Proton conductors have potential applications such as fuel cells, electrolysis cells, and sensors. These applications require new materials with high proton conductivity and high chemical stability at intermediate temperatures. Herein we report a series of new hexagonal perovskite-related oxides, Ba₅R₂Al₂SnO₁₃ (R = Gd, Dy, Ho, Y, Er, Tm, and Yb). Ba₅Er₂Al₂SnO₁₃ exhibited a high proton conductivity without chemical doping (e.g., 0.01 S cm^–1 at 303 °C), which is attributed to its high proton concentration and diffusion coefficient. The high diffusion coefficient of Ba₅Er₂Al₂SnO₁₃ can be attributed to the fast proton migration in the octahedral layers. The high proton concentration is attributed to full hydration in hydrated Ba₅Er₂Al₂SnO₁₃ and the large amount of intrinsic oxygen vacancies in the dry sample, as evidenced by both neutron diffraction and thermogravimetric analysis. Ba₅Er₂Al₂SnO₁₃ was found to exhibit high chemical stability under wet atmospheres of O₂, air, H₂, and CO₂. High proton conductivity and high chemical stability indicate that Ba₅Er₂Al₂SnO₁₃ is a superior proton conductor. Ba₅R₂Al₂SnO₁₃ (R = Gd, Dy, Ho, Y, Tm, and Yb) exhibited high electrical conductivity in wet N₂, suggesting that these materials also exhibit high proton conductivity. These findings will open new avenues for proton conductors. The high proton conductivity via full hydration and fast proton migration in octahedral layers in highly oxygen-deficient hexagonal perovskite-related materials would be an effective strategy for developing next-generation proton conductors.

中文翻译：

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完全水合六方钙钛矿相关氧化物八面体层的高质子传导


质子导体具有潜在的应用，例如燃料电池、电解池和传感器。这些应用需要在中间温度下具有高质子传导性和高化学稳定性的新材料。在此，我们报道了一系列新的六方钙钛矿相关氧化物Ba ₅ R ₂ Al ₂ SnO ₁₃ ( R = Gd、Dy、Ho、Y、Er、Tm 和 Yb)。 Ba ₅ Er ₂ Al ₂ SnO ₁₃在没有化学掺杂的情况下表现出高质子电导率（例如，303℃时为0.01 S cm ^–1 ），这归因于其高质子浓度和扩散系数。 Ba ₅ Er ₂ Al ₂ SnO ₁₃的高扩散系数可归因于八面体层中质子的快速迁移。高质子浓度归因于水合Ba ₅ Er ₂ Al ₂ SnO ₁₃中的完全水合以及干燥样品中大量的固有氧空位，如中子衍射和热重分析所证明的。发现Ba ₅ Er ₂ Al ₂ SnO ₁₃在O ₂ 、空气、H ₂和CO ₂的潮湿气氛下表现出高化学稳定性。高质子传导率和高化学稳定性表明Ba ₅ Er ₂ Al ₂ SnO ₁₃是一种优异的质子导体。 Ba ₅ R ₂ Al ₂ SnO ₁₃ ( R =Gd、Dy、Ho、Y、Tm和Yb)在湿N ₂中表现出高电导率，这表明这些材料也表现出高质子电导率。这些发现将为质子导体开辟新的途径。在高度缺氧的六方钙钛矿相关材料的八面体层中通过完全水合和快速质子迁移而获得的高质子电导率将是开发下一代质子导体的有效策略。