美国加州大学Omar M. Yaghi团队报道了改善大气水收集的金属-有机框架中水结构的演变。相关研究成果发表在2021年10月22日出版的《科学》。

尽管水客体在多孔晶体中的位置可以确定，但其填充顺序的确定仍然具有挑战性。

研究人员通过进行一系列单晶x射线衍射测量和密度泛函理论计算，解释了最先进的集水金属有机骨架MOF-303的充水机理。第一个水分子与极性有机连接物紧密结合；然后是额外的水分子形成孤立的团簇，然后是团簇链，最后是水网络。水结构的这种演变导致其通过多元方法修改孔隙，从而精确调节第一个水分子的结合强度，并有意塑造吸水行为。从而导致了更高的水生产率，以及再生温度和焓的可调性，而不会影响容量和稳定性。

附：英文原文

Title: Evolution of water structures in metal-organic frameworks for improved atmospheric water harvesting

Author: Nikita Hanikel, Xiaokun Pei, Saumil Chheda, Hao Lyu, WooSeok Jeong, Joachim Sauer, Laura Gagliardi, Omar M. Yaghi

Issue&Volume: 2021-10-22

Abstract: Although the positions of water guests in porous crystals can be identified, determination of their filling sequence remains challenging. We deciphered the water-filling mechanism for the state-of-the-art water-harvesting metal-organic framework MOF-303 by performing an extensive series of single-crystal x-ray diffraction measurements and density functional theory calculations. The first water molecules strongly bind to the polar organic linkers; they are followed by additional water molecules forming isolated clusters, then chains of clusters, and finally a water network. This evolution of water structures led us to modify the pores by the multivariate approach, thereby precisely modulating the binding strength of the first water molecules and deliberately shaping the water uptake behavior. This resulted in higher water productivity, as well as tunability of regeneration temperature and enthalpy, without compromising capacity and stability.

DOI: abj0890

Source: https://www.science.org/doi/10.1126/science.abj0890