A Triphasic Modulated Hydrothermal Approach for the Synthesis of Multivariate Metal–Organic Frameworks with Hydrophobic Moieties for Highly Efficient Moisture‐Resistant CO 2 Capture

The CO 2 capture performance of metal–organic frameworks (MOFs) is largely compromised under wet conditions. This study reports a triphasic modulated hydrothermal approach to prepare multivariate (MTV) UiO‐66(Zr) MOFs with hydrophobic moieties for wet CO 2 capture under heterogeneous aqueous conditions. Among these MOFs, UiO‐66(Zr)‐NH 2 ‐F 4 ‐0.53 shows a binary CO 2 adsorption capacity of 0.76 mmol g −1 and a CO 2 /N 2 (15/85) selectivity of 18.9 at 298 K, which is among the best of all UiO‐66‐type MOFs. Besides, UiO‐66(Zr)‐NH 2 ‐F 4 ‐0.53 only loses 30% of its CO 2 uptake capacity under wet (70% relative humidity) CO 2 /N 2 (15/85) mixture condition at 298 K, compared with almost 100% loss of zeolite materials and other hydrophilic adsorbents under similar conditions. This moisture‐resistant feature makes UiO‐66(Zr)‐NH 2 ‐F 4 ‐0.53 one of the best physisorption‐based adsorbent materials for CO 2 capture under wet conditions so far. Moreover, UiO‐66(Zr)‐NH 2 ‐F 4 ‐0.53 demonstrates enhanced breakthrough dynamics with less cross‐column pressure drop ( ΔP ≈ 0 bar) and 2.7 times larger mass transfer coefficient ( k = 0.1235 s −1 ) than that of pristine UiO‐66(Zr)‐NH 2 ( ΔP ≈ 0.25 bar, k = 0.0334 s −1 ). The present study offers new insights into the heterogeneous synthesis of MTV‐MOFs and a paradigm to design hydrophobic MOFs with improved material features for moisture‐resistant CO 2 capture applications.