Synthesis of well-shaped and high-crystalline Ce-based metal organic framework for CO₂/CH₄ separation

A well-shaped Ce (IV)-based metal organic framework (Ce-BDC) is prepared under solvothermal method. The influence of synthesis time, temperature and the amount of acetic acid (HAc) as a modulator is studied to develop a new strategy for the synthesis of well-shaped Ce-based MOF. The relationship between the synthesis parameters and morphology as well as crystallinity of Ce-BDC is investigated by XRD and SEM. Furthermore, the obtained well-shaped Ce-BDC shows a CO₂ uptake capacity of 2.28 mmol g⁻¹ at 0 °C and 1.0 bar. Meanwhile, the breakthrough curve behaviors of Ce-BDC are investigated for a CO₂/CH₄ and CO₂/N₂ mixture gas. It is found that the Ce-based MOF adsorbs CO₂ under ambient temperature and pressure, but completely excludes CH₄ and N₂, suggesting that it is a promising adsorbent for efficient separation of CO₂ from natural gas.