氘/氚化锆热解吸动力学同位素效应

Kinetic Isotope Effects of Desorption for Zirconium Deuteride and Tritide

在高真空金属系统上测定了氘化锆和氚化锆在恒容体系和775～875℃范围内热解吸的压力-时间等温线(p-t曲线),应用反应速率分析方法计算了各自在不同温度的速率常数。随着温度的升高,热解吸反应的速率增大,反应的平衡压随之增高。由速率常数计算得到氘化锆和氚化锆热解吸的表观活化能分别为(40.1±0.8)kJ/mol和(57.7±1.6)kJ/mol。氚化锆热解吸的表观活化能高于氘化锆热解吸的表观活化能,表现出显著的热解吸动力学同位素效应。

To meet the need of studying the difference of isotope effects for zirconium deuteride and tritide desorption,desorption p-t curves of zirconium deuteride and tritide were investigated at 775-875 ℃ by using the method of the reaction rate analysis in a constant volume system.The desorption rate constants of zirconium deuteride and tritide at different temperatures were determined.The rate of desorption is augmentable along with the increase of temperature and the equilibrium pressure of reaction is increased too.The activation energy of desorption for zirconium deuteride and tritide are（40.1±0.8） kJ/mol and（57.7±1.6） kJ/mol respectively.The desorption activation energy value of zirconium tritide is higher than that of zirconium deuteride and so there are remarkable kinetic isotope effects for desorption.