CoS nanoparticles-embedded porous carbon: A highly efficient sorbent for mercury capture from nonferrous smelting flue gas.

In this study, a novel CoS nanoparticles-embedded porous carbon (CoS-PC) was designed as an effective reusable sorbent for Hg capture from smelting flue gas. Some flue gas components can create more active sites on CoS-PC for Hg adsorption, but compete with Hg for the same sulfur sites over nano CoS/CoS (CoS) and CoS/CoS embedded porous carbon (CoS-PC), which can be ascribed to the difference in crystal structure between CoS and CoS/CoS. Therefore, CoS-PC shows much better Hg capture ability than CoS and CoS-PC under smelting flue gas. O, SO and HCl improve Hg adsorption on CoS-PC mainly through creating Co site, but HO has neglectable effect on Hg capture. CoS-PC shows a remarkably large Hg adsorption capacity of 43.18 mg/g, which is greatly higher than the representative metal sulfides for Hg removal from smelting flue gas. During Hg adsorption, Co is the primary site to directly interact with Hg, and the adsorbed mercury exists as HgS. CoS-PC exhibits an excellent recyclability for capturing Hg, which is mainly assigned to the replenishment of consumed Co site by O, SO and HCl. Therefore, CoS nanoparticles-embedded porous carbon is an efficient, sustainable and highly recyclable sorbent for Hg recovery from smelting flue gas.