α,β-蒎烯气相臭氧化速率常数的测定

Determination of Rate Constants of Gas-phase Reactions of α-Pinene and β-Pinene with Ozone

对α 蒎烯、β 蒎烯和O3的大气反应进行了初步实验室模拟 ,利用长光程傅里叶变换红外光谱技术结合相对速率法测得在 1 0× 10 5Pa,2 96± 3K条件下 ,α 蒎烯、β 蒎烯和O3气相反应的速率常数分别为2 83× 10 17cm3·molecule-1·s-1和 1 4 8× 10 17cm3·molecule-1·s-1。

pinene and β-pinene are the most dominating species among natural terpenes.Terpenes are mainly emitted from forest trees,flowers and grass.In the lower troposphere terpenes can react fast with OH radical,ozone,NO 3 radical and ground state oxygen atom.These reactions may contribute to the occurring of aerosols,peroxides (hydrogen peroxide and organic peroxide),carbon cycle (mainly CO),acid rain (organic acids,NO - 3 and SO 2- 4),ozone and active radicals such as OH radical.Reactions with ozone occur both in the daytime and in the night.The study in this field in China began in the late 1980.The main work focus on the source emission and the experimental simulation has just started.It is most of our group′s work.In this paper preliminary experimental simulation of the gas-phase reactions of α-pinene and β-pinene with ozone were carried out in the quartz chamber.The rate constants of these reactions were measured using long-path Fourier transform infra-red combined with relative rate constant method.And the rate constants for the gas-phase reactions of α-pinene,β-pinene with ozone were determined as 2 83×10 17 cm 3·molecule -1 ·s -1 and 1 48×10 17 cm 3·molecule -1 ·s -1 at 1 0×10 5 Pa and 296±3 K.The results are quite similar to the data from Atkinson group.No cyclohexane was added to the reaction system during the measurement to restrain the formation of OH radical.The formation of OH radical could not be quantified,so that the effect of subsidiary reactions induced by OH radical has not been calculated.In the later simulation study and model this effect should be considered.