Mesoporous polymer supported Metal-Based deep eutectic solvents for enhanced capture of Low-Content Ammonia

[Display omitted] •Series of metal-based DESs containing ChCl and metal chlorides were prepared.•The metal-based DESs were dispersed in mesoporous PDVB for NH3 capture.•The DES@PDVB composites exhibit considerably high NH3 capacities at low contents.•The NH3 capacities of DES@PDVB composites are higher than most other adsorbents.•Coordination and hydrogen-bond interaction contributes to the enhanced capture of NH3. The capture the low-content NH3 from industrial streams, and recycle it as the feedstocks for industrial processes is very important. In this work, we reported the use of mesoporous polydivinylbenzene (PDVB) as the support of metal-based deep eutectic solvents (DESs) containing choline chloride (ChCl) and metal chlorides (SnCl2, FeCl3 or ZnCl2) for NH3 capture. The structure of composite materials was characterized in details, and the NH3 capture performance and mechanism of them were also examined in depth. Owing to the coordination interaction of metal ions with NH3, along with the hydrogen-bond interaction of − OH and Cl− with NH3, the DES@PDVB composites exhibit considerably high low-content NH3 capacities. The optimized sample ChCl + 2ZnCl2@PDVB-1.5 can adsorb 7.43 mol/kg of NH3 at 25 ℃ and 0.122 bar, which is advantageous over most other adsorbents fabricated in the literature. The mechanism of NH3 capture by DES@PDVB composites was also illustrated through spectroscopic characterizations.