Hierarchically porous metal–organic frameworks with single-crystal structures and their enhanced catalytic properties

Abstract

Stable hierarchically porous metal–organic frameworks (HP-MOFs) have been successfully prepared under hydrothermal conditions using an anionic surfactant (sodium dodecylbenzene sulfonate, SDBS) as a template. The resultant HP-MOF products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption isotherms, pore size distributions, and thermogravimetric analysis. The structural characterization indicated that the as-synthesized HP-MOFs were single crystals with ordered meso-microporous structures and high stability. Furthermore, the porosities of the HP-MOFs can be systematically tuned by varying the amount of the template. In addition, the phase transformation of template SDBS was investigated using the mesoscopic dynamics (MesoDyn) simulation method, which directly discloses the synthesis mechanism of HP-MOFs for the first time. Due to the improved accessibility and shortened diffusion routes, the prepared HP-MOFs exhibited a clear advantage in catalyzing Henry reaction involving bulky-molecules compared with their conventional counterpart. Such HP-MOFs with uniform mesopores and excellent stability have great potential in catalysis involving bulky molecules.