Cyclodextrin-assisted high selectivity of imprinted adsorbents loaded on polyoxometalate@UiO-66 for H2S removal at ambient temperature

The efficient removal of H 2 S is necessary for clean production and energy safety. However, industrial gases are usually accompanied by CO 2 significantly affecting desulfurization effects. Hence, novel imprinted adsorbents (PMo 12 @UiO-66@H 2 S-MIP-CDs) were synthesized through surface imprinting technology using cyclodextrins (CDs) as molecular scaffolds and UiO-66 modified by phosphomolybdic acid (PMo 12 @UiO-66) as a support. Wherein, PMo 12 @UiO-66@H 2 S-MIP-β-CD was determined as the optimal adsorbent since β-CD with low solubility is prone to keep its inherent cavity to promote dispersion of imprinted polymers and enrich internal pore channels. H 2 S capacity of PMo 12 @UiO-66@H 2 S-MIP-β-CD (31.67 mg/g) was about 2.4 and 1.7 times that of PMo 12 @UiO-66 and PMo 12 @UiO-66@H 2 S-MIPs, respectively, revealing the remarkable contribution of β-CD as a molecular scaffold to improve desulfurization. The results showed that PMo 12 @UiO-66@H 2 S-MIP-β-CD can maintain stable desulfurization efficiency regardless of the presence of CO 2 or moisture, and O 2 can strengthen the redox reaction between H 2 S and PMo 12 accompanied by the increased reduction degree of Mo 6+ in PMo 12 . After five adsorption-regeneration cycles, PMo 12 @UiO-66@H 2 S-MIP-β-CD still exhibited ideal removal efficiency. The excellent desulfurization performance is mainly ascribed to the selective adsorption role of H 2 S-MIP-β-CD and oxidative removal ability of PMo 12 . This work provides a valuable reference for the directional design of high-capacity functional adsorbents for room-temperature desulfurization.