Efficient mercury removal at low temperature in flue gas with metal-organic frameworks modified by iodine

To enhance mercury removal efficiency at low temperature in flue gas , UiO-66-NH 2 framework was functionalized using halogen group via a diazotization process. -NH 2 was successfully replaced by halogen groups, and diazotization process had little impact on the morphology and the structural information of UiO-66-NH 2 , indicated UiO-66-X (Cl, Br, I) had an excellently chemical stability. Hg 0 capture experiments indicated added iodine (I) functional group was the most effective compared with chlorine (Cl) and bromine (Br). UiO-66-I can reach nearly 100% Hg 0 removal efficiency at 25–150 ℃，and the difference was the duration time for high performance. Moreover, oxygen played an important role for Hg 0 removal, which could be activated by the halogen functional group and then reacted with Hg 0 , finally existed on the adsorbent in the form of UiO-66-X … Hg-O. Furthermore, adsorption kinetic analysis indicated mercury adsorption at surface active sites was the rate controlling step .