Molecular singlet delta oxygen quenching kinetics in the EOIL system

Kinetics of oxygen species in an electrically driven singlet oxygen generator

“…They observed rapid quenching of O 2 (a 1 ∆) in O( 3 P)/O 2 /O 3 mixtures. It was found that the addition of Ar had no effect on the rate of O 2 (a 1 ∆) deactivation, whereas the addition of He and CO 2 decreased the quenching rate [19,20], in contradiction with expectations based on the 3BD mechanism. Attempts to model the fast decay using the 3BD mechanism yielded a rate constant of O 2 1 k =(1.1±0.1)×10 -31 cm 6 /s, which was inconsistent with the results of the flowing afterglow experiments.…”

“…In these studies the presence of He and/or CO 2 as the third body actually reduced the deactivation rate [19][20][21]. There are several experimental observations [19][20][21][22][23][24][25][26][27] showing that singlet oxygen is efficiently quenched by vibrationally excited ozone. Consequently, it is expected that reaction 3 will have a noticeable effect on the singlet oxygen production in discharge O 2 (a 1 ∆) generator given that oxygen atoms and molecules are abundant species in this device.…”

“…The kinetic model included reactions 1-12 listed in Table 1. For the post-discharge kinetics in experiments reported in [33], the heterogeneous processes (19) O( 3 P) + wall → ½O 2 (X 3 Σ) + wall (20) had a significant impact on O 2 (a 1 ∆), O( 3 P) and O 3 kinetics and they were added to our model. The removal rate of oxygen atoms on the unit surface area s O j (atom cm -2 sec -1 ) is as follows:…”

“…Vasiljeva et al [18] found that the O 2 (a 1 ∆) quenching rate in the discharge afterglow increases with oxygen pressure much faster than predictions based on the two-body quenching due to the components of an oxygen containing plasma (O, O 2 , O 3 etc.). They suggested that the faster deactivation of singlet oxygen at higher pressures was due to a three-body deactivation (3BD) process (reaction 1 in Table 1 [19,20] attempted to measure the rate constant of reaction 1 using pulsed laser photolysis of O 2 /O 3 mixtures at 248 nm to produce oxygen atoms and O 2 (a 1 ∆) molecules. They observed rapid quenching of O 2 (a 1 ∆) in O( 3 P)/O 2 /O 3 mixtures.…”

“…Rawlins et al [27] reported an estimated rate constant for quenching of O 2 (a 1 ∆) by ozone that has two or more quanta of the stretch modes to be in the range 10 -11 -10 -10 cm 3 s -1 . Recently [4,[19][20][21] …”