Green and rapid synthesis of hierarchical porous zeolitic imidazolate frameworks for enhanced CO2 capture

Abstract

Two hierarchical porous zeolitic imidazolate frameworks (ZIF-8 and ZIF-90) were synthesized at room temperature and pressure within 60 s using N, N-diethylethanolamine as template. The resulting ZIF-8 showed hierarchically porous structure with micro-, meso-, and macropores together with excellent thermal stability. Furthermore, the porosity properties can be readily tuned by changing the amount of template. The space–time yield (STY) was as high as 1.59 × 104 kg m−3 d−1, which is higher than any previously reports. The introduced template N, N-diethylethanolamine played two roles during the synthesis: one played a protonation agent role enables the ligands deprotonation, the other played a template role served as structure-directing agents (SDAs) of meso- and macropores. The as-syntehszied hierarchical porous ZIF-8 exhibited enhanced adsorption capacity for CO2 capture. This work offers a new direction for the facile synthesis of hierarchical porous ZIFs with high STY.