First Principle Study of the Adsorption of Mercury on the Carbon Surface

The interactions of mercury with the carbon surface are investigated by performing the density functional electrical structure calculation. The five different carbon groups bonded with the elemental hydrogen and chlorine are proposed to build the carbon surfaces. The calculations are presented for mercury sorption on both on-top (T) and sixfold-angle (A) sites. The adsorption energy curve reveals that the adsorptive capacity for mercury on the T or A site absorbed on the symmetrical carbon groups can be improved following the increasing size of molecules, which can not be suitable for the unsymmetrical carbon group structures. For the mercury on the A site, the carbon group with the different absorptive positions on the sixfold carbons usually have equal adsorption energy. Even though several carbon groups present the inequable cases, the differences remain a constant value. The conclusion is significant to design and operate the mercury emission control based on the carbon surface.