Zn Metal–Organic Framework with High Stability and Sorption Selectivity for CO2

By the employment of 5-amino-1H-tetrazole and pyromellitic acid ligands to assemble with Zn2+ ions, a three-dimensional3,4-connect fry network {[Zn2(HATZ)(ATZ)2(PMA)0.5]·(H2O)5}n (GUPT-1, HATZ = 5-amino-1H-tetrazole, H4PMA = pyromellitic acid) was isolated in the hydrothermal reaction, which features high stability and exhibits high adsorption selectivity of CO2/N2 (118) under ambient conditions and 1 bar. Moreover, grand canonical Monte Carlo (GCMC) simulation and the dispersion-corrected density functional theory (DFT-D) calculations reveal two types of binding sites: first, the electrostatic interactions between CO2 molecules and −NH2 groups exposed inside the channels and, second, the C···O interactions between the C atoms in the CO2 molecules and O atoms in the pyromellitic acid ligands. Furthermore, the static binding energy of CO2 molecules on GUPT-1 calculated by the DFT-D-simulated results was 38.49 kJ·mol–1, which corresponded to the experimental adsorption enthalpy (Qst) calculated to be 37.01 kJ·mol–1.