Facile microwave-assisted solvothermal synthesis of rod-like aluminum terephthalate [MIL-53(Al)] for CO2 adsorption

To alleviate environment issues derived from CO2 emission, developing effective and economical methods for CO2 capture has attracted much attention for decades. Metal-organic frameworks possess high porosity and stability, which is favorable to the adsorption of small molecules. Herein, an aluminum-based MOF, aluminum terephthalate [MIL-53(Al)], was synthesized with H2O and N,N′-dimethylformamide as co-solvent via microwave-assisted method for CO2 adsorption. The parameters including pre-mixing mode, microwave temperature, microwave power and reaction time were varied to study their influences on crystal structure, morphology and CO2 adsorption capacity of MW-MIL-53(Al). Wherein, MW-MIL-53(Al) prepared with pre-mixing mode of stirring at 130 °C, 200 W and 3 h presents high crystallinity and rod-like morphology. The synthesized MW-MIL-53(Al) possesses relatively high BET surface area (961 m2/g), pore volume (0.46 cm3/g) and thermal stability (up to 480 °C), and its CO2 adsorption capacity is 2.16 mmol CO2/g adsorbent under 25 °C and 0.1 MPa, which is higher than CS-MIL-53(Al) synthesized via conventional solvothermal method at 130 °C for 48 h.