NO3自由基与3种环醚的大气化学反应动力学研究

在自制的大气反应烟雾箱模拟实验装置中,利用相对速率法研究了3种工业常用溶剂四氢呋喃、1,3-二氧五环、1,4-二氧六环与NO3自由基在298 K±1 K和1.01×105 Pa条件下的反应,目的是通过了解这些挥发性有机化合物（volatile organiccompounds,VOCs）在大气中的降解反应动力学来评估这些化合物对环境可能造成的影响.利用配有氢火焰离子化检测器（FID）的气相色谱（GC）检测反应物浓度变化,测得NO3自由基与四氢呋喃的反应速率常数为（5.36±1.93）×10-15cm3·（molecule·s）-1,与文献报道值在误差范围内非常吻合,验证了实验装置和实验方法的可靠性.实验首次测定了298 K±1K和1.01×105 Pa条件下1,3-二氧五环以及1,4-二氧六环与NO3自由基反应的速率常数,分别为（1.84±0.70）×10-15cm3·（molecule·s）-1和（3.20±0.67）×10-16 cm3.（molecule·s）-1.利用所测反应速率常数估算这些化合物在大气中的平均寿命都在1 d甚至十几d,因此,其排放可能会对区域大气环境产生一定的影响.

Kinetic Studies on the Gas-phase Reactions of NO3 Radicals with Three Cyclic Ethers

Kinetics of the reaction of NO₃ radicals with tetrahydrofuran, 1, 3-dioxolane and 1, 4-dioxane at 298K±1K and 1.01×10⁵ Pa were investigated using a relative rate method in a self-made Teflon chamber. The objective of this study was to assess the possible impact of these volatile organic compounds (VOCs) on the environment by studying their atmospheric degradation kinetics. Using gas chromatograph with a flame ionization detector(GC/FID), the measured reaction rate constant for NO₃ with tetrahydrofuran was (5.36±1.93)×10^-15 cm³·(molecule·s)^-1, which is in good agreement with the reported values, indicating the reliability of our experiment setup and methods. The reactions of NO₃ radicals with 1, 3-dioxolane and 1, 4-dioxane were studied for the first time and the measured rate constants were (1.84±0.70)×10^-15 cm³·(molecule·s)^-1 and (3.20±0.67)×10^-16 cm³·(molecule·s)^-1, respectively. The atmospheric lifetimes of these compounds have also been estimated based on the measured rate constants, which indicate that emissions of these compounds may have an impact on regional atmospheric environment.