Effective enhancement of selectivities and capacities for CO 2 over CH 4 and N 2 of polymers of intrinsic microporosity via postsynthesis metalation

A series of metalized C‐PIM‐M (M = Na + , Mg 2+ , Al 3+ , PIMs = polymers of intrinsic microporosity) materials were prepared from a carboxyl‐functionalized PIM (C‐PIMs). The C‐PIM‐Na exhibited a high CO 2 adsorption capacity of 2.44 mmol/g and extreme low CH 4 uptake of 0.28 mmol/g at 273 K and 101 kPa among three metallated PIMs. It showed remarkably high CO 2 /CH 4 and CO 2 /N 2 selectivities at both 273 and 293 K due to an advantageous pore‐blocking effect of Na + cation.