Density Functional Theory Study of Mercury Adsorption on CuS Surface: Effect of Typical Flue Gas Components

• Published in: Energy & fuels 2019-02, Vol.33 (2), p.1540-1546
• Main Authors: Li, Hailong, Feng, Shihao, Yang, Zequn, Yang, Jianping, Liu, Suojiang, Hu, Yingchao, Zhong, Lan, Qu, Wenqi
• Format: Article
• Language: English
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.8b03585

Copper sulfide (CuS) has been proved to be a potential alternative to traditional sorbents for control of elemental mercury (Hg0) emissions downstream of the wet flue gas desulfurization (WFGD) systems. However, the detailed reaction mechanisms involved in Hg0 adsorption over CuS surface are still unclear. The density functional theory was applied to investigate Hg0 adsorption over CuS(001) surface. The results indicated that the chemisorption mechanism was responsible for Hg0 adsorption over CuS(001) surface. The formation of Hg–S and Hg–Cu bonds was confirmed by depicting the projected densities of states profiles. The binding energies of Hg0 suggested that the crystal surface with two sulfur terminations [labeled CuS(001)–S-2] exhibited a better Hg0 adsorption activity than the crystal surface with copper and sulfur terminations [labeled CuS(001)–Cu/S]. Moreover, the adsorption of the flue gas components downstream of WFGD (oxygen, sulfur dioxide, and water vapor) was studied to understand the effect of the flue gas components on Hg0 adsorption over CuS surface. The slight competitive adsorption further identified the negligible influence of oxygen, sulfur dioxide, and water vapor on Hg0 adsorption in previous experiments.