Bimetallic Metal-Organic Frameworks: Probing the Lewis Acid Site for CO2 Conversion
Bimetallic Metal-Organic Frameworks: Probing the Lewis Acid Site for CO2 Conversion
复制标题
双金属金属有机框架：探测二氧化碳转化的路易斯酸位点
DOI：
10.1002/smll.201503741
复制
发表时间：
2016
期刊：
影响因子：
13.3
通讯作者：
Zhao Yanli
中科院分区：
文献类型：
--
作者：
Zou Ruyi;Li Pei-Zhou;Zeng Yong-Fei;Liu Jia;Zhao Ruo;Duan Hui;Luo Zhong;Wang Jin-Gui;Zou Ruqiang;Zhao Yanli
一种高度多孔的金属有机框架（MOF），其包含两种第二结构单元（SBU），即，通过三羧酸配体与ZnIII离子的反应，成功地组装了二聚体桨轮（Zn 2（COO）4）和四聚体（Zn 4（O）（CO 2）6）。随后，使用构建的MOF研究单晶到单晶的金属阳离子交换，结果表明，Cu II和Co II离子可以选择性地引入到MOF中，而不损害原始框架的结晶度。这种金属阳离子可交换的MOF为研究金属对所得MOF的气体吸附和催化活性的影响提供了有用的平台。虽然气体吸附实验表明，Cu II和Co II交换的样品在相同条件下表现出与原始Zn II-基MOF相当的CO2吸附能力，但对CO2与环氧化物环加成反应成相关碳酸酯的催化研究表明，与Cu II和Co II交换的样品相比，Zn II-基MOF提供了最高的催化活性。分子动力学模拟进一步证实了这些构建的MOFs对CO2化学固定到碳酸盐的催化性能。这项研究揭示了金属交换如何影响MOFs的内在性质。
A highly porous metal‐organic framework (MOF) incorporating two kinds of second building units (SBUs), i.e., dimeric paddlewheel (Zn2(COO)4) and tetrameric (Zn4(O)(CO2)6), is successfully assembled by the reaction of a tricarboxylate ligand with ZnIIion. Subsequently, single‐crystal‐to‐single‐crystal metal cation exchange using the constructed MOF is investigated, and the results show that CuIIand CoIIions can selectively be introduced into the MOF without compromising the crystallinity of the pristine framework. This metal cation‐exchangeable MOF provides a useful platform for studying the metal effect on both gas adsorption and catalytic activity of the resulted MOFs. While the gas adsorption experiments reveal that CuIIand CoIIexchanged samples exhibit comparable CO2adsorption capability to the pristine ZnII‐based MOF under the same conditions, catalytic investigations for the cycloaddition reaction of CO2with epoxides into related carbonates demonstrate that ZnII‐based MOF affords the highest catalytic activity as compared with CuIIand CoIIexchanged ones. Molecular dynamic simulations are carried out to further confirm the catalytic performance of these constructed MOFs on chemical fixation of CO2to carbonates. This research sheds light on how metal exchange can influence intrinsic properties of MOFs.