A Cationic Polymerization Strategy to Design Sulfonated Micro–Mesoporous Polymers as Efficient Adsorbents for Ammonia Capture and Separation

Abstract

Ammonia (NH3) is a corrosive, harmful, but very important chemical, and selective capture and separation of NH3 are crucial for its safe utilization. Herein, we designed a class of micro–mesoporous organic polymers functionalized with a sulfonic group (MPOP-x-SO3H) by a fast, template-free cationic polymerization of divinylbenzene (DVB) at ambient temperature, and H2SO4 as both the initiator and sulfonation agent was introduced. The resultant MPOP-x-SO3H possesses large BET surface areas (275–630 m2/g), abundant micro–mesoporosity, superior hydrophobicity, and enhanced acidity with tunable contents (0.32–1.67 mmol/g). As a result, MPOP-x-SO3H can reversibly capture and separate low-concentrated NH3 from a N2/H2/NH3 mixed gas, and its performances are superior to many reported NH3 adsorbents, which finds applications in removing leaked or undesired NH3 in industrial processes. Micro–mesoporous polymers decorated with other functional groups (pyridine, imidazole, and metal nanoclusters) could also be designed by the template-free cationic polymerization strategy.