Immobilization of trigonal pyramidal copper(l) sites into  bibenzotriazole Metal‐Organic Framework for efficient one‐step methane purification

Abstract The production of high‐purity CH 4 (>99.99%) is critical for energy and advanced industrial applications, but the simultaneous removal of N 2 and O 2 remains a significant challenge. Herein, we report a Cu(I) coordination‐engineered metal–organic framework (Cu‐CFA‐1) based on theoretical design and experimental validation, which demonstrates remarkably selective adsorption of N 2 and O 2 over CH 4 , reversing the CH 4 selectivity of the parent material. In situ infrared spectroscopy and computational modeling studies revealed that the threefold coordination of Cu(I) by nitrogen ligands (Cu(I)‐3N) significantly enhances its electron‐donating capability, enabling targeted adsorption of π‐acidic gases (N 2 /O 2 ) through charge‐transfer effects. Breakthrough experiments demonstrated that Cu‐CFA‐1 can provide high‐purity CH 4 in a single adsorption–desorption cycle from ternary (N 2 /O 2 /CH 4 ) and even six‐component (N 2 /O 2 /CH 4 /CO 2 /C 2 H 6 /C 3 H 8 ) gas mixtures. This work provides an energy‐efficient solution for CH 4 purification from multicomponent systems, and establishes a theoretical and practical foundation for the mechanism of π‐acidic gas adsorption.