H2 storage in isostructural UiO-67 and UiO-66 MOFs
H2 storage in isostructural UiO-67 and UiO-66 MOFs
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DOI：
10.1039/c1cp23434j
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发表时间：
2012-01-01
影响因子：
3.3
通讯作者：
Bordiga, Silvia
中科院分区：
文献类型：
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作者：
Chavan, Sachin;Vitillo, Jenny G.;Bordiga, Silvia
最近发现的UiO-66/67/68类同构金属有机骨架（MOFs）[J. H. Cavka等人，J. Am.化学会，2008，130，13850]由于其在高温、高压下以及在不同溶剂、酸和碱存在下的显著稳定性[L. Valenzano等人，Chem.Mater.，2011，23，1700]。UiO-66是通过将Zr 6 O 4（OH）（4）无机基石与作为连接剂的1，4-苯二甲酸酯（BDC）连接得到的立方MOF，其已经在几个实验室中成功地复制。在这里，我们报告了第一个完整的结构，振动和电子特性的同构UiO-67材料，获得使用较长的4，4 '-联苯二羧酸酯（BPDC）连接，通过结合实验室XRPD，Zr K-边EXAFS，TGA，FTIR和UV-Vis研究。在B3 LYP理论水平上进行的实验和周期性计算之间的比较可以充分了解材料的结构，振动和电子特性。这两种材料都在高压和液氮温度下进行了分子氢储存测试。在这方面，使用较长的配体具有双重益处：（i）它降低了材料的密度，以及（ii）它将朗缪尔表面积从1281增加到2483 m2·g（-1），并且将朗缪尔体积从0.43增加到0.85 cm 3·g（-1）。因此，在38巴和77 K下的H-2吸收从UiO-66的2.4质量%增加到新UiO-67材料的4.6质量%。该值是迄今为止报道的最高值之一，但低于在类似压力和温度条件下MIL-101、IRM 0 F-20和M0 F-177报道的那些值（分别为6.1、6.2和7.0质量%）[A. G. Wong-Foy等人，J. Am.化学会，2006，128，3494; M.丁卡和J. R.久了Angew.化学成分：国际版：2008，47，6766]。然而，UiO-67的显著化学和热稳定性以及其结构中不含Cr将使该材料具有竞争力。
The recently discovered UiO-66/67/68 class of isostructural metallorganic frameworks (MOFs) [J. H. Cavka et al. J. Am. Chem. Soc., 2008, 130, 13850] has attracted great interest because of its remarkable stability at high temperatures, high pressures and in the presence of different solvents, acids and bases [L. Valenzano et al. Chem. Mater., 2011, 23, 1700]. UiO-66 is obtained by connecting Zr6O4(OH)(4) inorganic cornerstones with 1,4-benzene-dicarboxylate (BDC) as linker resulting in a cubic MOF, which has already been successfully reproduced in several laboratories. Here we report the first complete structural, vibrational and electronic characterization of the isostructural UiO-67 material, obtained using the longer 4,4'-biphenyl-dicarboxylate (BPDC) linker, by combining laboratory XRPD, Zr K-edge EXAFS, TGA, FTIR, and UV-Vis studies. Comparison between experimental and periodic calculations performed at the B3LYP level of theory allows a full understanding of the structural, vibrational and electronic properties of the material. Both materials have been tested for molecular hydrogen storage at high pressures and at liquid nitrogen temperature. In this regard, the use of a longer ligand has a double benefit: (i) it reduces the density of the material and (ii) it increases the Langmuir surface area from 1281 to 2483 m(2) g(-1) and the micropore volume from 0.43 to 0.85 cm(3) g(-1). As a consequence, the H-2 uptake at 38 bar and 77 K increases from 2.4 mass% for UiO-66 up to 4.6 mass% for the new UiO-67 material. This value is among the highest values reported so far but is lower than those reported for MIL-101, IRMOF-20 and MOF-177 under similar pressure and temperature conditions (6.1, 6.2 and 7.0 mass%, respectively) [A. G. Wong-Foy et al. J. Am. Chem. Soc., 2006, 128, 3494; M. Dinca and J. R. Long. Angew. Chem., Int. Ed., 2008, 47, 6766]. Nevertheless the remarkable chemical and thermal stability of UiO-67 and the absence of Cr in its structure would make this material competitive.