Tuning the Adsorption Selectivity of ZIF-8 by Amorphization |
| |
Authors: | Qiang Ma Dr. Hua Jin Prof. Dr. Yanshuo Li |
| |
Affiliation: | School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211 P. R. China |
| |
Abstract: | Amorphous metal–organic frameworks (amMOFs) 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 (amZIF-8) had a collapsed structure, but retained partial porosity. Benefiting from the deformed channel, the resultant amZIF-8 exhibited preferable adsorption of C3H6, resulting in higher thermodynamic adsorption selectivity of C3H6/C3H8 (6.72) than the crystalline counterparts (1.06). Further, amZIF-8 achieved complete separation of an equimolar C3H6/C3H8 mixture with the first breakthrough of C3H8. amZIF-8 also displayed an enhancement in CO2/N2 and CO2/CH4 adsorption selectivities. More importantly, a self-standing amZIF-8 membrane with boundary-free microstructure was constructed for the first time, and exhibited separation potential for H2/CH4, CO2/N2, CO2/CH4, and C3H6/C3H8 with ideal selectivities of 14.79, 12.83, 16.23, and 2.67, respectively. |
| |
Keywords: | amorphous ZIF-8 boundary-free microstructures gas separation pressure-induced amorphization self-standing membranes |
|
|