DFT studies of adsorption properties and bond strengths of H2S, HCN and NH3 on Fe(100)

Based on the first principle method of density functional theory (DFT), the adsorption properties, bond strengths of three molecules (H2S, HCN and NH3) in coke oven gas on the Fe-based surface were analyzed using the adsorption energy and the partial densities of states (PDOS). Consequently, the adsorption energy of H2S, NH3 and HCN molecules were the lowest respectively at h-H-down-p, t-H-up and Fourfold adsorption sites on Fe (1 0 0) surface. The adsorption energy of them is -2.298 eV, -0.984 eV and -1.920 eV individually. Furthermore, the consequence of densities of states evidences that there are hybrid peaks when the three molecules act on Fe-based surface, and new bonds are constituted between surface molecules and the substrate. The interaction energy between those molecules and the Fe(1 0 0) surface in turn is H2S > HCN > NH3, which also demonstrates that in coke oven gas H2S has the maximum sedimentation on the heat transfer surface.