Pillared-layer ultramicroporous material for highly selective SO2 capture from CO2 mixtures

• CPL-1-NH 2 with high density amino groups and oxygen functional sites shows benchmark SO 2 /CO 2 IAST selectivity 485 in MOFs. • CPL-1-NH 2 is highly-stable and its structure is well retained during cycling SO 2 capture. • The SO 2 capture performance of CPL-1-NH 2 is hardly affected in the presence of CO 2 . Removal of low concentration sulfur dioxide (SO 2 ) from gas mixture is of great significance in gas purification, but the selective recognition of SO 2 from carbon dioxide (CO 2 ) still remains a great challenge with low separation selectivity. Herein, we reported a highly-stable pillared-layer ultramicroporous material CPL-1-NH 2 for efficient separation of SO 2 and CO 2 with benchmark IAST selectivity (4 8 5) in metal organic frameworks (MOFs). The high separation selectivity is attributed to the narrow channel with lined amino groups, which exhibits significantly higher affinity to SO 2 than CO 2 . Even in the presence of CO 2 and trace moisture, the dynamic SO 2 capture performance is hardly affected, demonstrating its great promise for SO 2 capture. Simulation studies were conducted to gain the deep insight into the microscopic adsorption behaviors of SO 2 and CO 2 .