室温作動の安価なプロトン導電性固体電解質の開発

点击翻译按钮获取中文摘要

The objective of the study is to search for inorganic proton conductors operating at medium temperatures as 200-300℃. Three types of materials below were prepared and tested.(1) Water adsorbed ceramic particles were prepared by hydrolysis of alkoxide. In such a low-temperature synthesis, particle does not grow well and surface area becomes fairly large. The synthesized ceramics are TiO_2, A1_2O_3, ZrO_2, SiO_2, BaTiO_3. The conductivities measured at 90℃ fall into the range between 10^<-4> and 10^<-3>Scm^<-1>. The conductivities measured in the directions of temperature increase and decrease do not coincide at the same temperature. The latter is always smaller than the former. Protons may conduct via adsorbed water molecules and be significantly affected by their amount. Thus, it shows the hysteresis against temperature profile.(2) To increase the conductivity via adsorbed water molecules, protonic concentration was enhanced. Super strong acid was prepared by fixing SO_4^<2-> functional group on the surface of ZrO_2 particles. However, only small improvement of the conductivity in comparison to pure ZrO_2 particle was observed.(3) Novel Ln(OH)_3(Ln : Lanthanide) materials were chosen for investigation. Ln(OH)_3 showed wide range of conductivities depending on lanthanide element and less hysteresis during heating and cooling cycle. The conductivities are 10^<-2>〜10^<-3>Scm^<-1>. These materials still open for discussion, but have possibility that proton move mainly by hopping between OH bonds.