Cu-MOFs with Rich Open Metal and F Sites for Separation of C2H2 from CO2 and CH4.

Herein, we used the 4-fluoro-[1,1'-biphenyl]-3,4',5-tricarboxylic acid (H3fbptc) ligand to design and construct a new metal-organic framework (MOF), [Cu3(fbptc)2(H2O)3]·3NMP (1), which possesses rich accessible metal sites and F functional groups in the porous walls and shows high uptake for C2H2 (119.3 cm3 g-1) and significant adsorption selectivity for C2H2 over CH4 (14.4) and CO2 (3.6) at 298 K and 100 kPa. In particular, for the gas mixtures of C2H2-CH4 and C2H2-CO2, the MOF reveals large breakthrough time ratios (C2H2/CH4 = 13, C2H2/CO2 = 5.9), which are particularly prominent in dynamic breakthrough experiments, also confirming the excellent potential for the practical separation of C2H2 from two-component mixtures (C2H2-CH4 and C2H2-CO2) and even three-component mixtures (C2H2-CO2-CH4).

A new metal-organic framework based on rare [Zn4F4] cores for efficient separation of C2H2.

Assembly via 1,4-benzenedicarboxylate linkers and Zn2+ ions afforded an MOF containing rare [Zn4F4] cubane core, showing excellent separation for C2H2-CO2 and C2H2-CH4 mixtures. Dynamic breakthrough experiments and grand canonical Monte Carlo calculations were carried out to confirm the feasibility of the MOF for the separation application of C2H2.