Co3(HCOO)6 microporous metal-organic framework membrane for separation of CO2/CH4 mixtures.
Co3(HCOO)6 microporous metal-organic framework membrane for separation of CO2/CH4 mixtures.
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DOI：
10.1002/chem.201101733
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
Xiaoqin Zou;Feng Zhang;Sébastien Thomas;G. Zhu;V. Valtchev;S. Mintova
中科院分区：
文献类型：
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作者：
Xiaoqin Zou;Feng Zhang;Sébastien Thomas;G. Zhu;V. Valtchev;S. Mintova
采用二次生长法在大孔玻璃粉片和硅片上制备了具有一维锯齿形孔道结构的Co（3）（HCOO）（6）金属-有机骨架共生长薄膜。用原位红外光谱研究了CO（2）和CH（4）单一气体在Co（3）（HCOO）（6）膜上的吸附行为。结果表明，CO（2）和CH（4）的等排吸附热不随吸附量的增加而变化，分别为17.7kJmol（-1）和14.4kJmol（-1）。CO（2）的等排热的较高值表明CO（2）和Co（3）（HCOO）（6）膜之间的相互作用较强。通过在不同温度（0、25和60 °C）下CO（2）和CH（4）的二元气体渗透来研究Co（3）（HCOO）（6）膜。该膜具有CO（2）/CH（4）的选择性，分离因子大于10，这是由于其独特的结构和分子筛效应。当温度从0升高到60 °C时，CO（2）相对于CH（4）的优选渗透率从1.70×10（-6）增加到2.09×10（-6）mol m（-2）s（-1）Pa（-1），而CO（2）/CH（4）的分离因子显示出相应的从15.95降低到10.37。Co（3）（HCOO）（6）材料的有效孔径与孔形状相结合不允许两种分子同时通过，一旦CO（2）分子在微孔中扩散，CH（4）就被阻挡。负载的Co（3）（HCOO）（6）膜在多次热循环后保持高的机械稳定性。
Continuous metal-organic framework-type Co(3)(HCOO)(6) intergrown films with a one-dimensional zigzag channel system and pore aperture of 5.5 Å are prepared by secondary growth on preseeded macroporous glass-frit disks and silicon wafers. The adsorption behavior of CO(2) or CH(4) single gases on the Co(3)(HCOO)(6) membrane is investigated by in situ IR spectroscopy. It is shown that the isosteric heats of adsorption for CO(2) (17.7 kJ mol(-1)) and CH(4) (14.4 kJ mol(-1)) do not vary with increasing amount of adsorbed gases. The higher value of isosteric heat for CO(2) is an indication of the stronger interaction between the CO(2) and the Co(3)(HCOO)(6) membrane. The Co(3)(HCOO)(6) membrane is studied by binary gas permeation of CO(2) and CH(4) at different temperatures (0, 25, and 60 °C). The membrane has CO(2)/CH(4) selectivity with a separation factor higher than 10, which is due to the unique structure and molecular sieving effect. Upon increasing the temperature from 0 to 60 °C, the preferred permeance of CO(2) over CH(4) is increased from 1.70×10(-6) to 2.09×10(-6) mol m(-2) s(-1) Pa(-1), while the separation factor for CO(2)/CH(4) shows a corresponding decrease from 15.95 to 10.37. The effective pore size of the Co(3)(HCOO)(6) material combined with the pore shape do not allow the two molecules to pass simultaneously, and once the CO(2) molecules are diffused in the micropores, the CH(4) is blocked. The supported Co(3)(HCOO)(6) membrane retains high mechanical stability after a number of thermal cycles.