Isotope Effects of Hydrogen Ion Transport in SrCeO_3(+Y_2O_3) and its Applications

对固体电解质SrCe_<0.95>Yb_<0.05>O_<3-6>中氢输运的同位素效应进行了研究，得到了以下结果：在电导率的测量中，在质子传导占主导地位的条件下观察到同位素效应。质子与氘核的电导率之比ROO<2>，这是由经典动力学理论估计的正态差。用西弗茨法测定氢的溶解度。与其他氧化物相比，该值非常大。氢的溶解度未见同位素效应。化学扩散系数由溶解度测量得到。同位素效应也未被检测到。认为这种效应是由氧离子空位的双极性扩散机制减弱的。通过热解吸分析，发现了低氧化学势条件下氢气溶解的新机制。研究了电解和不电解条件下氢气在样品薄壁上的渗透，并基于缺陷模型对其现象进行了分析。未电解时渗透轻氢与重氢之比为1.9，电解时为3.5。这些巨大的同位素效应不能从它们的流动性差异来解释。电极反应速度的差异是造成这些现象的原因。从以上结果确定了该电解质作为分离氢同位素的膜材料的可能性。

A research on the isotope effects in transport of hydrogen through the solid electrolyte SrCe_<0.95>Yb_<0.05>O_<3-6> was performed and the following results were obtained.1. On the measurement of electrical conductivity, an isotope effect was observed in the conditions where the proton conduction is dominant. The ratio of conductivity of proton to deuteron was ROO<2> which is normal difference estimated from the theory of classical kinetics.2. The solubility of hydrogen was measured by Sieverts method. The value was found very large compared to other oxides. The isotope effect in the solubility of hydrogen was not detected.3. The chemical diffusion coefficient was obtained from the solubility measurements. The isotope effect was also not detected. It was considered that the effect was reduced by the mechanism of ambipolar diffusion with oxygen ion vacancy.4. A new mechanism of solution of hydrogen was found in the condition of low oxygen chemical potential with the measurements of thermal desorption analysis.5. The permeation of hydrogen through the thin wall of the sample with and without electrolysis was studied and its phenomena was analyzed based on the model of defects. The ratio of permeated light hydrogen to heavy one was found 1.9 without electrolysis and was found 3.5 with electrolysis. These large isotope effects are not explained from the difference of their mobilities. The difference of the speed of electrode reaction was suggested as the reason of these phenomena.The possibility of this electrolyte as the material of membrane for the separation of isotope of hydrogen was ascertained from above results.