Doping Metal-Organic Frameworks for Water Oxidation, Carbon Dioxide Reduction, and Organic Photocatalysis
Doping Metal-Organic Frameworks for Water Oxidation, Carbon Dioxide Reduction, and Organic Photocatalysis
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DOI：
10.1021/ja203564w
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发表时间：
2011-08-31
影响因子：
15
通讯作者：
Lin, Wenbin
中科院分区：
文献类型：
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作者：
Wang, Cheng;Xie, Zhigang;Lin, Wenbin
采用混合-匹配合成策略将具有催化活性的Ir、Re和Ru二羧酸配合物H2 L1-H2 L 6引入到高度稳定的多孔Zr 6 O 4（OH）（4）（bpdc）（6）（UiO-67，bpdc =对联苯二羧酸）骨架中。bpdc和L-1-L-6配体之间的匹配配体长度允许构建掺杂有L-1-L-6配体的高度结晶的U10 -67骨架（金属有机骨架（MOF）1-6）。如粉末X射线衍射（PXRD）所示，M0 F 1-6与母体Ui 0 -67骨架同构，并且表现出范围为1092至1497 m2/g的高表面积。MOFs 1-6在高达400摄氏度的空气中是稳定的，并且在与太阳能利用相关的一系列反应中是活性催化剂。含有[Cp*Ir-III（dcpy）Cl]（H2L1）、[Cp*Ir-III（dcbpy）Cl]Cl（H2L2）和[Ir-III（dcpy）（2）（H2O）（2）]OTf（H2L3）的MOF 1-3（其中Cp* 是五甲基吡啶，dcppy是2-苯基吡啶-5，4’-二羧酸，dcbpy是2，2’-联吡啶-5，5’-二羧酸）是有效的水氧化催化剂（WOC），周转频率（TOF）高达4.8 h（-1）。[Re-I（CO）（3）（dcbpy）Cl]（H2 L4）衍生的MOF 4作为光催化还原CO2的活性催化剂，总转化数（TON）为10.9，是均相配合物H2 L4的3倍. MOFs 5和6含有磷光[Ir-III（ppy）（2）（dcbpy）]Cl（H2 L5）和[Ru-II（bpy）（2）（dcbpy）]Cl-2（H2 L 6）（其中ppy是2-苯基吡啶，bpy是2，2 '-联吡啶），并用于三种具有非常高活性的光催化有机转化（aza-Henry反应、需氧胺偶联和需氧茴香硫醚氧化）。母体UiO-67骨架和反应上清液在催化水氧化、CO2还原和有机转化中的不活性表明了这些催化过程的分子起源和异质性。掺杂的UiO-67催化剂在催化条件下的稳定性也通过比较催化前后的PXRD图谱来证明。这项工作说明了分子催化剂和MOF结构相结合，在开发高活性的太阳能利用多相催化剂的潜力。
Catalytically competent Ir, Re, and Ru complexes H2L1-H2L6 with dicarboxylic acid functionalities were incorporated into a highly stable and porous Zr6O4(OH)(4)(bpdc)(6) (UiO-67, bpdc = para-biphenyldicarboxylic acid) framework using a mix-and-match synthetic strategy. The matching ligand lengths between bpdc and L-1-L-6 ligands allowed the construction of highly crystalline UiO-67 frameworks (metal-organic frameworks (MOFs) 1-6) that were doped with L-1-L-6 ligands. MOFs 1-6 were isostructural to the parent UiO-67 framework as shown by powder X-ray diffraction (PXRD) and exhibited high surface areas ranging from 1092 to 1497 m(2)/g. MOFs 1-6 were stable in air up to 400 degrees C and active catalysts in a range of reactions that are relevant to solar energy utilization. MOFs 1-3 containing [Cp*Ir-III(dcppy)Cl] (H2L1), [Cp*Ir-III(dcbpy)Cl]Cl (H2L2), and [Ir-III(dcppy)(2)(H2O)(2)]OTf (H2L3) (where Cp* is pentamethylcyclopentadienyl, dcppy is 2-phenylpyridine-5,4'-dicarboxylic acid, and dcbpy is 2,2'-bipyridine-5,5'-dicarboxylic acid) were effective water oxidation catalysts (WOCs), with turnover frequencies (TOFs) of up to 4.8 h(-1). The [Re-I(CO)(3)(dcbpy)Cl] (H2L4) derivatized MOF 4 served as an active catalyst for photocatalytic CO2 reduction with a total turnover number (TON) of 10.9, three times higher than that of the homogeneous complex H2L4. MOFs 5 and 6 contained phosphorescent [Ir-III(ppy)(2)(dcbpy)]Cl (H2L5) and [Ru-II(bpy)(2)(dcbpy)]Cl-2 (H2L6) (where ppy is 2-phenylpyridine and bpy is 2,2'-bipyridine) and were used in three photocatalytic organic transformations (aza-Henry reaction, aerobic amine coupling, and aerobic oxidation of thioanisole) with very high activities. The inactivity of the parent UiO-67 framework and the reaction supernatants in catalytic water oxidation, CO2 reduction, and organic transformations indicate both the molecular origin and heterogeneous nature of these catalytic processes. The stability of the doped UiO-67 catalysts under catalytic conditions was also demonstrated by comparing PXRD patterns before and after catalysis. This work illustrates the potential of combining molecular catalysts and MOF structures in developing highly active heterogeneous catalysts for solar energy utilization.