Confining the Node Accessibility of Zr‐MOFs Along One‐Dimensional Channels Toward High Water‐Vapor Cycle‐Stability

Abstract

AbstractZirconium‐based MOFs (Zr‐MOFs) with high hydrolytic stability are promising materials for water‐adsorption‐related applications. However, besides hydrolytic stability, cycling stability is also a crucial feature that renders a MOF a good candidate for water adsorption. Through a series of Zr‐MOFs with one‐dimensional (1D) channels showing high water cycling stability, a principle of confining the accessibility of Zr6 nodes aligning along channel direction in Zr‐MOFs was unveiled. According to this principle, several topologies that regulates Zr6 nodes with chelating formate aligning in a same plane with a distance less than 5.4 Å can successfully hinder the introduction of in‐plane water molecules, thus significantly improve the cycling stability of Zr‐MOFs for water adsorption. Along with this principle, we illustrated a linker designing strategy by horizontal extending the core of organic linkers toward the synthesis of Zr‐MOFs with similar node alignment. By either intentionally shortening or elongating the core horizontally, both MOFs shows high water‐vapor cycling stability. Among them, NJTech‐5 (NJTech for Nanjing Tech University) with scu‐topology, presents a water uptake capacity of 0.93 g g−1 and working capacity of 0.82 g g−1, making it among the top stable MOFs with high water uptake capacity and a promising candidate for indoor humidity control.