DFT Study of Antimony(V) Oxyanion Adsorption on 伪-Al2O3(11虆02)

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• 作者：Sai Kumar Ramadugu ; Sara E. Mason
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：August 13, 2015
• 年：2015
• 卷：119
• 期：32
• 页码：18149-18159
• 全文大小：821K
• ISSN：1932-7455

文摘

Density functional theory (DFT) calculations using periodic slab models are carried out to study the reactivity of aqueous Sb(OH)₆^{鈥?/sup> on model 伪-Al₂O₃(11虆02) surfaces. The strength of inner-sphere (specific) adsorption between Sb(OH)₆鈥?/sup> and surface models is ranked using DFT adsorption energies, E_ads. Trends in E_ads in terms of surface structure, adsorbing functional group identity, and oxyanion coordination to the surface are determined and analyzed in terms of geometry and electronic structure. The results show that not all Sb鈥揙_surf interactions involve the same type of Sb and O orbital interactions, which explains why trends in E_ads cannot be rationalized by universal Sb鈥揙 bond length鈥揵ond strength relationships. The DFT results show a preference for Sb(V) bidentate and tridentate geometries in which Sb bonds through the corners of AlO₆ groups in the surface. Less favorable adsorption involving edge sites is associated with adsorption-induced surface relaxations of oxygen groups from deeper layers of the surface.}