Amino-Functionalized Water-Stable Metal-Organic Framework for Enhanced C2H2/CH4 Separation Performance

Using a hydrothermal method, a water-stable metal-organic framework based on 8-connected Ni-2 units with (4.6(2) )2(4(7).6(13).8(3)) topology, [Ni-2(mu(2)-OH2)(ctpd)(2) (NH2-bdc)]center dot(EtOH)(2)center dot(H2O)(2) (NbU-9-NH2), constructed by mixing a rigid tridentate ligand and an amino-p-carboxyl ligand, displays an enhanced ability for adsorbing C2H2 and adsorptive selectivity for C2H2/CH4. Dispersion-corrected density functional theory calculation confirmed that the enhenced acetylene adsorption is mainly derived from the weak hydrogen-bonding between a hydrogen atom of C2H2 and the nitrogen atom of the amino group.