Rapid synthesis of metal-organic framework CALF-20 in H2O/methanol solution under room temperature and normal pressure

In this study, a new process to synthesize Calgary framework 20 (CALF -20), a zinc -based metal -organic framework (MOF), in a H 2 O/methanol solution was developed, exhibiting a high CO 2 adsorption capacity. Generally, CALF -20 was synthesized by a solvothermal method, requiring the consumption of considerable thermal energy. On the other hand, the proposed synthetic process required only 6 min to crystallize CALF -20 in a H 2 O/methanol mixed solution at room temperature (298 K) and normal pressure (101.3 kPa). In addition, CALF -20 was obtained in 93.3 % yield using zinc and oxalate sources under an aging time of 120 min. As -synthesized CALF -20 exhibited a Brunauer - Emmett - Teller surface area of 520 m 2 g -1 , a micropore volume of 0.19 cm 3 g -1 , a CO 2 uptake of 3.84 mmol g -1 at 298 K, and a P CO 2 of 100 kPa; these values were similar to those obtained for CALF20 synthesized by the solvothermal method using high thermal energy. Furthermore, CALF -20 was crystallized without washing using H 2 O. The key factor for the crystallization of the CALF -20 structure in this process was the deprotonation of 1,2,4triazole, which was caused by the acetate anion derived from zinc acetate as the starting metal source.