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 Ni2 units with (4·62)2(47·613·83) topology, [Ni2(μ2-OH2)(ctpd)2(NH2-bdc)]·(EtOH)2·(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.