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

Abstract

AbstractHierarchically 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 × 104 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.