Studies of Hydrogen-pumping Function of Proton-conducting Ceramics and Their Applications

本研究的目的是阐明质子导电陶瓷的电化学氢泵的作用，并为氢泵在工业过程和科学仪器中的应用确立指导原则。此外，开发适合氢泵的新型质子导电陶瓷也是我们研究的目标之一。根据实验结果，详细研究了氢气气体电极反应以及使用质子导电陶瓷的氢泵的阳极和阴极的电极行为。明确了电极材料的微观结构、水蒸气含量和提高泵浦能力的工作温度。基于这些结果，我们成功地构建了一种高性能的氢泵，它可以在高于1Acm；-2的电流密度下电化学泵送氢气。将氢气的泵浦功能与质子导电陶瓷的氢敏功能相结合，设计了混合气中氢气分压调节器，并验证了其工作性能。氢泵被成功地应用于密闭容器的电化学除湿器和不需要氢标准物质的氢传感器。在此基础上，新合成了以Sr2YTaO6、LaSrAlO4、La&lt；5.8&Gt；WO&lt；11.7&gt；La_3NbO_7、LaSco_3、SrZrO_3等为基础的质子导电固体氧化物。

The objectives of this study are to clarify the function of electrochemical hydrogen pump of proton-conducting ceramics and to establish the guiding principles for applying the hydrogen pump to industrial process and scientific instruments. Also, the creation of new proton conducting ceramics suitable for the hydrogen pump is one of the aims of our study.Hydrogen gas electrode reaction and the electrode behavior of anode and cathode of the hydrogen pump using a proton-conducting ceramic were investigated in detail from the experimental results. The microstructure of electrode material, the content of water vapor and the operation temperature that would enable to enhance the pumping capacity could be clarified in this work. Based on these results, we succeeded in constructing a high performance hydrogen pump which could electrochemically pump the hydrogen gas at higher current density than 1Acm^<-2>.Combining the hydrogen-pumping function with the hydrogen-sensing function of proton-conducting ceramic, the regulator of hydrogen partial pressure in the gas mixture was devised and it was confirmed to work well. Hydrogen pumps were successfully applied to an electrochemical dehumidifier for closed vessels and the hydrogen sensors which need no hydrogen standard material. This kind of a pump showed the possibility of applying to denitration equipment for exhaust gas from internal combustion engines.Furthermore, several kinds of proton-conducting solid oxide based on Sr_2YTaO_6, LaSrAlO_4, La_<5.8>WO_<11.7>, La_3NbO_7, LaScO_3, SrZrO_3 etc.were newly synthesized.