Ionic liquid hybrid metal–organic frameworks for efficient adsorption and selective separation of ammonia at high temperature

Efficient adsorption and selective separation of ammonia at high temperature is a crucial and challenging issue. In this work, a series of stable ionic liquid hybrid materials have been developed by simple impregnation of ionic liquids into stable metal–organic framework Al-fum with 1D pores. The hybrid material [C 2 N][Zn 3 Cl 7 ]@Al-fum-60% exhibited an exceptionally high uptake (9.9 mmol/g at 80 °C, 8.8 mmol/g at 100 °C) at high temperature, excellent uptake (9.8 mmol/g at 25.0 °C) at low ammonia concentration (100,000 ppm), and remarkable selective separation performance (selectivity factor is 25.1) of NH 3 from NH 3 /CO 2 mixture at high temperature. The NH 3 uptake of [C 2 N][Zn 3 Cl 7 ]@Al-fum-60% at 100 °C was higher than the capacity of most of typical porous NH 3 adsorbents at room temperature. It is revealed that such superior NH 3 capacity and selective separation performance are mainly attributed to coordination interactions of NH 3 to Zn centre of the ionic liquids and the hydrogen bonding interactions of NH 3 with Cl of the ionic liquids and NH 3 with μ-OH of Al-fum.