A study of interaction between hydrogen peroxide and silica gel by FTIR spectroscopy and quantum chemistry

The FTIR spectra of the silica xerogel–H2O2 composite, obtained by the sol–gel technique, were examined. To support interpretation of the experimental data, vibrational frequencies were calculated using density functional theory (DFT) and B3LYP functional for low-molecular-weight models of solvated silica gel: H4SiO4–H2O2–H2O and [(HO)3SiOSi(OH)3]–H2O2. The role of water in stabilizing the hydrogen peroxide adsorbed on silica surface was discussed. The interaction energies of complexes (1:1) formed between hydrogen peroxide and disilicic acid molecule were calculated employing different levels of theory (HF, B3LYP and MP2) and the 6-31++G(d,p) basis set. It was found that owing to its favorable geometry, hydrogen peroxide may form relatively strong hydrogen bond to oxygen of the siloxane bridge, Si–O–Si, of disilicic acid.