With Oxygen, Ozone, and the Hydroxyl Radical OH

Pb(C2H5)4 is subject to oxidation in gasoline in the presence of air, with the consequent formation of haze or precipitates [14, 16, 64]. It exerts an influence on gum formation in gasolines, mainly in aviation gasolines, with the result that leaded gasolines are somewhat less stable than unleaded fuels in normal storage [16, 64]. 

The oxidation of Pb(C2H5)4 by oxygen is autocatalytic and characterized by an induction period [22, 32, 37, 46] that is different in different hydrocarbons [22]. The temperature coefficient of the reaction rate is fairly high [46]. 

The autoxidation of Pb(C2H5)4 in hydrocarbons in the early stages proceeds in accordance with the equation N = ae (N = number of moles of O2 absorbed by the reaction mixture per mole of initial Pb(C2Hs)4, = autocatalysis factor, t = reaction time, a = proportionality factor) [48]. Another exponential equation was given earlier [22]. The temperature dependence of is described by the equation = 6.3x 10 s In the range 

The chain initiation is effected as a result of the spontaneous breakdown of Pb(C2H5)4 into radicals [22, 47, 59]. Proof for this assumption was obtained from a study of the oxidation of Pb(C2H5)4 in the presence of the oxidation inhibitor o-phenylenediamine. A linear relationship between the length of the induction period and the amount of inhibitor Is found to be associated with a constant rate of consumption of o-phenylenediamine during the induction period. This suggests stationary conditions of the process during the induction 

The oxidation rate depends on the material of the reaction vessel at the start of the process, the reaction rate in glass is higher than that in quartz [46]. 

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