Zn Metal-Organic Framework with High Stability and SorptionSelectivity for CO2

By the employment of 5-amino-1H-tetrazole and pyromellitic acidligands to assemble with Zn2+ions, a three-dimensional3,4-connectfrynetwork{[Zn2(HATZ)(ATZ)2(PMA)0.5]middot(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 MonteCarlo (GCMC) simulation and the dispersion-corrected density functional theory(DFT-D) calculations reveal two types of binding sites:first, the electrostaticinteractions between CO2molecules and-NH2groups exposed inside thechannels and, second, the CmiddotmiddotmiddotO interactions between the C atoms in the CO2molecules and O atoms in the pyromellitic acid ligands. Furthermore, the staticbinding energy of CO2molecules onGUPT-1calculated by the DFT-D-simulatedresults was 38.49 kJmiddotmol-1, which corresponded to the experimental adsorptionenthalpy (Qst) calculated to be 37.01 kJmiddotmol(-1)

Automated summary

In this study, a three-dimensional network with high stability and high adsorption selectivity was synthesized by employing 5-amino-1H-tetrazole and pyromellitic acid ligands to assemble with Zn2+ ions. The study revealed two types of binding sites for CO2 molecules in the network.