Extremely Stable Sulfuric Acid Covalent Organic Framework for Highly Effective Ammonia Capture†

Comprehensive Summary Ammonia (NH 3 ) is one of the most important industrial feedstocks in the fields of fertilizers, drugs, explosives, ordnance, commercial cleanings, and so on. However, the features of ammonia such as high toxicity and corrosivity, and difficulty in handling would inevitably increase the risk of environmental damage and the deterioration of natural/public lands. Although sorts of solid adsorbents such as metal oxides, zeolites, organic polymers, activated carbons, and metal organic frameworks have been applied in NH 3 capture, they still show low uptake capacity, low affinities, and instability. Herein, we developed the first case of a highly stable sulfuric acid covalent organic framework (COF), namely TpBD‐(SO 3 H) 2 , as NH 3 capturer, in which sulfonic acid sites can strongly interact with NH 3 molecules, and enhance the performance of NH 3 sorption. As a result, TpBD‐(SO 3 H) 2 shows high chemical stability under strong acid and water conditions, an important merit for the potential application in harsh environment. And it also exhibits high ammonia capacity of 11.5 mmol·g −1 at 298 K and 1.0 bar, making it one of the best in all chemically stable NH 3 adsorbents up to date. This work thus develops sulfuric acid COF materials as a new platform for ammonia capture and storage.