Mercury removal from flue gas using UiO-66-type metal-organic frameworks grafted with organic functionalities

UiO-66-type metal-organic frameworks (MOF) grafted with organic functionalities (–Br, –NO2 and –NH2) are introduced to investigate the elemental mercury (Hg0) removal from flue gas, and the effect for adding linkers on Hg0 removal is discussed. Results indicated that added functional groups did not alter the original topology of adsorbents, although their size and morphology varied. Adding –NH2 and –NO2 functional groups was detrimental for the thermal stability of UiO-66 except for -Br functional group, and grafted -Br itself was also stable. The Hg0 removal ability of UiO-66 was not significantly changed by grafting –NH2 and –NO2. The grafted -Br was beneficial for Hg0 capture, and the Hg0 removal performance of UiO-66-Br increased with increasing oxygen content and temperature. Furthermore, the mechanism of Hg0 capture was studied.