Single-atom iron on penta-graphene assisted with non-bonding interaction as superior demercurizer: A DFT exploration

• Published in: Applied surface science Vol. 590; p. 153060
• Main Authors: Liu, Xiaoshuo, Wang, Rui, Huang, Tianfang, Geng, Xinze, Xu, Yifan, Chen, Cong, Wu, Chongchong, Ding, Xunlei, Duan, Yufeng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.2022
• Subjects: Density functional theory; Mercury adsorption; Non-bonding interaction; Penta-graphene; Reduced density gradient; Non-bonding interaction; Reduced density gradient; Density functional theory; Mercury adsorption; Penta-graphene
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2022.153060

Single-atom iron on penta-graphene platform with non-bonding interaction for elemental mercury adsorption. [Display omitted] •Single-atom Fe with N3 local environment on penta-graphene may be a new material for removal of elemental mercury under 520 K.•The decagonal hole on penta-graphene promotes the binding of single atom Fe to mercury through non-bonding interactions.•SO2 suppresses the adsorption of Hg0 on adsorbents by competitive adsorption arisen from its narrow FMO energy gap. Elemental mercury (Hg0) released from coal-fired power plants causes global concern. Magnetic adsorbents have attracted extensive attention due to their high adsorption performance, but carbon-based sorbents with magnetism for Hg0 removal are rarely studied. Having excellent adsorption activity, single-atom Fe adsorbents on penta-graphene (PG) substances might be promising magnetic materials for Hg0 removal. In this study, six different PG-based single-atom Fe adsorbents are designed by nitrogen doping, concluding that FeN3 on single-vacancy defective PG (Fe/SVN123) is an effective Hg0 adsorbent due to the larger adsorption energy (−0.87 eV) based on density functional theory (DFT) calculations. The electron density difference (EDD) and density of states (DOS) results demonstrate the existence of chemical bonding between Hg0 and the adsorbents. Non-covalent interaction (NCI) analysis verifies the important contribution of non-bonding interactions to adsorption strength. The temperature has an inhibitory effect on Hg0 adsorption. When the temperature reaches ∼520 K, Hg0 desorbs from Fe/SVN123, leading to adsorbent regeneration. The potentially detrimental effect of SO2 and NO on Hg0 adsorption on Fe/SVN123 is deeply discussed by configuration analysis and ab initio molecular dynamics (AIMD) simulation. This work enriches the fundamentals of single-atom catalysts (SACs) and opens up new insight into non-bonding interactions on SACs.