Enhanced stability and hydrophobicity of LiX@ZIF-8 composite synthesized environmental friendly for CO2 capture in highly humid flue gas

Decreased adsorption capacity and complicated synthetic procedures with expensive or toxic raw chemicals are two major challenges faced by physical adsorbents for carbon capture in highly humid flue gas. In this study, a novel core-shell composite using LiX with high CO2 adsorption capacity as core and superior hydrophobic ZIF-8 as shell is proposed. The overall synthesis process is conducted under ambient temperature and pressure by adopting deionized water as green solvent. Experimental results show that the adsorption performance of the core-shell structure is enhanced along with the improvement of hydrophobic performance in highly humid flue gas. The performance of ZIF-8 shells from monolayer to multilayers (up to three layers) are investigated. In particular, [email protected] with single layer of ZIF-8 exhibit the highest CO2 adsorption capacity of 1.73 mmol/g in humid flue gas. The monolayered adsorbent not only exhibit superior hydrophobicity and CO2 adsorption capacity but also maintain excellent hydrothermal stability in humid flue gas over 50 adsorption/desorption cycles, which promote its application to practical in a green, energy-saving and economical way.