An Ultramicroporous Metal‐Organic Framework With Ultrahigh Neon Adsorption Capacity and Record Ne/He Selectivity

The removal of trace neon from helium represents a critical bottleneck in the production of ultrahigh‐purity helium, which is indispensable for advanced technologies such as semiconductor manufacturing and cryogenics. Existing adsorbents suffer from either low selectivity or insufficient capacity under practically viable cryogenic conditions, often necessitating energy‐intensive processes below 50 K. Herein, we report an ultramicroporous metal–organic framework, UTSA‐280, that enables highly efficient Ne/He separation at the industrially accessible temperature of liquid nitrogen (77 K). UTSA‐280 features rigid 1D channels with tailored aperture sizes (3.2 × 4.5 and 3.8 × 3.8 Å 2 ) and a polarized electrostatic environment arising from Ca 2+ centers and squaric acid ligands, which can achieve a record Ne/He selectivity of 1602 and an exceptional Ne uptake of 5.419 mmol·g −1 at 77 K and 100 kPa. Breakthrough experiments and process simulations confirm its ability to produce high‐purity helium directly from a Ne/He (0.1/99.9) mixture, providing an energy‐efficient and scalable strategy to address the growing demand for ultra‐pure helium in electronic and cryogenic applications.