A charged metal–organic framework for CO2/CH4 and CO2/N2 separation

A microporous metal–organic framework [InL][(CH3)2NH2]·(H4L = 9-(3,5-dicarboxyphenyl)carbazole-3,6-dicarboxylic acid) (1) was hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction and powder X-ray diffraction. The adsorption behavior of 1 has been investigated with respect to CO2, CH4 and N2, and the separation efficiency has been calculated by the Henry’s law analysis of isotherm data. The results indicated that the anionic framework with the inside protonated dimethylamine could enhance its selective adsorption performance for CO2 through strong adsorbent–adsorbate interaction aroused by a strong electrostatic field and pore size effect.