LAUSR

Abstract The synergy effect of CuCl2 and FeCl3 impregnated into fly ash on mercury removal was investigated by experiment and density functional theory. The mercury removal efficiency of fly ash impregnated with a mixture of CuCl2 and FeCl3 was higher than that by single one of them. When the mass ratio of CuCl2 to FeCl3 was 3:1 and the sample temperature was between 140 °C and 160 °C, its mercury removal efficiency was the highest. Cu2+ contributes more than that of the Fe3+ in the mercury removal process. The density functional theory was applied to calculate their adsorption energy, electron transfer and energy barrier. The coexistence of Cu and Fe enhances the non-uniform charge distribution between the Cu, Fe and Cl. This non-uniform charge distribution accelerates the charge transfer of Hg0, which leads to a stable adsorption for Hg0. The synergistic effect of CuCl2 and FeCl3 can reduce the energy barrier during the Hg0 removal. This work provides an efficient approach for utilizing fly ash to remove Hg0 in coal combustion flue gas.