5.
A novel metal-doped metal–organic framework (MOF) was developed by incorporating salen–Mg into NH
2–MIL-101(Cr) structure under ambient conditions. The Schiff base complex was successfully prepared by condensing salicylaldehyde with a free amino group and then coordinating metal ions. Such a structure can endow the sample with higher CO
2 adsorption performance. At 0°C and 1 bar, the salen–Mg-modified sample achieves the maximum adsorption capacity of 2.18 mmol g
−1 for CO
2, which was 5.8% higher than the pristine salen–MOF under the same conditions. Notably, the Freundlich model indicates that the CO
2 adsorption process of all samples conforms to reversible adsorption. However, the correlation coefficients (
R2) of the Mg-doped sample are lower than that of the pristine sample. Besides, the CO
2/N
2 adsorption selectivity and isosteric heat also show a similar trend. These results indicate that the salen–Mg can enhance the interaction between the material and CO
2 molecules.
相似文献