Optimized Nanospace Of Coordination Isomers With Selenium Sites For Acetylene Separation

The safe storage and separation of acetylene (C2H2) is difficult and essential, due to its explosive properties and wide usage for various industrial products. With a generally low energy cost, highly efficient adsorption separation has been considered as a promising solution. Taking advantage of the inbuilt nature of a tunable pore space, a porous coordination polymer (NTU-56) was prepared from a selenium-containing carboxylate ligand and Cu(2+)ions. Triggered by water at different temperatures,NTU-56transformed into two other porous frameworks (NTU-57andNTU-58) with different topologies and pore environments. Single-component gas adsorption experiments showed that this new group of porous isomers featured systematically varied adsorption selectivity for C2H2/CO2, two gases that have extremely similar molecular sizes and boiling points. More interestingly, among the isomers,NTU-58, a rare 2D, flexible, and water-stable framework, has the highest C(2)H(2)uptake (60 cm(3)g(-1)) and C2H2/CO(2)selectivity (13.9, 1/1, v/v, 1 bar) at 273 K, derived from the synergetic effect of the unique pore sizes (4.5 and 5.5 angstrom) and pore surface polarity, where the Cu(2+)and selenium sites are exposed for preferred C(2)H(2)interactions. Efficient and recyclable C2H2/CO(2)separation was also confirmedviabreakthrough experiments, even with wet feed-gas.