Carbon Dioxide Adsorption over Amine-Functionalized MOFs

摘要

This paper focused on the CO2 absorption process of UiO-66/PEI composites by using experimental and computational methods. UiO-66 was synthesized by hydrothermal method and further modified with Polyethylenimine (PEI) molecules. The synthetic samples were characterized through X-ray diffraction, infrared IR, and nitrogen adsorption-desorption. The effect of PEI loading and adsorption temperature on CO2 adsorption are investigated. The results indicate that the CO2 adsroptioncapacity of UiO-66/PEI at 25 °C were up to 3.13 mmol/g, which is 1.5 times greater than that of the parent UiO-66. On the basis of the validated experimental result, the Grand Canninical Monte Carlo (GCMC) molecular simulation method was used to calculate the probability density distribution of the CO2 adsorption in the skeleton, adsorption position, adsorption energy distribution as . well as diffusion characteristics. The simulated results discover that the amine-group play a key role to increase adsorption capacity of compound MOFs, and these excellent properties make it a type of promising adsorbents in CO2 storage and separation.