Chalcogen-based materials have been confirmed to possess large adsorption capacities for gaseous elemental mercury (Hg-0) from SO2-containing flue gas. However, the interface reaction mechanisms and the interfacial stability are still ambiguous. Here, we selected some commonly used chalcogen-based sorbents (e.g., X, ZnX, CuX. X = S, Se) to investigate the in-depth reaction mechanisms. The adsorption capacities, structure effect on thermal and surface mercury stability, and interfacial reaction mechanism in the absence/presence of SO2 were evaluated. The experimental results indicated that Cu-chalcogenide had higher Hg-0 adsorption capacity and surface Hg-X bonding stability compared with zinc one, while they exhibited an opposite degree of thermal stability. Moreover, all the chalcogenides showed well SO2 tolerance but with a slight difference. Chalcogenides with the same crystal structures, like ZnX or CuX, exhibited similar properties in stability and interfacial Hg-0 and SO2 reaction mechanism. X in chalcogenides have a better affinity to mercury, while in the Hg-0 capture process, the existence of multivalent metal elements (like Cu2+ and Cu+) can faster the Hg-0 oxidation for the further chemical-adsorption. This work provides a basic understanding of the application for efficiently enriching and recycling gaseous Hg-0 from industrial SO2-containing flue gas. (C) 2020 Elsevier Inc. All rights reserved.