Abstract Due to its low cost, rich resource reserve, and high affinity for gas-phase mercury, zinc selenide has been investigated as a promising sorbent to control mercury emission. In order to gain molecular level insights into the adsorption mechanism, density functional theory (DFT) calculations were applied to the process of mercury adsorption on the (1 1 0) surface of ZnSe. Our results indicated that chemical adsorption played a crucial role in the Hg0 adsorption on the ZnSe (1 1 0) surface. Mercury atoms interacted energetically with surface Zn atoms through the interactions between atomic orbitals. The proposed process of transformation of Hg to HgSe can be described in three steps: i.e., Hg0 → Hg (ads) → HgSe (ads) → HgSe. The effects of SO2, H2O, and HCl on the adsorption of Hg0 on the surface of ZnSe were also investigated. SO2, H2O, and HCl are able to be chemisorbed on the surface of ZnSe (1 1 0) with the highest binding energies of −43.58 kJ/mol, −72.23 kJ/mol, −52.93 kJ/mol, respectively. Moreover, SO2 shows a dual effect on Hg0 binding, while H2O and HCl may suppress Hg0 adsorption on the ZnSe (1 1 0) surface. Theoretical study suggested that ZnSe sorbent has an excellent potential for the efficient removal of gas-phase mercury.

中文翻译：

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硒化锌有效固定气相元素汞的分子水平见解

摘要 硒化锌成本低、资源储量丰富、对气相汞的亲和力高，被研究作为一种有前景的汞排放控制吸附剂。为了在分子水平上深入了解吸附机制，将密度泛函理论 (DFT) 计算应用于 ZnSe (1 1 0) 表面上的汞吸附过程。我们的结果表明，化学吸附在 ZnSe (1 1 0) 表面上的 Hg0 吸附中起关键作用。汞原子通过原子轨道之间的相互作用与表面锌原子发生能量相互作用。提议的将 Hg 转化为 HgSe 的过程可以描述为三个步骤：即 Hg0 → Hg (ads) → HgSe (ads) → HgSe。还研究了 SO2、H2O 和 HCl 对 Hg0 在 ZnSe 表面吸附的影响。二氧化硫、水、和 HCl 能够化学吸附在 ZnSe (1 1 0) 表面，结合能最高，分别为 -43.58 kJ/mol、-72.23 kJ/mol、-52.93 kJ/mol。此外，SO2 显示出对 Hg0 结合的双重影响，而 H2O 和 HCl 可能会抑制 Hg0 在 ZnSe (1 1 0) 表面的吸附。理论研究表明，ZnSe 吸附剂在有效去除气相汞方面具有出色的潜力。