Novel Synergetic Effect of Fe and W in FeWx/TiO2 on Capturing High Concentrations of Gaseous Hg0 from Smelting Flue Gas: Adsorption Kinetics and Structure-Activity Relationship

In this work, a regenerable sorbent FeWSx/TiO2 was used to reclaim gaseous Hg-0 in smelting flue gas for centralized control. FeWSx/TiO2 exhibited excellent ability to adsorb Hg-0 with the adsorption rate of 25.0 mu g g(-1) min(-1). There was a novel synergetic effect of Fe and W in FeWSx/TiO2 for Hg-0 adsorption, and the rate of Hg-0 adsorption onto FeWSx/TiO2 was generally greater than the total of those onto FeSx/TiO2 and WSx/TiO2. The structure-activity relationship of FeWSx/TiO2 for Hg-0 capture was discovered according to the kinetic analysis. FeWSx/TiO2's capacity for Hg-0 adsorption was approximately dependent on the number of S-2(2-) on the surface. Meanwhile, the rate of adsorption of He onto FeWSx/TiO2 was proportional to the product of the number of S-2(2-) on the surface and the number of surface adsorption sites for the physical adsorption of gaseous Hg-0. Although S-2(2-) on FeSx/TiO(2)( )did not increase obviously after W incorporation, the adsorption sites on FeSx/TiO2 obviously increased due to the appearance of WS3. Therefore, the rate of adsorption of Hg-0 onto FeWSx/TiO was 1.8-2.3 times that on FeSx/TiO2.