金属有机框架的蒸气辅助老化法合成及其在此条件下的反应活性研究

In recent decades, the design and synthesis of metal-organic frameworks (MOFs), which have great potential of industrial applications in gas storage and separation, catalysis, magnetic resonance imaging and luminescence, have captured much attention. Compared with the conventional solution-based preparation of MOFs, the vapor-assisted aging (VAG) synthesis is a simpler, more energy-efficient, greener and more readily scale-up preparation method, which is appropriate for being applied in industrial preparation. For the VAG process, we utilize four pre-treatment methods: pre-grinding (pre-G), pre-liquid assisted grinding (pre-LAG), pre-ionic assisted grinding (pre-IAG) and pre-ionic and -liquid assisted grinding (pre-ILAG) to grind starting materials including 27 organic carboxylic acids and transition metal or rare earth oxides/salts. The resulting pre-treated mixtures are then placed in a capped-glass container and exposed in a solvent vapor at room temperature. Further, in order to know the aging process clearly, the changes of particles morphology and the mobility of crude materials in aging, we monitor the reaction by powder X-ray diffraction, SEM and TEM. Additionally the BET surface area and pore analysis of the product MOFs will be conducted to manifest their crystal quality. The VAG reaction will be tried to scale up to yield MOFs in 1000 grams. Finally, we will conclude the relationship between pre-treatment methods, MOFs structures and solvent vapor, to promote VAG to have universal applicability.

金属-有机框架（MOFs）在气体存储及分离、催化、发光、生物医药等领域拥有巨大的潜在应用价值，是近年来化学和材料学科中的研究热点。相对于传统基于溶液法制备MOFs，蒸气辅助老化法是把经过预处理的反应原料在室温下暴露于溶剂蒸气中进行老化，在较短时间内合成具有高结晶度的MOFs。其具有简捷、能耗低、绿色环保和易大量制备的优点，是工业化制备的首选方法。我们选取了27个有机羧酸与过渡、稀土金属氧化物或金属盐混合，经过四种预研磨（预干磨，预湿磨，预盐磨和预盐湿磨）处理后，常温下置于含有溶剂蒸气的密闭容器中，利用粉末X射线衍射和SEM、TEM监测反应进程和微粒形貌及元素分布情况，并对于得到的MOFs产品进行比表面积及孔径分析。最后，研究把制备量放大至上千克级别的蒸气辅助老化合成条件。通过总结蒸气辅助老化法合成MOFs材料的规律，从而指导更多的此类材的开发，使得这种方法具有普遍适用性。

金属-有机框架（MOFs）在气体存储及分离、催化、发光、生物医药等领域拥有巨大的潜在应用价值，是近年来化学和材料学科中的研究热点。相对于传统基于溶液法制备MOFs，蒸气辅助老化法是把经过预处理的反应原料在室温下暴露于溶剂蒸气中进行老化，在较短时间内合成具有高结晶度的MOFs。其具有简捷、能耗低、绿色环保和易大量制备的优点，是工业化制备的首选方法。我们选取了具有代表性的有机羧酸与过渡、稀土金属氧化物或金属盐混合，经过四种预研磨（预干磨，预湿磨，预盐磨和预盐湿磨）处理后，常温下置于含有溶剂蒸气的密闭容器中，利用粉末X射线衍射和SEM、TEM监测反应进程和微粒形貌及元素分布情况，并对于得到的MOFs产品进行比表面积及孔径分析。最后，研究把制备量放大至上百克级别的蒸气辅助老化合成条件。根据大量的实验发现，多数的MOFs（如连接节点为轮状双金属M2(COO)4化合物，连接节点为Zn4O(COO)6构筑单元的IRMOFs系列化合物，沸石咪唑框架（ZIFs）和MIL-101体系都可以通过温和的蒸汽辅助老化法合成得到。而且，我们还研究了MOFs在蒸汽老化条件下的反应活性研究，发现一些MOFs化合物在溶剂蒸汽熏蒸条件下可以发生相互的结构转化。