Effects of metals doping on the removal of Hg and H2S over ceria

Abstract

The effects of Mn and Fe doping into the CeO2(111) surface on the simultaneous removal of Hg and H2S was investigated, a density functional theory calculation with the on-site Coulomb interaction taken into account was adopted. The adsorptions of Hg-containing species on perfect CeO2(111), Mn/CeO2(111) and Fe/CeO2(111) surfaces were studied, the results showed that Mn and Fe dopants facilitated Hg adsorption, and more charge transferred from Hg atom to the metal doped surfaces; HgS preferred to adsorb on the perfect surface with the dissociated mode, while with the molecular mode on Mn/CeO2(111) and Fe/CeO2(111) surfaces. The reaction mechanism show that the dissociated S by H2S can easily react with Hg leading to the formation of HgS on Mn/CeO2(111) and Fe/CeO2(111) surfaces, which is crucial to capture mercury.