Hierarchically Porous Metal-Organic Frameworks: Green Synthesis and High Space-Time Yield

Two major goals of hierarchically porous metal-organic frameworks (HP-MOFs) research are the reduction of energy consumption and the enhancement of production rate. Here, we develop a simple and versatile method for the rapid synthesis of three HP-MOFs (Cu-BTC, Cu-BDC, and ZIF-8) through introducing zinc oxide (ZnO) and template simultaneously. The synthesis condition was facile, and the synthesis time could be shortened to 30 min. Moreover, the porosity and morphology of HP-MOFs could be adjustable with variable amounts and types of template. A synergistic effect of the hydroxy double salt (HDS) and template is crucial for the synthesis, whereas no meso- and macropores were formed in the individual employing of either the HDS or the template. The rapid synthesis mechanism was further elucidated by the mesoscopic dynamics simulation. Furthermore, the synthetic approach of HP-MOFs was readily scalable with a space-time yield (STY) of up to 1322 kg.m(-3).d(-1), which allowed the large-scale production. The prepared HP-MOFs exhibited improved catalytic activity as compared with microporous MOFs for the Henry reaction involving large molecules. This synthetic route with low energy consumption and high production rate may open a door for the large-scale production and a wide range of application of HP-MOFs.