相对于微孔金属有机骨架化合物,中孔金属有机骨架化合物的研究大大拓宽了该类材料的应用,尤其是在多相催化、挥发性有机物吸附和药物输送等领域。目前存在的问题主要集中在材料制备环节,尽管可以从分子水平设计出具有合适尺寸的中孔金属有机骨架材料,但是会出现合成过程中骨架结构发生贯穿无法得到中孔,甚至样品活化过程中骨架发生坍塌失去中孔等问题。本文综述了中孔金属有机骨架材料的设计策略与制备方法,如使用长配体、混合配体、表面活性剂辅助及后合成修饰等方法,并对各种制备方法的优缺点进行了总结。简要介绍了中孔金属有机骨架材料在气体存储、多相催化、分子传感、挥发性有机物吸附和药物载体等领域的应用进展,最后展望了该材料的发展前景。
Mesoporous metal-organic frameworks (MOFs), comparing with those with micropores, have attracted tremendous attention for expanding their applications in gas storage, heterogeneous catalysis, volatile organic compounds (VOCs) adsorption, drug carrier, etc. Metal-organic frameworks are still largely restricted to the microporous regins to date, with the negative impact of small pore size on the diffusion and mass transfer inside. The development of reliable and reproducible methods to prepare and stabilize mesoporous metal-organic frameworks with tailored structures and tunable properties remains a great challenge to meet many future applications. The structure of materials can be designed on molecular level, but the problem remains that the frameworks tend to interpenetrate one another to maximize packing efficiency or collapse while solvent molecules removed. The preparation and applications of mesoporous metal-organic frameworks are reviewed in this paper. Several preparation approaches, such as combining secondary building units (SBUs) and extended ligands, designing zinc-adeninate octahedral building units with lager size, using long ligands or mixed-ligands, surfactant template to get mesosize channels, cages or pockets are presented in detail, and the advantages and disadvantages of each method are summarized. In addition, applications of mesoporous metal-organic frameworks in the areas of gas storage, catalysis, sensors, adsorption of VOCs and drug carrier are introduced.