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Effect of aluminum vacancies on the H 2 O 2 or H 2 O interaction with a gamma‐AlOOH surface. A solid‐state DFT study

2019; Wiley; Volume: 119; Issue: 13 Linguagem: Inglês

10.1002/qua.25920

1097-461X

Alexander G. Medvedev, Alexey A. Mikhaylov, Ivan Yu. Chernyshov, Mikhail V. Vener, Ovadia Lev, Petr V. Prikhodchenko,

Crystallography and molecular interactions

Abstract The adsorption of a single H 2 O 2 or H 2 O molecule on a family of periodic slab models of γ‐AlOOH is studied by solid‐state DFT. The single H 2 O 2 or Н 2 О molecule interacts with the perfect (010) slab by intermolecular hydrogen bonds (H‐bonds). In the models of γ‐AlOOH with oxygen and aluminum vacancies, H 2 O 2 or Н 2 О also forms covalent O∙∙∙Al bonds. The energies of covalent O∙∙∙Al and H‐bonds are estimated by a combined approach based on simultaneous consideration of the total binding energies with BSSE correction and empirical schemes of the Н‐bond energy evaluation. The O∙∙∙Al bond energy ranges from ~75 to ~156 kJ mol −1 . The total energy of H‐bond interactions in the case of H 2 O 2 exceeds that of Н 2 О by ~30 kJ mol −1 for all considered slab models. In contrast to Н 2 О, a H 2 O 2 molecule always forms two H‐bonds as the proton donor. The energy of these bonds noticeably increase on defect γ‐AlOOH surfaces in comparison with the perfect slab due to formation of short (strong) H‐bonds by adsorbed H 2 O 2 .