Gas sorption studies on a highly-thermostable microporous Zn(II) coordination polymer constructed from 2D honeycomb layers

Abstract

By combining experiment with molecular simulation, the CO2 sorption performance of a 2D honeycomb layered coordination polymer, {[Zn2(bpydb)2(H2O)2](DMA)3(H2O)}n (1) (bpydb=4,4′-(4,4′-bipyridine-2,6-diyl) dibenzoate) was systematically investigated. The desolvated 1 not only shows high CO2 capacity (72.5cm3/g at 273K and 42.9cm3/g at 298K) with a moderate high zero-coverage adsorption enthalpy (29.7kJ/mol), but also exhibits excellent CO2/N2 selectivity around room temperature. To better understand the adsorption behaviors and adsorption sites for CO2 in 1, GCMC simulations were carried out, which indicate that the open metal sites between two adjacent layers account for the high CO2 sorption capacity and strong CO2 binding ability. Moreover, the thermal stability of 1 was further confirmed by the TGA and VT-PXRD, which indicate that 1 could be thermally stable up to 400°C.