Highly Dispersed Ionic Liquids in Mesoporous Molecular Sieves Enable a Record NH<sub>3</sub> Absorption
Doudou Cao, Zhiyong Li, Zhenzhen Wang, Huiyong Wang, Shuaiqi Gao, Yu Wang, Yunlei Shi, Jikuan Qiu, Yang Zhao, Jianji Wang
Abstract
Ammonia (NH3) has high hydrogen energy density and is a promising sustainable energy in the future. However, developing simple, stable, and efficient materials for NH3 uptake and storage remains a challenge. Here, a family of stable ionic liquid hybrid materials has been developed by a simple impregnation of Zn-based ionic liquids (ZnILs) into a stable mesoporous molecular sieve FDU-12 for high-efficient NH3 capture. The ZnIL hybrid adsorbents exhibit a record NH3 adsorption capacity (25.2 mmol/g at 25.0 °C and 1.0 bar), along with an exceptionally high uptake at high temperature (15.2 mmol/g at 80.0 °C and 1.0 bar) and low NH3 concentration (5.0 mmol/g at 25.0 °C and 10,000 ppm). Notably, [C1NH3][Zn3Cl7]@FDU-12-40% shows an almost unchanged breakthrough performance after five cycles, indicating excellent cycling stability of these hybrid adsorbents. It is revealed that such superior NH3 capacity is mainly attributed to the highly dispersed ZnILs in FDU-12, which facilitate the coordination and hydrogen-bonding interactions of NH3 with the ILs.