Priority recognition separation of inert and larger ethane molecules from high‐concentration ethylene mixtures instead of traditional thermodynamic or size sieving strategy is a fundamental challenge. Herein, we report the ethane triggered gate‐opening in the flexible‐robust metal−organic framework Zn(ad)(min), the 3‐methylisonicotinic acid ligand can spin as a flexible gate when adsorbing the cross‐section well‐matched ethane molecule, thus achieving the unprecedent ethane adsorption capacity (62.6 cm3 g‐1) and ethane/ethylene uptake ratio (3.34) under low‐pressure region (0.1 bar and 298 K). The ethane‐induced structural transition behavior is uncovered by a collaboration of single‐crystal X‐ray diffraction, in‐situ variable pressure X‐ray diffraction and theoretical calculations, elucidating the synergetic mechanism of cross‐section matching and multiple supramolecular interactions within the tailor‐made pore channels. Dynamic breakthrough experiments revealed the outstanding separation performance of Zn(ad)(min) in the production of ultra‐high purity ethylene (&gt; 99.995%) with a productivity of up to 39.2 L/kg under ambient conditions.

Ethane Triggered Gate‐Opening in a Flexible−Robust Metal−Organic Framework for Ultra‐high Purity Ethylene Purification