Enhancing the catalytic oxidation of elemental mercury and suppressing sulfur-toxic adsorption sites from SO2-containing gas in Mn-SnS2

It is difficult to stabilize gaseous elemental mercury (Hg degrees) on a sorbent from SO2 -containing industrial flue gas. Enhancing Hg degrees oxidation and activating surface-active sulfur (S*) can benefit the chemical mercury adsorption process. A Mn-SnS2 composite was prepared using the Mn modification of SnS2 nanosheets to expose more Mn oxidation and sulfur adsorption sites. The results indicate that Mn-Sn-2 exhibits better Hg degrees removal performances at a wide temperature range of 100-250 degrees C. A sufficient amount of surface Mn with a valance state of Mn4+ is favorable for Hg degrees oxidation, while the electron transfer properties of Sn can accelerate this oxidation process. Oxidized mercury primary exists as HgS with surface S*. A larger surface area, stable crystal structure, and active valance state of each element are favorable for Hg degrees oxidation and adsorption. The Mn-SnS2 exhibits an excellent SO2 resistance when the SO2 concentration is lower than 1500 ppm. The effects of H2O and O-2 were also evaluated. The results show that O-2 has no influence, while H2O and SO2 coexisting in the flue gas have a toxic effect on the Hg degrees removal performance. The Mn-SnS2 has a great potential for the Hg degrees removal from SO2-( )containing flue gas such as non-ferrous smelting gas.