Molecular-level insights into mercury removal mechanism by pyrite.

Title Molecular-level insights into mercury removal mechanism by pyrite.
Authors Y. Yang; J. Liu; F. Liu; Z. Wang; S. Miao
Journal J Hazard Mater
DOI 10.1016/j.jhazmat.2017.10.011

Natural pyrite (FeS2) has been regarded as a kind of potential sorbents to control mercury emission from coal-fired power plants because of its low cost and high affinity between mercury and FeS2. Theoretical investigations based on density functional theory (DFT) were carried out to discern mercury adsorption, reaction and desorption mechanisms over pyrite surface. DFT calculation results indicate that Hg0 adsorption on FeS2(100) and FeS2(110) surfaces is dominated by physisorption and chemisorption mechanisms, respectively. Mercury atom interacts strongly with Fe atom on FeS2(110) surface through the atomic orbital hybridization and overlap. HgS is chemically adsorbed on FeS2(100) and FeS2(110) surfaces. Electron density difference analysis implies that the significant charge accumulation around sulfur atom of adsorbed HgS molecule is closely associated with the strong interaction between gaseous HgS and pyrite surface. The reaction pathway leading to the formation of gaseous HgS is a three-step process: Hg0?Hg(ads)?HgS(ads)?HgS. In the second step, the energy barrier of diatomic surface reaction between adsorbed Hg0 and S2- monomer is approximately 17kJ/mol. The third step is an endothermic process which requires an external energy of about 414.60kJ/mol to desorb the formed HgS, and is the rate-determining step.

Citation Y. Yang; J. Liu; F. Liu; Z. Wang; S. Miao.Molecular-level insights into mercury removal mechanism by pyrite.. J Hazard Mater. 2018;344:104112. doi:10.1016/j.jhazmat.2017.10.011

Related Elements


See more Iron products. Iron (atomic symbol: Fe, atomic number: 26) is a Block D, Group 8, Period 4 element with an atomic weight of 55.845. The number of electrons in each of Iron's shells is 2, 8, 14, 2 and its electron configuration is [Ar] 3d6 4s2. Iron Bohr ModelThe iron atom has a radius of 126 pm and a Van der Waals radius of 194 pm. Iron was discovered by humans before 5000 BC. In its elemental form, iron has a lustrous grayish metallic appearance. Iron is the fourth most common element in the Earth's crust and the most common element by mass forming the earth as a whole. Iron is rarely found as a free element, since it tends to oxidize easily; it is usually found in minerals such as magnetite, hematite, goethite, limonite, or siderite.Elemental Iron Though pure iron is typically soft, the addition of carbon creates the alloy known as steel, which is significantly stronger.


See more Sulfur products. Sulfur (or Sulphur) (atomic symbol: S, atomic number: 16) is a Block P, Group 16, Period 3 element with an atomic radius of 32.066. Sulfur Bohr ModelThe number of electrons in each of Sulfur's shells is 2, 8, 6 and its electron configuration is [Ne] 3s2 3p4. In its elemental form, sulfur has a light yellow appearance. The sulfur atom has a covalent radius of 105 pm and a Van der Waals radius of 180 pm. In nature, sulfur can be found in hot springs, meteorites, volcanoes, and as galena, gypsum, and epsom salts. Sulfur has been known since ancient times but was not accepted as an element until 1777, when Antoine Lavoisier helped to convince the scientific community that it was an element and not a compound.

Related Forms & Applications