Interface modulation of Mn-N4-C with optimized oxygen-containing functional groups for highly efficient mercury adsorption

Jisai Chen; Zhijie Huang; Yongxian Zhou; Jiaxing Li; Sun Hu; Wenjun Huang; Zan Qu

doi:10.1016/j.jhazmat.2023.132498

Interface modulation of Mn-N₄-C with optimized oxygen-containing functional groups for highly efficient mercury adsorption

J Hazard Mater. 2024 Jan 5:461:132498. doi: 10.1016/j.jhazmat.2023.132498. Epub 2023 Sep 6.

Authors

Jisai Chen¹, Zhijie Huang², Yongxian Zhou¹, Jiaxing Li³, Sun Hu¹, Wenjun Huang², Zan Qu²

Affiliations

¹ CSSC Nanjing Luzhou Environm Protect Co Ltd, Nanjing 210039, China.
² School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China. Electronic address: lagow_lee@sjtu.edu.cn.

PMID: 37722322
DOI: 10.1016/j.jhazmat.2023.132498

Abstract

To achieve enhanced capture performance of industrial gaseous mercury pollution in heterogeneous reactions, the directed construction of an active reaction interface is particularly critical. Here, we developed atomically dispersed manganese confined within a carbon framework doped with heteroatoms (Mn-N₄-C) for strengthening the adsorption of elemental mercury at the interface. The results demonstrate that the adsorption performance of Mn-N₄-C is primarily determined by the surrounding coordination environment of individual metal sites. Due to the unique axial-coordination microenvironment, Mn-N₄-C with abundant oxygen-containing functional groups (Mn-N₄-C(EDA)) exhibits excellent affinity towards elemental mercury, with an adsorption capacity of up to 29.5 mg/g surpassing the most carbon-based materials. Furthermore, it also exhibits excellent tolerance towards various industrial flue gas conditions, performing an adsorption capacity of 16.4 ± 0.2 mg/g within the wide temperature range of 20-200 °C and being promoted by the NO, HCl and H₂O, which facilitates practical industrial applications. Theoretical simulations further indicate that the bonding between individual Mn and oxygen sites significantly enhances the mercury adsorption capability of Mn-O-N₄ sites, benefiting from the optimization of manganese's electronic structure by oxygen-containing species. Therefore, this study presents a multitude of opportunities for enhancing the adsorption of elemental mercury at interfaces through the directed modulation of metal-oxygen bonds(M-O).

Keywords: Adsorption; Elemental mercury; Flue gas; Interface modulation; Oxygen functional groups.