High-throughput CO₂ capture using PIM-1@MOF based thin film composite membranes

Carbon capture from power plants represents a powerful technique to mitigate increasing greenhouse gas emissions. In this work, we describe a thin film composite (TFC) membrane incorporating a polymer of intrinsic microporosity (PIM-1) and metal organic framework (MOF) nanoparticles for post-combustion CO₂ capture. The novel TFC membrane design consists of three layers: (1) a CO₂ selective layer composed of a PIM-1@MOF mixed matrix; (2) an ultrapermeable PDMS gutter layer doped with MOF nanosheets; and (3) a porous polymeric substrate. Notably, the PDMS@MOF gutter layer incorporating amorphous nanosheets provides a CO₂ permeance of 10,000–11,000 GPU, suggesting less gas transport resistance in comparison with pristine PDMS gutter layers. In addition, by blending nanosized MOF particles (MOF-74-Ni and NH₂-UiO-66) into PIM-1 to afford a selective layer, the resultant TFC membrane assembly delivered improved CO₂ permeance of 4660–7460 GPU and CO₂/N₂ selectivity of 26–33, compared with a pristine PIM-1 counterpart (CO₂ permeance of 4320 GPU and CO₂/N₂ selectivity of 19). Furthermore, PIM-1@MOF based TFC membranes displayed an enhanced resistance to aging effect, maintaining a stable CO₂ permeance of 900–1200 GPU and CO₂/N₂ selectivity of 26–30 after aging for 8 weeks. To the best of our knowledge, the high CO₂ separation performance presented here is unprecedented for PIM-1 based TFC membranes reported in the open literature.