IR Study of Ozone Adsorption on SiO2

Ozone decomposition on Saharan dust: an experimental investigation

“…According to another FT-IR study of the same group on the interaction between O 3 and a partially hydrated TiO 2 surface (Bulanin et al, 1995b), at least three different types of surface sites for O 3 adsorption can be distinguished: (I) surface sites where O 3 is weakly bound to hydroxyl groups or by physisorption; (II) surface sites with weak Lewis acid character (unsaturated Ti IV ions) where O 3 is chemisorbed but remains intact with distorted geometry; and (III) strong Lewis acid sites where adsorbed O 3 molecules are sufficiently distorted that they dissociate into O 2 and O. O 3 adsorption to surface sites type I is completely reversible, as was shown for O 3 adsorption onto partially hydrated SiO 2 (Bulanin et al, 1994). In the present experiments, if reversible O 3 uptake to OH groups (surface sites type I) had played a role, O 3 desorption after O 3 uptake should have been observable, which was not the case.…”

“…A number of studies have been performed on the adsorption of O 3 onto various mineral oxides, using electron paramagnetic resonance, infrared spectroscopy and kinetic measurement techniques (Dhandapani and Oyama, 1997). The surfaces examined were among others: γ -Al 2 O 3 (Klimovskii et al, 1983;Bulanin et al, 1995a;Thomas et al, 1997), SiO 2 (Bulanin et al, 1994), TiO 2 (Bulanin et al, 1995a(Bulanin et al, , 1995b, CaO (Bulanin et al, 1997) and MgO (Bulanin et al, 1995a;Berlier et al, 2002). A few semi-quanitative studies on the interaction between ozone and authentic mineral dust have been published (Suzuki et al, 1979;Alebic-Juretic et al, 1992;Alebic-Juretic et al, 2000), and initial uptake coefficients for O 3 uptake onto synthetic and authentic minerals have been measured (Michel et al, 2002).…”

Natural zeolite reactivity towards ozone: The role of compensating cations

“…Ozone interaction with zeolite samples increases the intensities of the bands at 1052-1054 cm −1 and at 1405-1416 cm −1 ; which could be associated to ozone molecular adsorption and to active atomic oxygen, respectively. In particular, IR band around 1037 cm −1 has been associated to ozone adsorption on weak Lewis acid sites [21,23]. Moreover, a peak at 1380 cm −1 has been assigned to a stable surface oxide species due to a strong bond where the atomic oxygen was Scheme 1.…”

Radical-mediated adsorption: Ozone oxidation of passivated silicon

“…When an O 3 molecule impinges close to pre-existing surface hydroxyl, as investigated in trajectories similar to that depicted in Fig. 1d, we find that it has a high probability of being captured; the O A H bond rapidly reorients itself to form a hydrogen bond with one of the terminal oxygen atoms of O 3 [13]. Our calculations indicate that the hydrogen bond strength is approximately 0.1-0.3 eV, and topological analysis confirms the existence of a diagnostic critical point in the electron density (see [14] and references therein).…”