Mechanism study of enhanced interaction between gaseous elemental mercury and hydroxylated UIO-66

Zhou, Changsong; Zhu, Wenxin; Chang, Xiong; Ding, Ding; Zhang, Tingting; Chen, Jiamin; Wu, Hao; Yang, Hongmin; Sun, Lushi

Mechanism study of enhanced interaction between gaseous elemental mercury and hydroxylated UIO-66

2020

Novel hydroxylated UIO-66 for gaseous elemental mercury (Hg⁰) removal has been considered to be an emerging method because of its economical and reusable property. Density functional theory studies were investigated to reveal the enhanced heterogeneous interaction mechanisms between mercury and hydroxylated UIO-66 with and without the presence of H₂O₂ vapor. The adsorption and dissociation of H₂O₂ and the generation mechanism of surface hydroxyls on UIO-66 were investigated. Results indicated that H₂O₂ preferred to disconnect the O–O bond followed by the generation of two hydroxyls in the presence of H₂O₂. The hydroxyl adsorbed on UIO-66 and formed the UIO-66 hydroxylation product. The interaction performances between Hg⁰, H₂O₂, and UIO-66 as well as the interaction performances between Hg⁰ and hydroxylated UIO-66 systems were both evaluated through binding energy and the Mulliken charge analysis. Interacted energies indicated thermodynamically favorable processes of Hg–OH formation on hydroxylated UIO-66. The Mulliken charge changes revealed an oxidative process of mercury.

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