A Metal‐Organic Framework with Tailored Shape‐Matched Interactions Towards Ambient‐Temperature Argon Removal for Oxygen Purification

High‐purity oxygen (O 2 ) is essential for high‐value‐added applications in the medical, aerospace, and electronics sectors. The production of high‐purity O 2 via non‐thermal‐driven pressure‐swing adsorption has the advantages of portable operation and low energy consumption. However, effectively removing trace amounts of argon (Ar) impurities in this process is indispensable, and it is a fundamental challenge to achieve the preferential adsorption of inert Ar atoms over polar O 2 molecules instead of traditional thermodynamic or molecule sieving strategies. Herein, we have demonstrated this problem was addressed by integrating spheroidal shape‐matched interactions to fit the spheroid Ar atoms while repulsing the linear O 2 molecules. Using this strategy, customized TYUT‐20 enables the exceptional recognition of Ar atoms over O 2 molecules, demonstrating an unprecedented Ar adsorption capacity of up to 14.5 cm 3 g −1 and a top‐performing Ar/O 2 (1.54) selectivity at 298 K and 1 bar. The Ar atom recognition mechanism on this adsorbent has been investigated using Ar‐loaded single crystal diffraction analysis and molecular simulation studies. The productivity of high‐purity O 2 (>99.99%) from a 5/95 Ar/O 2 mixture breakthrough experiment reached 6.6 L kg −1 under ambient conditions, which highlighted TYUT‐20 as a very promising adsorbent in ready‐to‐use high‐purity O 2 production.