Development of Ultra High-Temperature Oxide Proton Conductive Solid Electrolyte

本文首先详细研究了传统质子导体CaZrO_3（+In）在高温区的缺陷结构。在此基础上，提出了一种新的补偿方法，以补偿在较高温度范围内变得显著的氧离子导电效应。采用该方法设计的氢气传感器原型系统已在实验室和实际工厂进行了测试。为了寻找在更高温度下使用的质子导体，研究了氢在镁铝尖晶石单晶中的行为。从IR吸收光谱中观察到的OH伸缩振动的存在，确定氢作为质子的类型溶解到富氧化铝尖晶石中。由溶解速率确定的氢的化学扩散系数远小于常规的氢扩散系数 ...更多信息 钙钛矿型质子导体。由于未观察到电导率的H/D同位素效应，证实了溶解质子的运动对电导率的贡献很小，从观察到的铝熔体超高氢溶解度的奇怪现象考虑，提出了铝基质子导体的可能性。因此，氢溶解到镁掺杂的α氧化铝单晶中被广泛研究。根据IR吸收的结果，确认氢作为可移动质子溶解。在电导率测量中观察到明显的H/D同位素效应。并确定了质子传导的优势。用电动势法测定了掺镁烧结多晶氧化铝的质子输运数。在氢气氛中，即使在1473K下，其测定值也大于0.5，表明Mg掺杂α-Al2O3是最适合于高温质子导电固体电解质的材料。并对用该电解液制作的氢敏元件进行了性能测试，取得了良好的结果。少

The defect structure of the conventional proton conductor CaZrO3(+In) in the high temperature region was studied in detail at first. According to the results, a new method to compensate the effect of the oxide ion conduction, which become remarkable in higher temperature range, was developed. The prototype hydrogen sensor system designed adopting this method was made and tested in the laboratory and the practical plant. The high performance of the system as the monitoring tool for the metal melting process was confirmed.In order to find the proton conductor usable in higher temperatures, the behavior of hydrogen in the single crystal of magnesium aluminate spinel was studied. From the existence of OH stretching vibration observed in the IR absorption spectrum, the dissolution of hydrogen into the alumina-rich spinel as the type of proton was ascertained. The chemical diffusion coefficient of hydrogen determined from the dissolution rate was found far smaller than those of conventional … More perobskite-type proton conductors. As the H/D isotope effect in the electrical conductivity was not observed, it was confirmed that the contribution of the movement of the dissolved proton to the electrical conduction was very small.From the consideration on the curious phenomena observed concerning the extra high hydrogen solubility of molten aluminum, the possibility of alumina-base proton.conductor was suggested. Therefore, the hydrogen dissolution into the single crystal of Mg-doped alpha alumina was studied extensively. From the result of IR absorption, hydrogen was confirmed to dissolve as a movable proton. A clear H/D isotope effect was observed in the electrical conductivity measurement. And the predominancy of the proton conduction was ascertained. Using Mg doped sintered polycrystalline alumina, the proton transport number was determined by EMF method. The determined value in hydrogen atmosphere was more than 0.5 even at the temperature l473K.It was found that Mg-doped alpha alumina was the best material as a proton conducting solid electrolyte for high temperature use. The performance of the hydrogen sensor using this electrolyte was also tested and good results were obtained. Less