Effect of SO3 on elemental mercury adsorption on a carbonaceous surface

• Published in: Applied surface science Vol. 258; no. 22; pp. 8853 - 8860
• Main Authors: He, Ping, Wu, Jiang, Jiang, Xiumin, Pan, Weiguo, Ren, Jianxing
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2012; Elsevier
• Subjects: Adsorption; Benzene; Carbon; Carbonaceous surface; Computer simulation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Energy gap; Exact sciences and technology; Mercury; Molecular orbitals; Physics; SO3; Surface chemistry; Adsorption; Carbonaceous surface; Mercury; SO3; SO; Transition elements
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.05.104

► SO3 competes for the active sites on the carbonaceous surface and inhibits Hg adsorption. ► SO3 suppresses the activity of its next-nearest-neighbor carbon atom. ► SO3 cannot directly provide the active sites. ► SO3 decreases the unoccupied frontier molecular orbitals of the carbonaceous surface. ► SO3 increases the LUMO–HOMO energy gap of the carbonaceous surface. The effect of SO3 on elemental mercury adsorption on a carbonaceous surface is investigated by the density-functional theory calculations. A nine-fused benzene ring model is employed to represent the carbonaceous surface. The edge atoms on the upper side of the model remain unsaturated to simulate the active sites for reaction. All of the possible approaches in which SO3 is adsorbed on the carbonaceous surface are conducted to evaluate their effects on Hg adsorption. The results indicate that the carbonaceous surface is energetically favorable for SO3 adsorption, which causes that SO3 competes for the active sites on the carbonaceous surface. But adsorption of SO3 decreases the adsorption capacity of the carbonaceous surface for Hg0 since SO3 suppresses the activity of its next-nearest-neighbor carbon atom and negatively affects on the frontier molecular orbitals and LUMO–HOMO energy gap of the carbonaceous surface.