Synthesis of MOF-199 and application to CO2 adsorption

Thuy Van Nguyen Thi, Cam Loc Luu, Tien Cuong Hoang, Tri Nguyen, Thanh Huong Bui, Phuc Hoang Duy Nguyen and Thuy Phuong Pham Thi

Abstract

In this study a metal-organic framework (MOF-199) has been synthesized by solvent-thermal method. The conditions of preparation and activation processes have been investigated. The obtained material was characterized by methods of x-ray diffraction (XRD), infrared (IR) spectroscopy, thermogravimatric analysis (TGA) and scanning electron microscopy (SEM). The CO₂ adsorption measurements were carried out on a high pressure volumetric analyzer (Micromeritics HPVA − 100). According to experimental results, Cu(NO₃)₂3H₂O has been shown to be the best copper(II) precursor for the synthesis of MOF-199 and N,N-dimethylformamide (DMF):C₂H₅OH:H₂O with the ratio of 1:1:1 has been chosen as the most suitable solvent. The appropriate activation condition has been determined as follows: activate at 200 °C for 5 h and use CH₃OH as the solvent to remove DMF. At the optimal conditions, an octahedral shape and three-dimensional (3D) structure of crystallite of MOF-199 was obtained. The synthesized MOF-199 expressed a high value of specific surface area (1448 m² g⁻¹ by Brunauer–Emmet–Teller (BET) method and 2028 m² g⁻¹ by Langmuir method) with Ta porous size of crystal of 11.8 Å and specific volume of 0.693 cm³ g⁻¹; it was still stable up to 332 °C and its CO₂ storage capacity reached to 206.59 cm³ (STP) g⁻¹ at 25.76 bar