Fabricating a Robust Ultramicroporous Metal‐Organic Framework for Purifying Natural Gas and Coal Mine Methane

Abstract Purifying methane (CH 4 ) from natural gas and coal mine methane (CMM) is of great significance but challenging in the chemical industry. Herein, a robust ultramicroporous metal‐organic framework (MOF) is reported, which can be synthesized on a gram scale by stirring under room temperature. Single‐component adsorption isotherms of gases (CH 4 , ethane (C 2 H 6 ), propane (C 3 H 8 ), nitrogen (N 2 )) and breakthrough experiments indicate that the MOF can separate CH 4 efficiently from CH 4 /C 2 H 6 /C 3 H 8 ternary mixture, with super high purity‐CH 4 production of 154.7 cm 3 g −1 . Additionally, the MOF shows higher CH 4 capacity than N 2 , resulting in excellent separation performance for the CH 4 /N 2 mixture. Notably, the binding sites of gases can be precisely determined by single‐crystal X‐ray data, further confirmed by molecular simulation. It is found that there are multiple hydrogen bonds and C─H···π interactions between the gases and the framework. This work offers an excellent candidate material for CH 4 purification with both high capacity and separation efficiency.