Synthesis of Hierarchically Structured Hybrid Materials by Controlled Self-Assembly of Metal Organic Framework with Mesoporous Silica for CO2 Adsorption
Synthesis of Hierarchically Structured Hybrid Materials by Controlled Self-Assembly of Metal Organic Framework with Mesoporous Silica for CO2 Adsorption
复制标题
金属有机骨架与介孔二氧化硅可控自组装合成多级结构杂化材料用于 CO2 吸附
DOI：
10.1021/acsami.7b08117
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发表时间：
2017-07-12
影响因子：
9.5
通讯作者：
Guan, Guofeng
中科院分区：
文献类型：
--
作者：
Chen, Chong;Li, Bingxue;Guan, Guofeng
通过金属有机骨架（MOF）与介孔SiO2的原位自组装，构建了具有分级孔结构的HKUST-1@SBA-15复合材料。SBA-15的结构导向作用对MOF晶体的生长有明显的影响，进而影响复合材料的形貌和结构性能。采用XRD、N2吸附-脱附、SEM、TEM、FT-1 R、TG、XPS和CO2-TPD等技术对HKUST-1和不同SBA-15含量的复合材料进行了表征。结果表明，复合材料是通过在SBA-15基体表面定向生长MOF纳米晶组装而成。杂化材料的表面硅醇基团与金属中心之间的相互作用导致了杂化材料的结构变化，并导致了杂化材料的比表面积和体积的增加。此外，SBA-15的附加约束也抑制了HKUST-1的膨胀，导致其在复合材料中的较小晶粒尺寸。测量了CO2在材料上的吸附等温线，并应用于计算等量吸附热。HS-1复合材料的CO2吸收能力比HKUST 1提高了15.9%。此外，其较高的CO2吸附等温热表明表面与CO2分子之间的相互作用较强。由于介孔的引入，复合材料的吸附速率也得到了提高。10个循环的CO2吸附-解吸实验表明，HS-1具有良好的CO2吸附可逆性。本研究的目的是提供组装新的复合材料的基础上的MOF和介孔二氧化硅的定制性能，以满足各种应用的要求的可能性。
The HKUST-1@SBA-15 composites with hierarchical pore structure were constructed by in situ self-assembly of metal organic framework (MOF) with mesoporous silica. The structure directing role of SBA-15 had an obvious impact on the growth of MOF crystals, which in turn affected the morphologies and structural properties of the composites. The pristine HKUST-1 and the composites with different content of SBA-15 were characterized by XRD, N-2 adsorption desorption, SEM, TEM, FT-1R, TG, XPS, and CO2-TPD techniques. It was found that the composites were assembled by oriented growth of MOF nanocrystals on the surfaces of SBA-15 matrix. The interactions between surface silanol groups and metal centers induced structural changes and resulted in the increases in surface areas as well as micropore volumes of hybrid materials. Besides, the additional constraints from SBA-15 also restrained the expansion of HKUST-1, contributing to their smaller crystal sizes, in the composites. The adsorption isotherms of CO2 on the materials were measured and applied to calculate the isosteric heats of adsorption. The HS-1 composite exhibited an increase of 15.9% in CO2 uptake capacity compared with that of HKUST1. Moreover, its higher isosteric heats of CO2 adsorption indicated the stronger interactions between the surfaces and CO2 molecules. The adsorption rate of the composite was also improved due to the introduction of mesopores. Ten cycles of CO2 adsorption desorption experiments implied that the HS-1 had excellent reversibility of CO2 adsorption. This study was intended to provide the possibility of assembling new composites with tailored properties based on MOF and mesoporous silica to satisfy the requirements of various applications.