Amine-grafted MIL-101(Cr) and Cu-BTC via post-synthetic modification for synergistic enhancement of CO2 uptake

Carbon capture and storage (CCS) has been recognized as an important technology for CO2 removal in recent years to achieve carbon neutrality goals. In this work, the structure and CO2 adsorption properties of MOFs (Metal organic frameworks) modified with different types and amounts of amine groups were systematically investigated by loading organic amine molecules onto the skeleton of original materials through the method of post-synthesis modification of MOFs, which used MIL-101 (Cr) and Cu-BTC as the base materials. Compared with the unmodified materials, the organic amine-modified composites have excellent CO2 adsorption properties, especially after the introduction of EDA (ethylenediamine) into the MOFs, the CO2 adsorption of MIL-101(Cr) and Cu-BTC can reach 1052 mg/g and 510 mg/g, respectively, which greatly improves the adsorption of CO2. Meanwhile, the CO2 adsorption performance of the materials was investigated by taking the temperature and the amount of organic amine as variables, and it was found that both the temperature and the amount of organic amine would affect the CO2 adsorption to a certain extent.