Tailoring Amine-Functionalized Ti-MOFs via a Mixed Ligands Strategy for High-Efficiency CO<sub>2</sub> Capture

oleh: Yinji Wan, Yefan Miao, Tianjie Qiu, Dekai Kong, Yingxiao Wu, Qiuning Zhang, Jinming Shi, Ruiqin Zhong, Ruqiang Zou

Format: Article
Diterbitkan: MDPI AG 2021-12-01

Deskripsi

Amine-functionalized metal-organic frameworks (MOFs) are a promising strategy for the high-efficiency capture and separation of CO<sub>2</sub>. In this work, by tuning the ratio of 1,3,5-benzenetricarboxylic acid (H<sub>3</sub>BTC) to 5-aminoisophthalic acid (5-NH<sub>2</sub>-H<sub>2</sub>IPA), we designed and synthesized a series of amine-functionalized highly stable Ti-based MOFs (named MIP-207-NH<sub>2</sub>-<i>n</i>, in which <i>n</i> represents 15%, 25%, 50%, 60%, and 100%). The structural analysis shows that the original framework of MIP-207 in the MIP-207-NH<sub>2</sub>-<i>n</i> (<i>n</i> = 15%, 25%, and 50%) MOFs remains intact when the mole ratio of ligand H<sub>3</sub>BTC to 5-NH<sub>2</sub>-H<sub>2</sub>IPA is less than 1 to 1 in the resulting MOFs. By the introduction of amino groups, MIP-207-NH<sub>2</sub>-25% demonstrates outstanding CO<sub>2</sub> capture performance up to 3.96 and 2.91 mmol g<sup>−1</sup>, 20.7% and 43.3% higher than those of unmodified MIP-207 at 0 and 25 °C, respectively. Furthermore, the breakthrough experiment indicates that the dynamic CO<sub>2</sub> adsorption capacity and CO<sub>2</sub>/N<sub>2</sub> separation factors of MIP-207-NH<sub>2</sub>-25% are increased by about 25% and 15%, respectively. This work provides an additional strategy to construct amine-functionalized MOFs with the maintenance of the original MOF structure and high performance of CO<sub>2</sub> capture and separation.