Construction of Hierarchically Porous Metal-Organic Frameworks via A Novel Metal Ion-Modulation Approach: A Complementary Approach to Linker-Modulation

Hierarchically porous metal-organic frameworks (HP-MOFs) always present novel and advanced performances in many applications. Herein, we demonstrated a novel mechanochemical metal modulation strategy to construct the HP-MOFs. The metal modulator bearing different coordination ability from the parent metal was incorporated into the parent metal precursor via ball milling. Then, by reacting with the ligand, the metal modulator interrupted the original metal-ligand coordination and created the defect-mesopores during the solid-state transformation process, resulting in HP-MOF. Using this approach, a series of HP-MOFs were constructed. Notably, unlike the linker modulation approach, the missing-linker defects are no longer the dominant defects in these prepared HP-MOFs. Beyond this, the metal modulators can be co-assembled into the HP-MOFs, functionalizing HP-MOFs with new metal active sites. Finally, the catalytic performances of prepared hierarchically porous ZIF-8-Pd was tested, it presented superior catalytic activities towards hydrogenation of unsaturated aldehydes.