Monolithic MAF-6 aerogel with hierarchical pore structure for methanol/ethanol separation and Knoevenagel reaction

The synthesis of monolithic MOF aerogel is a critical step in applying MOFs to many practical applications. MAF-6 (RHO-[Zn(eim)2], Heim = 2-ethylimidazole) is a type of MOF materials with large cavities and apertures. However, it has been much less studied due to the difficulty in obtaining it via conventional synthesis protocols. Herein, a nearly pure MAF-6 monolith with macro/meso/microporous pore structure is synthesized in situ by emulsion template method, which exhibits hierarchical structure with high porosity (∼80 %), large specific surface area (up to 1135 m2/g), and excellent mechanical properties. In addition, the monoliths demonstrate excellent capability and stability to separate methanol/ethanol mixtures and high catalytic performance in the Knoevenagel reaction. This work provides an effective approach to prepare MAF-6 monoliths for potential application in catalysis, adsorption, separation, etc.