Morelli Venturi Diletta, Sole Notari Maria, Trovarelli Letizia, Mosconi Edoardo, Alothman Asma A, Molokova Anastasia, Ruser Niklas, Meier Christoph, Achenbach Bastian, Lomachenko Kirill A, Del Giacco Tiziana, Costantino Ferdinando, Stock Norbert
Institute of Inorganic Chemistry, Christian-Albrecht University of Kiel, Max-Eyth-Straße 2, 24118, Kiel, Germany.
Kiel Nano, Surface and Interface Science KiNSIS, Christian-Albrecht University of Kiel, Christian-Albrechts-Platz 4, 24118, Kiel, Germany.
Chemistry. 2024 Jun 3;30(31):e202400433. doi: 10.1002/chem.202400433. Epub 2024 Apr 29.
Cerium-based Metal-Organic frameworks (Ce-MOFs) are attracting increasing interest due to their similar structural features to zirconium MOFs. The redox behavior of Ce(III/IV) adds a range of properties to the compounds. Recently, perfluorinated linkers have been used in the synthesis of MOFs to introduce new characteristic into the structure. We report the synthesis and structural characterization of Ce(IV)-based MOFs constructed using two perfluorinated alkyl linkers. Their structure, based on hexanuclear CeO(OH) clusters linked to each other by the dicarboxylate ions, has been solved ab-initio from X-ray powder diffraction data and refined by the Rietveld method. The crystallization kinetics and the MOF formation mechanism was also invesitigated by Synchrotron radiation with XAS spectroscopies (EXAFS and XANES). The MOFs present the same fcu cubic topology as observed in MOF-801 and UiO-66, and they showed good stability in water at different pH conditions. The electronic structure of these MOFs has been studied by DFT calculations in order to obtain insights into the density of states structure of the reported compounds, resulting in band gaps in the range of 2.8-3.1 eV. Their catalytic properties were tested both thermally and under visible light irradiation for the degradation of methyl orange (MO) dye.
基于铈的金属有机框架材料（Ce-MOFs）因其与锆基MOFs相似的结构特征而受到越来越多的关注。Ce(III/IV)的氧化还原行为为这些化合物增添了一系列性质。最近，全氟连接体已被用于MOFs的合成中，以便将新特性引入其结构。我们报道了使用两种全氟烷基连接体构建的基于Ce(IV)的MOFs的合成及结构表征。它们的结构基于通过二羧酸根离子相互连接的六核CeO(OH)簇，已根据X射线粉末衍射数据从头解析，并通过Rietveld方法进行了精修。还利用同步辐射X射线吸收光谱（EXAFS和XANES）研究了其结晶动力学和MOF形成机理。这些MOFs呈现出与MOF-801和UiO-66中观察到的相同的面心立方拓扑结构，并且在不同pH条件下的水中表现出良好的稳定性。为了深入了解所报道化合物的态密度结构，通过密度泛函理论（DFT）计算研究了这些MOFs的电子结构，结果显示其带隙在2.8 - 3.1 eV范围内。对它们的催化性能进行了热催化和可见光照射下催化降解甲基橙（MO）染料的测试。
