Synthesis of Hierarchically Structured Metal - Organic Frameworks by a Dual-Functional Surfactant

Hierarchically structured metal - organic frameworks (H- MOFs) are of great importance because of their widespread applicability in gas storage, separation, and catalysis. However, the synthesis of H-MOFs with tunable porosity and high stability is still a tremendous challenge. Herein, two strategies are developed to prepare classical porous MOFs-hierarchically structured HKUST - 1 (H-HKUST - 1): (1) through utilizing a dual-functional surfactant as a template individually, H-HKUST - 1 was successfully synthesized in a solvothermal system. The obtained H-HKUST-1 products possess well-ordered mesopores together with high thermal stability, the porosity of H-HKUST - 1 depends on the amount of the template and the type of extraction solvents. The multi-ammonium head of the introduced surfactant bonded with BTC3- anion to form the main framework while the long alkyl chain filled the space to form mesopores. (2) H-HKUST - 1 was also prepared rapidly at room temperature and ambient pressure through the simultaneous addition of a dual-functional surfactant and zinc oxide (ZnO). The synthesis time was only 1 min, with a space-time yield (STY) for the as-synthesized H-HKUST - 1 as high as 3.1 x 10(4) kg.m(-3).d(-1), which is at least one order of magnitude higher than previously reported results. The present approach opens up new avenues for the templated synthesis of stable H - MOFs with tunable porosity and high stability for a wide range of applications.