Pavlovich Anastasiya, Pankratov Alexander, Dunyushkina Liliya
Institute of High Temperature Electrochemistry, Ural Branch of the Russian Academy of Sciences, 20 Akademicheskaya St., 620066 Ekaterinburg, Russia.
Membranes (Basel). 2023 Jul 12;13(7):663. doi: 10.3390/membranes13070663.
SrZrO-based perovskites are promising proton-conducting membranes for use in fuel and electrolysis cells, sensors, hydrogen separators, etc., because they combine good proton conductivity with excellent chemical stability. In the present research, the effect of Lu-doping on microstructure, phase composition, and electrical conductivity of SrZrLuxO (x = 0-0.10) was investigated via X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and impedance spectroscopy. Dense ceramic samples were obtained by the solution combustion synthesis and possessed an orthorhombic perovskite-type structure. The solubility limit of Lu was revealed to lie between x = 0.03 and 0.05. The conductivity of SrZrLuO increases strongly with the addition of Lu at x < 0.05 and just slightly changes at x > 0.05. The rise of the water vapor partial pressure results in an increase in the conductivity of SrZrLuxO ceramics, which confirms their hydration ability and significant contribution of protonic defects to the charge transfer. The highest conductivity was achieved at x = 0.10 (10 mS cm at 700 °C, wet air, pHO = 0.61 kPa). The conductivity behavior was discussed in terms of the defect formation model, taking into account the improvement in ceramic sintering at high lutetium concentrations.
基于SrZrO的钙钛矿是用于燃料电池、电解槽、传感器、氢分离器等的有前景的质子传导膜，因为它们兼具良好的质子传导性和出色的化学稳定性。在本研究中，通过X射线衍射、扫描电子显微镜、能量色散X射线光谱和阻抗谱研究了Lu掺杂对SrZrLuxO（x = 0 - 0.10）的微观结构、相组成和电导率的影响。通过溶液燃烧合成获得了致密的陶瓷样品，其具有正交钙钛矿型结构。发现Lu的溶解度极限在x = 0.03至0.05之间。在x < 0.05时，SrZrLuO的电导率随着Lu的添加而强烈增加，而在x > 0.05时仅略有变化。水蒸气分压的升高导致SrZrLuxO陶瓷的电导率增加，这证实了它们的水合能力以及质子缺陷对电荷转移的重大贡献。在x = 0.10时达到最高电导率（700 °C、湿空气、pHO = 0.61 kPa下为10 mS cm）。考虑到高镥浓度下陶瓷烧结的改善，根据缺陷形成模型对电导率行为进行了讨论。
