金属有机框架材料HKUST-1吸附分离CH4/N2性能研究

以均苯三甲酸为配体，与金属离子Cu2+自组装得到稳定的金属有机框架材料（HKUST-1），并借助N2吸附-脱附、X射线粉末衍射、热重、SEM等对其结构进行表征，利用气体吸附仪测量了CH4和N2的吸附等温线，采用克-克（Clausius-Clapeyron）方程计算CH4的吸附热，并运用理想吸附溶液理论（ IAST）来计算HKUST-1对CH4/N2的分离因子。结果表明：在0℃、101.325 kPa和25℃、101.325 kPa的条件下，HKUST-1的CH4吸附量分别为25.1 cm3/g和15.2 cm3/g，N2吸附量分别为8.0 cm3/g和3.9 cm3/g，所制备的HKUST-1对CH4具有较好的吸附效果； HKUST-1对CH4/N2的选择性分离因子为6.8，对CH4/N2具有很好的分离效果； HKUST-1对CH4的吸附热为20 kJ/mol左右，与分子筛类吸附剂相比吸附热较小，易于再生。

ADSORPTION SEPARATION OF CH4/N2 OVER METAL ORGANIC FRAME MATERIAL HKUST-1

The HKUST-1 was obtained using trimesic acid self-assembly with Cu2+ and characterized by N2 adsorption，X-ray powder diffraction，TGA and SEM. Adsorption values of CH4 and N2 were measured by gas adsorption instrument. The Clausius-Clapeyron equation was used to calculate the adsorption heat of CH4. The separation coefficient of CH4/N2（SCH4/N2）was calculated by Ideal Adsorbed Solution Theory（IAST）. The results showed that HKUST-1 has a good adsorption effect on CH4. At conditions of 0 ℃，101.325 kPa and 25 ℃，101.325 kPa，the adsorption values of CH4 are 25.1 cm3/g and 15.2 cm3/g，the adsorption values of N2 are 8.0 cm3/g and 3.9 cm3/g，respectively. The selectivity factor for CH4 /N2 is 6.8，and the isosteric heat of adsorption of CH4 is about 20 kJ/mol. Compared with zeolite-like adsorbents，the isosteric heat was smaller，which meant a facile regeneration of adsorbents.