Computational insights into interactions between Hg species and α-Fe 2O 3 (0 0 1)

Abstract

First-principle calculations based on Density Functional Theory were performed to investigate the binding mechanisms of mercury species on α-Fe 2O 3 (0 0 1) surface. This is crucial in demonstrating the contribution of α-Fe 2O 3 existing in fly ash for mercury removal. It has been determined that Hg 0 is adsorbed on the α-Fe 2O 3 (0 0 1) surface with physisorption mechanism. The oxidized forms of HgCl and HgCl 2 can be adsorbed on α-Fe 2O 3 (0 0 1) dissociatively or non-dissociatively. In the case of dissociative adsorption, a close examination of the energy diagram indicates that HgCl may be favorable for the adsorption of Cl and desorption of Hg. The dissociation of HgCl 2 with the binding of Cl and HgCl on the surface is possibly the dominant interaction pathway.