Incorporation of Lewis basic sites into Zn‐pyrazolate frameworks for efficient methane/nitrogen separation

Abstract The separation of methane (CH 4 ) and nitrogen (N 2 ) in coalbed methane (CBM) is a crucial process to produce methane as a clean energy source. Given the similar physicochemical properties of the two gases, efficient adsorptive separation of CH 4 and N 2 has stringent requirements on the pore chemistry and geometry of the adsorbents. In this study, we report two Zn‐pyrazolates frameworks, HIAM‐213 and HIAM‐214, which possess Lewis basic sites that exhibit precise recognition of CH 4 over N 2 . The capability of these compounds in extracting CH 4 from binary CH 4 /N 2 mixtures has been confirmed through column breakthrough measurements, demonstrating a high recovery rate under mild regeneration conditions. Grand canonical Monte Carlo simulations and in situ Fourier transform infrared spectroscopy experiments provide insights into the selective adsorption mechanism by revealing stronger interactions between CH 4 and Lewis acid sites.