Development of Ultra High-Temperature Oxide Proton Conductive Solid Electrolyte

首先对传统质子导体CaZrO3（+In）在高温区的缺陷结构进行了详细的研究。在此基础上，提出了一种补偿氧化离子传导效应的新方法。采用该方法设计的氢气传感器系统样机已制成，并在实验室和实际装置上进行了测试。该系统作为金属熔炼过程的监控工具，具有良好的性能。为了寻找可在高温下使用的质子导体，研究了氢在铝酸镁尖晶石单晶中的行为。从红外吸收光谱中观察到OH伸缩振动的存在，确定了氢以质子的形式溶解到富铝尖晶石中。由溶解速率测定氢的化学扩散系数远小于传统的钙钛矿型质子导体。由于没有观察到H/D同位素对电导率的影响，证实了溶解质子的运动对电导率的贡献很小。从观察到的铝液超高氢溶解度的奇异现象出发，提出了铝基质子存在的可能性。建议指挥。因此，对氢在镁掺杂α -氧化铝单晶中的溶解进行了广泛的研究。从红外吸收的结果，证实氢溶解为一个可移动的质子。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。以Mg掺杂的烧结多晶氧化铝为材料，用电动势法测定了质子输运数。在氢气气氛中，即使温度为l473K，测定值也大于0.5。结果表明，掺杂mg的α -氧化铝是最佳的高温质子导电固体电解质材料。并对采用该电解质的氢传感器进行了性能测试，取得了良好的效果。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