calculations reveal that the outstanding performance of CPL-11 can be attributed to the synergistic interplay of host–guest interactions and guest–guest interactions. This unique mechanism holds promise for advancing the field of gas separation technology and contributing to a cleaner and healthier environment.