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

The adsorption of a single H₂O₂ or H₂O molecule on a family of periodic slab models of γ‐AlOOH is studied by solid‐state DFT. The single H₂O₂ or Н₂О molecule interacts with the perfect (010) slab by intermolecular hydrogen bonds (H‐bonds). In the models of γ‐AlOOH with oxygen and aluminum vacancies, H₂O₂ or Н₂О 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 H₂O₂ exceeds that of Н₂О by ~30 kJ mol⁻¹ for all considered slab models. In contrast to Н₂О, a H₂O₂ 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 H₂O₂.