文摘
Ab initio calculations and GCMC simulations were performed in order to study the CO2 adsorption from Mg modified IRMOF-10. The Mg cations were introduced in the linker of IRMOF-10 by creating Mg alkoxide groups. Accurate MP2 calculations on the Mg alkoxide linker showed that up to 4 CO2 molecules can simultaneously interact with the Mg atom of the alkoxide group. The average interaction energy ranged from 鈭?4.2 to 鈭?.9 kcal路mol鈥? for one to four interacting CO2. GCMC simulations were also employed using a modified LJ potential in order to predict the excess CO2 adsorption isotherms at 300 K and up to 40 bar. The predicted isotherms showed a clear enhancement of the CO2 uptake when one or two Mg alkoxide groups were introduced per linker with respect to the unmodified IRMOF-10. This enhancement was more pronounced at low pressures. At 10 bar, the volumetric capacity became 5 or 7 times larger than in the case of the unmodified IRMOF-10 by introducing 1 or 2 Mg alkoxide groups, respectively. Based on this significant enhancement, we propose the Mg functionalization as a general strategy for improving the CO2 storage capacity in MOFs and similar materials.