Explicit solvation effects on low-index Fe surfaces and small particles as adsorbents of Arsenic species: a DFT study

• Published in: Theoretical chemistry accounts 2021-06, Vol.140 (6), Article 67
• Main Authors: Tobón, Leslie L. Alfonso, Branda, María M.
• Format: Article
• Language: English
• Subjects: Adsorbents; Arsenic; Atomic/Molecular Structure and Spectra; Charge transfer; Chemistry; Chemistry and Materials Science; Density functional theory; Inorganic Chemistry; Nanoparticles; Organic Chemistry; Physical Chemistry; Regular Article; Solvation; Substrates; Theoretical and Computational Chemistry
• ISSN: 1432-881X; 1432-2234
• DOI: 10.1007/s00214-021-02767-4

Density functional theory (DFT) calculations were carried out on hydroxylated and solvated (H&S) Fe substrates. Fe (110) and (111) extended surfaces as well as clusters of 32 and 59 atoms, and a nanoparticle of 80 atoms were studied as adsorbent substrates of harmful As species. Arsenious (H 3 AsO 3 ) and arsenic (H 3 AsO 4 ) acids are physisorbed on the H&S Fe(110) but chemisorbed on the H&S Fe(111) surface. The open-packed plane of the (111) surface, with free active sites, allows better interaction with the acid molecules. The small hydroxylated cluster, Fe 32 , has shown the best activity as adsorbent of H 3 AsO 3 . Electronic charge transfer occurs not only from Fe atoms that directly interact with the acid molecule, but neighbouring Fe atoms are also oxidized. This work presents clear evidence that these spherical Fe aggregates, formed mainly by (111) faces and with an important percentage of low-coordination sites, are excellent adsorbent substrates of H 3 AsO 3 and should be considered as a reference to search for new supported catalysts. Graphical Abstract