钯氢化物同位素分离因子的理论计算与实验测定

Theoretical Calculation and Experiment Determination of Isotopic Separation Factor in Palladium Hydrides

根据理想溶液模型计算了PdHxDy 的解吸等温线和氕氘分离因子 (α) ,实验研究了α与氢钯比 (r)、温度 (T)和固相氕 (H)的原子摩尔分数 (xH)的关系 ,并将理论计算与实验结果及文献数据进行了比较分析。结果表明 ,Pd (H +D)体系的离解压随xH 增加呈现出类似双曲线的单调非线性减小 ;在坪台区时 ,离解压与总的氢钯比 (r)无关 ;当r≥ 0 .6时 ,离解压随xH 增加而减小的趋势更为明显。PdHxDy 的分离因子的计算值随xH 增加而减小的趋势不及实验结果明显 ,当xH 越大 ,α减小越明显 ;xH 相同时 ,坪台区的α与r无关 ,但 β相 (r≥ 0 .6)的α随r的增加而增加。分离因子随着温度升高以指数函数下降。当xH→ 0和xH→ 1时 ,α的计算值分别为 2 .6和 2 .1。

The desorption pressure composition isotherms and separation factor between protium with deautium in PdH x D y were calculated on base of the ideal solution model. The relationship between separation factor with the atomic ratio of hydrogen to palladium, temperature and the atomic fraction of protium in solid phase were investigated by experiment. And the results from calculation and experiment and reference were compared each other and analyzed collectively. The desorption pressure of palladium hydrides decreases like as hyperbolic function accompanying with the increasing atomic fraction. In plateau range, the desorption pressure has nothing to do with the atomic ratio of hydrogen to palladium, but in hydrides phase, it decreases apparently accompanying with the increasing atomic ratio of hydrogen to palladium. The calculated separation factor in PdH x D y decreases along with the increasing atomic fraction of protium in solid phase, and it decreases faster when the atomic fraction of protium in solid phase is closer to 1.0, but this decreasing trend is not so apparent as the experiment result. At one same atomic fraction of protium in solid phase, the separation factor in plateau range has nothing to do with the atomic ratio of hydrogen to palladium, but in hydrides phase, it increases along with the above atomic ratio. The separation factor decreases as exponential function accompanying with increasing temperature. The limit value of separation factor from calculation is 2.6 for H→0 and 2.1 for H→1, respectively, which is consistent with the data from experiment and reference.