磷酸二丁酯在2.0 mol/L HNO3介质中的水解动力学

通过红外光谱、气质联用和离子色谱等分析方法确定了磷酸二丁酯在后处理常见工况2.0 mol/L HNO₃下的反应产物主要为丁醇、丁酸、丙酸、磷酸一丁酯和磷酸根离子等。采用离子色谱定量分析测定了磷酸一丁酯和磷酸根离子的浓度与反应时间和温度的关系，计算了磷酸二丁酯水解反应的速率常数，并对测定数据进行了计算拟合。结果表明：在110~150 ℃范围内，磷酸二丁酯的水解速率随温度的升高呈指数增长，满足准一级反应动力学方程；110 ℃和150 ℃的一级水解速率常数分别为6.30×10^-3 s^-1和2.10×10^-1 s^-1，二级水解速率常数分别为3.10×10^-3 s^-1和1.98×10^-1 s^-1；一级水解反应的指前因子为9.38×10¹² s^-1，对应的活化能为111.0 kJ/mol，二级水解反应的指前因子为1.09×10¹⁶ s^-1，对应的活化能为135.2 kJ/mol。动力学计算值与实验值的误差在±9%以内。

Hydrolysis Kinetics of Dibutyl Phosphate in 2.0 mol/L HNO3 Medium

In this paper, the reaction products of dibutyl phosphate in 2.0 mol/L HNO₃ of spent fuel reprocessing condition were butanol, butyric acid, propionic acid, mono-butyl phosphate, and phosphate ion, etc., determined by infrared spectroscopy, GC-MS, and ion chromatography. The relationship between the concentration of mono-butyl phosphate and phosphate ion with the reaction time and temperature was determined by ion chromatography quantitative analysis, and the rate constants of the hydrolysis reaction of dibutyl phosphate were calculated and fitted. The results show that: the hydrolysis rate of dibutyl phosphate increases exponentially with the increase of temperature at the range of 110-150 ℃, which satisfies the quasi-first order kinetic equation. The first-order hydrolysis rate constants are 6.30×10^-3 s^-1 at 110 ℃ and 2.10×10^-1 s^-1 at 150 ℃, and the second-order hydrolysis rate constants are 3.10×10^-3 s^-1 at 110 ℃ and 1.98×10^-1 s^-1 at 150 ℃, respectively. For the first-order hydrolysis reaction, the pre-exponential factor is 9.38×10¹² s^-1, and the corresponding activation energy is 111.0 kJ/mol. For the second-order hydrolysis reaction, the pre-exponential factor is 1.09×10¹⁶ s^-1, and the corresponding activation energy is 135.2 kJ/mol. The error between the calculated kinetics values and the experimental values is within ±9%.