Zr-Based Metal–Organic Framework with Wall-Shared Dual Ultramicroporous Channels for Effective CH₄/N₂ Separation

The adsorptive separation of methane (CH4) and nitrogen (N2) is a challenging yet crucial process in the purification of unconventional natural gas. In this work, we report a robust Zr-based metal–organic framework, termed as MIP-203-F, for the selective adsorption of CH4 from CH4/N2 mixtures with varied concentrations. The framework possesses a rhombic one-dimensional (1D) micropore structure that is effectively divided into two symmetric wall-shared triangular pores by the presence of pendent −OH groups, which endow the material with an optimal pore size and a plethora of synergistic polar sites, facilitating the efficient adsorption of CH4 with a high polarizability and overcoming the trade-off between CH4 capacity and CH4/N2 selectivity. The exceptional separation performance of MIP-203-F was validated through comprehensive experimental investigations encompassing thermodynamic analyses, breakthrough experiments, and theoretical calculations. These findings underscore the immense potential of MIP-203-F as a promising candidate for the adsorptive separation of CH4/N2.