Anchoring LiCl in the Nanopores of Metal–Organic Frameworks for Ultra‐High Uptake and Selective Separation of Ammonia

Ammonia (NH₃ ) is an important chemical raw material and a unique carbon-free fuel with high hydrogen energy density. Thus, NH₃ capture, storage, and desorption are of significant importance. However, high capacity capture, low energy desorption, and selective separation of NH₃ are still challengs so far. Here, we report high-performance hybrid sorbents by anchoring LiCl in the nanopores of MIL-53-(OH)₂ metal-organic frameworks (MOFs). It is found that the optimal composite shows a capture capacity of 33.9 mmol g^-1 NH₃ at 1.0 bar and 25 °C, which far exceeds the current record among the reported porous materials. Notably, the excellent capture capacity at low pressure and high temperature makes it possible to selectively capture NH₃ from NH₃ /N₂ , NH₃ /CO₂ , and NH₃ /H₂ O. It is revealed that synergistic action of NH₃ coordination to the highly dispersed Li⁺ in the MOF nanopores and hydrogen bonding of NH₃ with Cl^- account for such an excellent capture and selectivity performance.