High-Temperature Reactions of Ozone with Bromine Behind Shock Waves. Rate Constant for the Reaction BrO+BrO→2Br+O₂

Abstract

A mixture of ozone and bromine, diluted by argon, was heated by reflected shock waves in a shock tube to the temperature range of 600–1100 K and the pressure range of 3.5–5.5 atm. From the concentration profiles of the BrO radical, the rate constant k ₁ for the reaction BrO+BrO→2Br+O₂ was determined as

$${k_1}/c{m^3}molecul{e^{ - 1}}{s^{ - 1}} = (1.9 \pm 0.1) \times {10^{ - 12}}\exp [ + (42 \pm 13)/T]$$

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A model calculation was carried out for the reactions of ozone with bromine. The results showed that bromine catalytically decomposed ozone in the chain cycle formed by the reactions BrO+BrO→2Br+O₂ and O₃+Br→-BrO+O₂, but that this acceleration effect of bromine fell with increasing temperature.