MIL-53(Al) mesostructured metal-organic frameworks

Hierarchically mesostructured metal-organic frameworks (designated here as L-MOFs) were designed and synthesized using block copolymers (P123 and F127) as structure directing agents under solvothermal synthesis conditions. Porous mesostructure of L-MOF materials was established from nitrogen adsorption–desorption isotherms (BET) at 77 K, high-resolution transmission electron micrograps (HRTEM), and small-angle X-ray diffraction (SAXD) patterns. MOF crystal structures were characterized by wide-angle X-ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FTIR). Results demonstrated that L-MOF materials have well-defined trimodal pore size distributions showing micro-, and simultaneous existence of up to two mesopore channel systems. L-MOF materials have two kinds of mesoporous phases: one has disordered wormhole-like structure with pore size diameter around 4 nm, and the other one, only appearing in L-MOF(1) and L-MOF(2) (corresponding to P123 and F127), has a needle-like shape with BJH pore sizes are of 7.6 and 5.4 nm, respectively.