Highly Stable Amide-Functionalized Zirconium-Organic Frameworks: Synthesis, Structure, and Methane Storage Capacity
Yu-Feng Zhang, Zong-Hui Zhang, Han Fang, Xin-Ai Guo, Yanan Ma, Yue-Zhong Zhang, Dong‐Xu Xue
Abstract
With the development of crystalline porous materials toward methane storage, the stability issue of metal–organic framework (MOF) materials has caused great concern despite high working capacity. Considering the high stability of zirconium-based MOFs and effective functions of amide groups toward gas adsorption, herein, a series of UiO-66 type of Zr-MOFs, namely, Zr- fcu -H/F/CH 3 /OH, were successfully designed and synthesized by virtue of amide-functionalized dicarboxylate ligands bearing distinct side groups (i.e., −H, −F, −CH 3, and −OH) and ZrCl 4 in the presence of trifluoroacetic acid as the modulator. Single-crystal X-ray diffraction and topology analyses reveal that these compounds are archetypal fcu MOFs encompassing octahedral and tetrahedral cages, respectively. The N 2 sorption isotherms and acid–base stability tests demonstrate that the materials possess not only relatively high surface areas, pore volumes, and appropriate pore sizes but also great hydrolytic stabilities ranging pH = 3–11. Furthermore, the volumetric methane storage working capacities of Zr- fcu -H, Zr- fcu -F, Zr- fcu -CH 3, and Zr- fcu -OH at 298/273 K and 80 bar are 187/217, 175/193, 167/187, and 154/171 cm 3 (STP) cm –3, respectively, which indicate that the zirconium-based crystalline porous materials are capable of storing relatively high amounts of methane.