The amine-functionalized metal-organic frameworks are regarded as promising adsorbents for capturing CO2 from coal-firedflue gas due to their high porosity,large CO2 adsorption capacity,and good water resistance. However,the aggregation of surface aminemolecules during high-temperature desorption processes leads to a drop in both adsorption rate and uptake. In this study,a novel amine-functionalized adsorbent was developed by physically encapsulating tetraethylenepentamine molecules into the pores of MOF-808(TEPA@MOF-808) through a simple impregnation method. Compared to pristine MOF-808,TEPA@MOF-808 exhibited a 2.15-foldincrease in CO2 adsorption uptake,along with enhancements of 13% in adsorption rate constant and 498% in adsorption selectivity. After10 cycles, its adsorption uptake only decreased by 10.9%. Thermodynamic analysis revealed a low heat of adsorption of 40 kJ/mol,suggesting a physical adsorption mechanism. C SSNMR and in situ DRIFTS characterization further elucidated the CO2 physisorptionmechanism of TEPA@MOF-808.

沈遥(1994—),男,浙江德清人,助理研究员,博士。E-mail:yaoshen@zjut.edu.cn

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SHEN Yao,LU Hengxia,PAN Xingdi,et al. Development and mechanism of amine-functionalized MOF-808 for efficient and stable CO2 adsorption[J].Clean Coal Technology,2024,30(10):78−88.