Humidity swing adsorption of H2S by fibrous polymeric ionic liquids (PILs).

Graphical abstract Highlights • A novel H 2 S sorbent, fibrous polymeric ionic liquids, was proposed. • The sorbent showed large adsorption capacity and outstanding adsorption kinetics. • An economical water-promoting regeneration method was proposed. • Atom-level study revealed the underlying mechanisms of humidity swing adsorption. • The sorbent presented promising regenerability and cycle stability. Abstract A novel H 2 S adsorbent, fibrous polymeric ionic liquids (PILs), was proposed in this study, for they combine the advantages of ionic liquids and characteristics of macromolecular architecture. After modified with basic anion, the sorbent showed excellent performance for low concentration of H 2 S adsorption under room temperature. The fixed bed breakthrough experiment showed that the adsorption capacity is up to 1.75 mmol/g and the adsorption kinetics is comparable to that of mental oxide at 300 °C. Despite the strong affinity for H 2 S, the saturated sorbent could be regenerated under wet conditions, which inspires an economical water-promoting regeneration method. Further investigations through density functional theory (DFT) calculations revealed that the interface water would alter the reaction pathways of H 2 S adsorption and lower the activation energy of desorption reaction, which makes H 2 S desorption faster. After eight adsorption-desorption cycles, the sorbent did not show any detectable loss of H 2 S adsorption capacity. Therefore, the results of this study indicate that the fibrous PILs are promising regenerable sorbent for low concentration H 2 S removal at room temperature. [ABSTRACT FROM AUTHOR]