Tuning the Adsorption Selectivity of ZIF‐8 by Amorphization

Amorphous metal–organic frameworks ( a m MOFs) with a partially collapsed structure are a new category of porous hybrid materials. Here, solid‐state amorphization of ZIF‐8 was achieved by mechanical compression at 0.75 GPa. The compression‐induced amorphous ZIF‐8 ( a m ZIF‐8) had a collapsed structure, but retained partial porosity. Benefiting from the deformed channel, the resultant a m ZIF‐8 exhibited preferable adsorption of C 3 H 6 , resulting in higher thermodynamic adsorption selectivity of C 3 H 6 /C 3 H 8 (6.72) than the crystalline counterparts (1.06). Further, a m ZIF‐8 achieved complete separation of an equimolar C 3 H 6 /C 3 H 8 mixture with the first breakthrough of C 3 H 8 . a m ZIF‐8 also displayed an enhancement in CO 2 /N 2 and CO 2 /CH 4 adsorption selectivities. More importantly, a self‐standing a m ZIF‐8 membrane with boundary‐free microstructure was constructed for the first time, and exhibited separation potential for H 2 /CH 4 , CO 2 /N 2 , CO 2 /CH 4 , and C 3 H 6 /C 3 H 8 with ideal selectivities of 14.79, 12.83, 16.23, and 2.67, respectively.