Investigation of Adsorption Behavior of Mercury on Au(111) from First Principles

Abstract

The structural and electronic properties of Hg, SO 2 , HgS, and HgO adsorption on Au(111) surfaces have been determined using density functional theory with the generalized gradient approximation. The adsorption strength of Hg on Au(111) increases by a factor of 1.3 (from −9.7 to −12.6 kcal/mol) when the number of surface vacancies increases from 0 to 3; however, the adsorption energy decreases with more than three vacancies. In the case of SO 2 adsorption on Au(111), the Au surface atoms are better able to stabilize the SO 2 molecule when they are highly undercoordinated. The SO 2 adsorption stability is enhanced from −0.8 to −9.3 kcal/mol by increasing the number of vacancies from 0 to 14, with the lowest adsorption energy of −10.2 kcal/mol at 8 Au vacancies. Atomic sulfur and oxygen precovered-Au(111) surfaces lower the Hg stability when Hg adsorbs on the top of S and O atoms. However, a cooperative effect between adjacent Hg atoms is observed as the number of S and Hg atoms increases on the perfect Au(111) surface, resulting in an increase in the magnitude of Hg adsorption. Details of the electronic structure properties of the Hg−Au systems are also discussed.

Oxidation mechanism of elemental mercury by HCl over MnO2 catalyst: Insights from first principles

“…A promising technology for efficiently and economically controlling the Hg 0 emission from flue gases is catalytic oxidation of Hg 0 to its Hg 2+ form that can be subsequently captured in downstream WFGD system. To date, selective catalytic reduction (SCR) catalysts [5][6][7], carbon-based catalysts [8,9], noble metals [10,11] and transition metal oxides catalysts [12,13] have been widely studied for Hg oxidation. Among these catalysts, MnO 2 -based catalysts have received lots of attention due to their high catalytic performance at low temperature for Hg removal [14,15].…”

Nobler than the Noblest: Noncubic Gold Microcrystallites

“…[23] In the case of Cu on Au, for instance,m ore than the lattice mismatch, it appears that the lattice anisotropy at the bc(o,t) facets makes the surface deposition of Cu unfavourable.S imilar arguments may be made with respect to other heteroatoms requiring definitive surface geometries for adsorption and, in general, for extended interaction. [23] In the case of Cu on Au, for instance,m ore than the lattice mismatch, it appears that the lattice anisotropy at the bc(o,t) facets makes the surface deposition of Cu unfavourable.S imilar arguments may be made with respect to other heteroatoms requiring definitive surface geometries for adsorption and, in general, for extended interaction.…”

Increased co-oxidation activity for mercury under hot and cold site coal power plant conditions – Preparation and evaluation of Au/TiO2-coated SCR-DeNOx catalysts

“…Fig.4 [40]. The importance of the mercury being adsorbed on the gold surface for the oxidation process has already been pointed out in literature [41].…”